Merge branch 'master' into fix10193

src/compiler/binder.ts

@@ -27,7 +27,7 @@ namespace ts {
             return ModuleInstanceState.ConstEnumOnly;
         }
         // 3. non-exported import declarations
-        else if ((node.kind === SyntaxKind.ImportDeclaration || node.kind === SyntaxKind.ImportEqualsDeclaration) && !(node.flags & NodeFlags.Export)) {
+        else if ((node.kind === SyntaxKind.ImportDeclaration || node.kind === SyntaxKind.ImportEqualsDeclaration) && !(hasModifier(node, ModifierFlags.Export))) {
             return ModuleInstanceState.NonInstantiated;
         }
         // 4. other uninstantiated module declarations.
@@ -131,6 +131,10 @@ namespace ts {
         const unreachableFlow: FlowNode = { flags: FlowFlags.Unreachable };
         const reportedUnreachableFlow: FlowNode = { flags: FlowFlags.Unreachable };
 
+        // state used to aggregate transform flags during bind.
+        let subtreeTransformFlags: TransformFlags = TransformFlags.None;
+        let skipTransformFlagAggregation: boolean;
+
         function bindSourceFile(f: SourceFile, opts: CompilerOptions) {
             file = f;
             options = opts;
@@ -138,6 +142,7 @@ namespace ts {
             inStrictMode = !!file.externalModuleIndicator;
             classifiableNames = createMap<string>();
             symbolCount = 0;
+            skipTransformFlagAggregation = isDeclarationFile(file);
 
             Symbol = objectAllocator.getSymbolConstructor();
 
@@ -164,6 +169,7 @@ namespace ts {
             activeLabels = undefined;
             hasExplicitReturn = false;
             emitFlags = NodeFlags.None;
+            subtreeTransformFlags = TransformFlags.None;
         }
 
         return bindSourceFile;
@@ -253,7 +259,7 @@ namespace ts {
 
                 case SyntaxKind.FunctionDeclaration:
                 case SyntaxKind.ClassDeclaration:
-                    return node.flags & NodeFlags.Default ? "default" : undefined;
+                    return hasModifier(node, ModifierFlags.Default) ? "default" : undefined;
                 case SyntaxKind.JSDocFunctionType:
                     return isJSDocConstructSignature(node) ? "__new" : "__call";
                 case SyntaxKind.Parameter:
@@ -262,7 +268,7 @@ namespace ts {
                     Debug.assert(node.parent.kind === SyntaxKind.JSDocFunctionType);
                     let functionType = <JSDocFunctionType>node.parent;
                     let index = indexOf(functionType.parameters, node);
-                    return "p" + index;
+                    return "arg" + index;
                 case SyntaxKind.JSDocTypedefTag:
                     const parentNode = node.parent && node.parent.parent;
                     let nameFromParentNode: string;
@@ -293,7 +299,7 @@ namespace ts {
         function declareSymbol(symbolTable: SymbolTable, parent: Symbol, node: Declaration, includes: SymbolFlags, excludes: SymbolFlags): Symbol {
             Debug.assert(!hasDynamicName(node));
 
-            const isDefaultExport = node.flags & NodeFlags.Default;
+            const isDefaultExport = hasModifier(node, ModifierFlags.Default);
 
             // The exported symbol for an export default function/class node is always named "default"
             const name = isDefaultExport && parent ? "default" : getDeclarationName(node);
@@ -385,7 +391,7 @@ namespace ts {
         }
 
         function declareModuleMember(node: Declaration, symbolFlags: SymbolFlags, symbolExcludes: SymbolFlags): Symbol {
-            const hasExportModifier = getCombinedNodeFlags(node) & NodeFlags.Export;
+            const hasExportModifier = getCombinedModifierFlags(node) & ModifierFlags.Export;
             if (symbolFlags & SymbolFlags.Alias) {
                 if (node.kind === SyntaxKind.ExportSpecifier || (node.kind === SyntaxKind.ImportEqualsDeclaration && hasExportModifier)) {
                     return declareSymbol(container.symbol.exports, container.symbol, node, symbolFlags, symbolExcludes);
@@ -526,13 +532,28 @@ namespace ts {
         }
 
         function bindChildren(node: Node): void {
+            if (skipTransformFlagAggregation) {
+                bindChildrenWorker(node);
+            }
+            else if (node.transformFlags & TransformFlags.HasComputedFlags) {
+                skipTransformFlagAggregation = true;
+                bindChildrenWorker(node);
+                skipTransformFlagAggregation = false;
+            }
+            else {
+                const savedSubtreeTransformFlags = subtreeTransformFlags;
+                subtreeTransformFlags = 0;
+                bindChildrenWorker(node);
+                subtreeTransformFlags = savedSubtreeTransformFlags | computeTransformFlagsForNode(node, subtreeTransformFlags);
+            }
+        }
+
+        function bindChildrenWorker(node: Node): void {
             // Binding of JsDocComment should be done before the current block scope container changes.
             // because the scope of JsDocComment should not be affected by whether the current node is a
             // container or not.
             if (isInJavaScriptFile(node) && node.jsDocComments) {
-                for (const jsDocComment of node.jsDocComments) {
-                    bind(jsDocComment);
-                }
+                forEach(node.jsDocComments, bind);
             }
             if (checkUnreachable(node)) {
                 forEachChild(node, bind);
@@ -581,6 +602,9 @@ namespace ts {
                 case SyntaxKind.PrefixUnaryExpression:
                     bindPrefixUnaryExpressionFlow(<PrefixUnaryExpression>node);
                     break;
+                case SyntaxKind.PostfixUnaryExpression:
+                    bindPostfixUnaryExpressionFlow(<PostfixUnaryExpression>node);
+                    break;
                 case SyntaxKind.BinaryExpression:
                     bindBinaryExpressionFlow(<BinaryExpression>node);
                     break;
@@ -1096,6 +1120,16 @@ namespace ts {
             }
             else {
                 forEachChild(node, bind);
+                if (node.operator === SyntaxKind.PlusEqualsToken || node.operator === SyntaxKind.MinusMinusToken) {
+                    bindAssignmentTargetFlow(node.operand);
+                }
+            }
+        }
+
+        function bindPostfixUnaryExpressionFlow(node: PostfixUnaryExpression) {
+            forEachChild(node, bind);
+            if (node.operator === SyntaxKind.PlusPlusToken || node.operator === SyntaxKind.MinusMinusToken) {
+                bindAssignmentTargetFlow(node.operand);
             }
         }
 
@@ -1140,8 +1174,8 @@ namespace ts {
             currentFlow = finishFlowLabel(postExpressionLabel);
         }
 
-        function bindInitializedVariableFlow(node: VariableDeclaration | BindingElement) {
-            const name = node.name;
+        function bindInitializedVariableFlow(node: VariableDeclaration | ArrayBindingElement) {
+            const name = !isOmittedExpression(node) ? node.name : undefined;
             if (isBindingPattern(name)) {
                 for (const child of name.elements) {
                     bindInitializedVariableFlow(child);
@@ -1321,7 +1355,7 @@ namespace ts {
         }
 
         function declareClassMember(node: Declaration, symbolFlags: SymbolFlags, symbolExcludes: SymbolFlags) {
-            return node.flags & NodeFlags.Static
+            return hasModifier(node, ModifierFlags.Static)
                 ? declareSymbol(container.symbol.exports, container.symbol, node, symbolFlags, symbolExcludes)
                 : declareSymbol(container.symbol.members, container.symbol, node, symbolFlags, symbolExcludes);
         }
@@ -1358,7 +1392,7 @@ namespace ts {
         function bindModuleDeclaration(node: ModuleDeclaration) {
             setExportContextFlag(node);
             if (isAmbientModule(node)) {
-                if (node.flags & NodeFlags.Export) {
+                if (hasModifier(node, ModifierFlags.Export)) {
                     errorOnFirstToken(node, Diagnostics.export_modifier_cannot_be_applied_to_ambient_modules_and_module_augmentations_since_they_are_always_visible);
                 }
                 if (isExternalModuleAugmentation(node)) {
@@ -1625,7 +1659,7 @@ namespace ts {
             }
         }
 
-        function checkStrictModeNumericLiteral(node: LiteralExpression) {
+        function checkStrictModeNumericLiteral(node: NumericLiteral) {
             if (inStrictMode && node.isOctalLiteral) {
                 file.bindDiagnostics.push(createDiagnosticForNode(node, Diagnostics.Octal_literals_are_not_allowed_in_strict_mode));
             }
@@ -1700,6 +1734,9 @@ namespace ts {
                 }
                 parent = saveParent;
             }
+            else if (!skipTransformFlagAggregation && (node.transformFlags & TransformFlags.HasComputedFlags) === 0) {
+                subtreeTransformFlags |= computeTransformFlagsForNode(node, 0);
+            }
             inStrictMode = saveInStrictMode;
         }
 
@@ -1770,7 +1807,7 @@ namespace ts {
                 case SyntaxKind.DeleteExpression:
                     return checkStrictModeDeleteExpression(<DeleteExpression>node);
                 case SyntaxKind.NumericLiteral:
-                    return checkStrictModeNumericLiteral(<LiteralExpression>node);
+                    return checkStrictModeNumericLiteral(<NumericLiteral>node);
                 case SyntaxKind.PostfixUnaryExpression:
                     return checkStrictModePostfixUnaryExpression(<PostfixUnaryExpression>node);
                 case SyntaxKind.PrefixUnaryExpression:
@@ -1802,7 +1839,7 @@ namespace ts {
                     return bindPropertyOrMethodOrAccessor(<Declaration>node, SymbolFlags.EnumMember, SymbolFlags.EnumMemberExcludes);
 
                 case SyntaxKind.JsxSpreadAttribute:
-                    emitFlags |= NodeFlags.HasJsxSpreadAttribute;
+                    emitFlags |= NodeFlags.HasJsxSpreadAttributes;
                     return;
 
                 case SyntaxKind.CallSignature:
@@ -2220,7 +2257,7 @@ namespace ts {
             if (currentFlow === unreachableFlow) {
                 const reportError =
                     // report error on all statements except empty ones
-                    (isStatement(node) && node.kind !== SyntaxKind.EmptyStatement) ||
+                    (isStatementButNotDeclaration(node) && node.kind !== SyntaxKind.EmptyStatement) ||
                     // report error on class declarations
                     node.kind === SyntaxKind.ClassDeclaration ||
                     // report error on instantiated modules or const-enums only modules if preserveConstEnums is set
@@ -2257,4 +2294,763 @@ namespace ts {
             return true;
         }
     }
+
+    /**
+     * Computes the transform flags for a node, given the transform flags of its subtree
+     *
+     * @param node The node to analyze
+     * @param subtreeFlags Transform flags computed for this node's subtree
+     */
+    export function computeTransformFlagsForNode(node: Node, subtreeFlags: TransformFlags): TransformFlags {
+        const kind = node.kind;
+        switch (kind) {
+            case SyntaxKind.CallExpression:
+                return computeCallExpression(<CallExpression>node, subtreeFlags);
+
+            case SyntaxKind.ModuleDeclaration:
+                return computeModuleDeclaration(<ModuleDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.ParenthesizedExpression:
+                return computeParenthesizedExpression(<ParenthesizedExpression>node, subtreeFlags);
+
+            case SyntaxKind.BinaryExpression:
+                return computeBinaryExpression(<BinaryExpression>node, subtreeFlags);
+
+            case SyntaxKind.ExpressionStatement:
+                return computeExpressionStatement(<ExpressionStatement>node, subtreeFlags);
+
+            case SyntaxKind.Parameter:
+                return computeParameter(<ParameterDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.ArrowFunction:
+                return computeArrowFunction(<ArrowFunction>node, subtreeFlags);
+
+            case SyntaxKind.FunctionExpression:
+                return computeFunctionExpression(<FunctionExpression>node, subtreeFlags);
+
+            case SyntaxKind.FunctionDeclaration:
+                return computeFunctionDeclaration(<FunctionDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.VariableDeclaration:
+                return computeVariableDeclaration(<VariableDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.VariableDeclarationList:
+                return computeVariableDeclarationList(<VariableDeclarationList>node, subtreeFlags);
+
+            case SyntaxKind.VariableStatement:
+                return computeVariableStatement(<VariableStatement>node, subtreeFlags);
+
+            case SyntaxKind.LabeledStatement:
+                return computeLabeledStatement(<LabeledStatement>node, subtreeFlags);
+
+            case SyntaxKind.ClassDeclaration:
+                return computeClassDeclaration(<ClassDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.ClassExpression:
+                return computeClassExpression(<ClassExpression>node, subtreeFlags);
+
+            case SyntaxKind.HeritageClause:
+                return computeHeritageClause(<HeritageClause>node, subtreeFlags);
+
+            case SyntaxKind.ExpressionWithTypeArguments:
+                return computeExpressionWithTypeArguments(<ExpressionWithTypeArguments>node, subtreeFlags);
+
+            case SyntaxKind.Constructor:
+                return computeConstructor(<ConstructorDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.PropertyDeclaration:
+                return computePropertyDeclaration(<PropertyDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.MethodDeclaration:
+                return computeMethod(<MethodDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.GetAccessor:
+            case SyntaxKind.SetAccessor:
+                return computeAccessor(<AccessorDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.ImportEqualsDeclaration:
+                return computeImportEquals(<ImportEqualsDeclaration>node, subtreeFlags);
+
+            case SyntaxKind.PropertyAccessExpression:
+                return computePropertyAccess(<PropertyAccessExpression>node, subtreeFlags);
+
+            default:
+                return computeOther(node, kind, subtreeFlags);
+        }
+    }
+
+    function computeCallExpression(node: CallExpression, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const expression = node.expression;
+        const expressionKind = expression.kind;
+
+        if (subtreeFlags & TransformFlags.ContainsSpreadElementExpression
+            || isSuperOrSuperProperty(expression, expressionKind)) {
+            // If the this node contains a SpreadElementExpression, or is a super call, then it is an ES6
+            // node.
+            transformFlags |= TransformFlags.AssertES6;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.ArrayLiteralOrCallOrNewExcludes;
+    }
+
+    function isSuperOrSuperProperty(node: Node, kind: SyntaxKind) {
+        switch (kind) {
+            case SyntaxKind.SuperKeyword:
+                return true;
+
+            case SyntaxKind.PropertyAccessExpression:
+            case SyntaxKind.ElementAccessExpression:
+                const expression = (<PropertyAccessExpression | ElementAccessExpression>node).expression;
+                const expressionKind = expression.kind;
+                return expressionKind === SyntaxKind.SuperKeyword;
+        }
+
+        return false;
+    }
+
+    function computeBinaryExpression(node: BinaryExpression, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const operatorTokenKind = node.operatorToken.kind;
+        const leftKind = node.left.kind;
+
+        if (operatorTokenKind === SyntaxKind.EqualsToken
+            && (leftKind === SyntaxKind.ObjectLiteralExpression
+                || leftKind === SyntaxKind.ArrayLiteralExpression)) {
+            // Destructuring assignments are ES6 syntax.
+            transformFlags |= TransformFlags.AssertES6 | TransformFlags.DestructuringAssignment;
+        }
+        else if (operatorTokenKind === SyntaxKind.AsteriskAsteriskToken
+            || operatorTokenKind === SyntaxKind.AsteriskAsteriskEqualsToken) {
+            // Exponentiation is ES7 syntax.
+            transformFlags |= TransformFlags.AssertES7;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeParameter(node: ParameterDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const modifierFlags = getModifierFlags(node);
+        const name = node.name;
+        const initializer = node.initializer;
+        const dotDotDotToken = node.dotDotDotToken;
+
+        // If the parameter has a question token, then it is TypeScript syntax.
+        if (node.questionToken) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        // If the parameter's name is 'this', then it is TypeScript syntax.
+        if (subtreeFlags & TransformFlags.ContainsDecorators
+            || (name && isIdentifier(name) && name.originalKeywordKind === SyntaxKind.ThisKeyword)) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        // If a parameter has an accessibility modifier, then it is TypeScript syntax.
+        if (modifierFlags & ModifierFlags.ParameterPropertyModifier) {
+            transformFlags |= TransformFlags.AssertTypeScript | TransformFlags.ContainsParameterPropertyAssignments;
+        }
+
+        // If a parameter has an initializer, a binding pattern or a dotDotDot token, then
+        // it is ES6 syntax and its container must emit default value assignments or parameter destructuring downlevel.
+        if (subtreeFlags & TransformFlags.ContainsBindingPattern || initializer || dotDotDotToken) {
+            transformFlags |= TransformFlags.AssertES6 | TransformFlags.ContainsDefaultValueAssignments;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.ParameterExcludes;
+    }
+
+    function computeParenthesizedExpression(node: ParenthesizedExpression, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const expression = node.expression;
+        const expressionKind = expression.kind;
+        const expressionTransformFlags = expression.transformFlags;
+
+        // If the node is synthesized, it means the emitter put the parentheses there,
+        // not the user. If we didn't want them, the emitter would not have put them
+        // there.
+        if (expressionKind === SyntaxKind.AsExpression
+            || expressionKind === SyntaxKind.TypeAssertionExpression) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        // If the expression of a ParenthesizedExpression is a destructuring assignment,
+        // then the ParenthesizedExpression is a destructuring assignment.
+        if (expressionTransformFlags & TransformFlags.DestructuringAssignment) {
+            transformFlags |= TransformFlags.DestructuringAssignment;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeClassDeclaration(node: ClassDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags: TransformFlags;
+        const modifierFlags = getModifierFlags(node);
+
+        if (modifierFlags & ModifierFlags.Ambient) {
+            // An ambient declaration is TypeScript syntax.
+            transformFlags = TransformFlags.AssertTypeScript;
+        }
+        else {
+            // A ClassDeclaration is ES6 syntax.
+            transformFlags = subtreeFlags | TransformFlags.AssertES6;
+
+            // A class with a parameter property assignment, property initializer, or decorator is
+            // TypeScript syntax.
+            // An exported declaration may be TypeScript syntax.
+            if ((subtreeFlags & TransformFlags.TypeScriptClassSyntaxMask)
+                || (modifierFlags & ModifierFlags.Export)) {
+                transformFlags |= TransformFlags.AssertTypeScript;
+            }
+
+            if (subtreeFlags & TransformFlags.ContainsLexicalThisInComputedPropertyName) {
+                // A computed property name containing `this` might need to be rewritten,
+                // so propagate the ContainsLexicalThis flag upward.
+                transformFlags |= TransformFlags.ContainsLexicalThis;
+            }
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.ClassExcludes;
+    }
+
+    function computeClassExpression(node: ClassExpression, subtreeFlags: TransformFlags) {
+        // A ClassExpression is ES6 syntax.
+        let transformFlags = subtreeFlags | TransformFlags.AssertES6;
+
+        // A class with a parameter property assignment, property initializer, or decorator is
+        // TypeScript syntax.
+        if (subtreeFlags & TransformFlags.TypeScriptClassSyntaxMask) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        if (subtreeFlags & TransformFlags.ContainsLexicalThisInComputedPropertyName) {
+            // A computed property name containing `this` might need to be rewritten,
+            // so propagate the ContainsLexicalThis flag upward.
+            transformFlags |= TransformFlags.ContainsLexicalThis;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.ClassExcludes;
+    }
+
+    function computeHeritageClause(node: HeritageClause, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+
+        switch (node.token) {
+            case SyntaxKind.ExtendsKeyword:
+                // An `extends` HeritageClause is ES6 syntax.
+                transformFlags |= TransformFlags.AssertES6;
+                break;
+
+            case SyntaxKind.ImplementsKeyword:
+                // An `implements` HeritageClause is TypeScript syntax.
+                transformFlags |= TransformFlags.AssertTypeScript;
+                break;
+
+            default:
+                Debug.fail("Unexpected token for heritage clause");
+                break;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeExpressionWithTypeArguments(node: ExpressionWithTypeArguments, subtreeFlags: TransformFlags) {
+        // An ExpressionWithTypeArguments is ES6 syntax, as it is used in the
+        // extends clause of a class.
+        let transformFlags = subtreeFlags | TransformFlags.AssertES6;
+
+        // If an ExpressionWithTypeArguments contains type arguments, then it
+        // is TypeScript syntax.
+        if (node.typeArguments) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeConstructor(node: ConstructorDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const body = node.body;
+
+        if (body === undefined) {
+            // An overload constructor is TypeScript syntax.
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.ConstructorExcludes;
+    }
+
+    function computeMethod(node: MethodDeclaration, subtreeFlags: TransformFlags) {
+        // A MethodDeclaration is ES6 syntax.
+        let transformFlags = subtreeFlags | TransformFlags.AssertES6;
+        const modifierFlags = getModifierFlags(node);
+        const body = node.body;
+        const typeParameters = node.typeParameters;
+        const asteriskToken = node.asteriskToken;
+
+        // A MethodDeclaration is TypeScript syntax if it is either async, abstract, overloaded,
+        // generic, or has a decorator.
+        if (!body
+            || typeParameters
+            || (modifierFlags & (ModifierFlags.Async | ModifierFlags.Abstract))
+            || (subtreeFlags & TransformFlags.ContainsDecorators)) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        // Currently, we only support generators that were originally async function bodies.
+        if (asteriskToken && getEmitFlags(node) & EmitFlags.AsyncFunctionBody) {
+            transformFlags |= TransformFlags.AssertGenerator;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.MethodOrAccessorExcludes;
+    }
+
+    function computeAccessor(node: AccessorDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const modifierFlags = getModifierFlags(node);
+        const body = node.body;
+
+        // A MethodDeclaration is TypeScript syntax if it is either async, abstract, overloaded,
+        // generic, or has a decorator.
+        if (!body
+            || (modifierFlags & (ModifierFlags.Async | ModifierFlags.Abstract))
+            || (subtreeFlags & TransformFlags.ContainsDecorators)) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.MethodOrAccessorExcludes;
+    }
+
+    function computePropertyDeclaration(node: PropertyDeclaration, subtreeFlags: TransformFlags) {
+        // A PropertyDeclaration is TypeScript syntax.
+        let transformFlags = subtreeFlags | TransformFlags.AssertTypeScript;
+
+        // If the PropertyDeclaration has an initializer, we need to inform its ancestor
+        // so that it handle the transformation.
+        if (node.initializer) {
+            transformFlags |= TransformFlags.ContainsPropertyInitializer;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeFunctionDeclaration(node: FunctionDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags: TransformFlags;
+        const modifierFlags = getModifierFlags(node);
+        const body = node.body;
+        const asteriskToken = node.asteriskToken;
+
+        if (!body || (modifierFlags & ModifierFlags.Ambient)) {
+            // An ambient declaration is TypeScript syntax.
+            // A FunctionDeclaration without a body is an overload and is TypeScript syntax.
+            transformFlags = TransformFlags.AssertTypeScript;
+        }
+        else {
+            transformFlags = subtreeFlags | TransformFlags.ContainsHoistedDeclarationOrCompletion;
+
+            // If a FunctionDeclaration is exported, then it is either ES6 or TypeScript syntax.
+            if (modifierFlags & ModifierFlags.Export) {
+                transformFlags |= TransformFlags.AssertTypeScript | TransformFlags.AssertES6;
+            }
+
+            // If a FunctionDeclaration is async, then it is TypeScript syntax.
+            if (modifierFlags & ModifierFlags.Async) {
+                transformFlags |= TransformFlags.AssertTypeScript;
+            }
+
+            // If a FunctionDeclaration's subtree has marked the container as needing to capture the
+            // lexical this, or the function contains parameters with initializers, then this node is
+            // ES6 syntax.
+            if (subtreeFlags & TransformFlags.ES6FunctionSyntaxMask) {
+                transformFlags |= TransformFlags.AssertES6;
+            }
+
+            // If a FunctionDeclaration is generator function and is the body of a
+            // transformed async function, then this node can be transformed to a
+            // down-level generator.
+            // Currently we do not support transforming any other generator fucntions
+            // down level.
+            if (asteriskToken && getEmitFlags(node) & EmitFlags.AsyncFunctionBody) {
+                transformFlags |= TransformFlags.AssertGenerator;
+            }
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.FunctionExcludes;
+    }
+
+    function computeFunctionExpression(node: FunctionExpression, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const modifierFlags = getModifierFlags(node);
+        const asteriskToken = node.asteriskToken;
+
+        // An async function expression is TypeScript syntax.
+        if (modifierFlags & ModifierFlags.Async) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        // If a FunctionExpression's subtree has marked the container as needing to capture the
+        // lexical this, or the function contains parameters with initializers, then this node is
+        // ES6 syntax.
+        if (subtreeFlags & TransformFlags.ES6FunctionSyntaxMask) {
+            transformFlags |= TransformFlags.AssertES6;
+        }
+
+        // If a FunctionExpression is generator function and is the body of a
+        // transformed async function, then this node can be transformed to a
+        // down-level generator.
+        // Currently we do not support transforming any other generator fucntions
+        // down level.
+        if (asteriskToken && getEmitFlags(node) & EmitFlags.AsyncFunctionBody) {
+            transformFlags |= TransformFlags.AssertGenerator;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.FunctionExcludes;
+    }
+
+    function computeArrowFunction(node: ArrowFunction, subtreeFlags: TransformFlags) {
+        // An ArrowFunction is ES6 syntax, and excludes markers that should not escape the scope of an ArrowFunction.
+        let transformFlags = subtreeFlags | TransformFlags.AssertES6;
+        const modifierFlags = getModifierFlags(node);
+
+        // An async arrow function is TypeScript syntax.
+        if (modifierFlags & ModifierFlags.Async) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        // If an ArrowFunction contains a lexical this, its container must capture the lexical this.
+        if (subtreeFlags & TransformFlags.ContainsLexicalThis) {
+            transformFlags |= TransformFlags.ContainsCapturedLexicalThis;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.ArrowFunctionExcludes;
+    }
+
+    function computePropertyAccess(node: PropertyAccessExpression, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const expression = node.expression;
+        const expressionKind = expression.kind;
+
+        // If a PropertyAccessExpression starts with a super keyword, then it is
+        // ES6 syntax, and requires a lexical `this` binding.
+        if (expressionKind === SyntaxKind.SuperKeyword) {
+            transformFlags |= TransformFlags.ContainsLexicalThis;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeVariableDeclaration(node: VariableDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+        const nameKind = node.name.kind;
+
+        // A VariableDeclaration with a binding pattern is ES6 syntax.
+        if (nameKind === SyntaxKind.ObjectBindingPattern || nameKind === SyntaxKind.ArrayBindingPattern) {
+            transformFlags |= TransformFlags.AssertES6 | TransformFlags.ContainsBindingPattern;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeVariableStatement(node: VariableStatement, subtreeFlags: TransformFlags) {
+        let transformFlags: TransformFlags;
+        const modifierFlags = getModifierFlags(node);
+        const declarationListTransformFlags = node.declarationList.transformFlags;
+
+        // An ambient declaration is TypeScript syntax.
+        if (modifierFlags & ModifierFlags.Ambient) {
+            transformFlags = TransformFlags.AssertTypeScript;
+        }
+        else {
+            transformFlags = subtreeFlags;
+
+            // If a VariableStatement is exported, then it is either ES6 or TypeScript syntax.
+            if (modifierFlags & ModifierFlags.Export) {
+                transformFlags |= TransformFlags.AssertES6 | TransformFlags.AssertTypeScript;
+            }
+
+            if (declarationListTransformFlags & TransformFlags.ContainsBindingPattern) {
+                transformFlags |= TransformFlags.AssertES6;
+            }
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeLabeledStatement(node: LabeledStatement, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+
+        // A labeled statement containing a block scoped binding *may* need to be transformed from ES6.
+        if (subtreeFlags & TransformFlags.ContainsBlockScopedBinding
+            && isIterationStatement(node, /*lookInLabeledStatements*/ true)) {
+            transformFlags |= TransformFlags.AssertES6;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeImportEquals(node: ImportEqualsDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+
+        // An ImportEqualsDeclaration with a namespace reference is TypeScript.
+        if (!isExternalModuleImportEqualsDeclaration(node)) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeExpressionStatement(node: ExpressionStatement, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags;
+
+        // If the expression of an expression statement is a destructuring assignment,
+        // then we treat the statement as ES6 so that we can indicate that we do not
+        // need to hold on to the right-hand side.
+        if (node.expression.transformFlags & TransformFlags.DestructuringAssignment) {
+            transformFlags |= TransformFlags.AssertES6;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.NodeExcludes;
+    }
+
+    function computeModuleDeclaration(node: ModuleDeclaration, subtreeFlags: TransformFlags) {
+        let transformFlags = TransformFlags.AssertTypeScript;
+        const modifierFlags = getModifierFlags(node);
+
+        if ((modifierFlags & ModifierFlags.Ambient) === 0) {
+            transformFlags |= subtreeFlags;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.ModuleExcludes;
+    }
+
+    function computeVariableDeclarationList(node: VariableDeclarationList, subtreeFlags: TransformFlags) {
+        let transformFlags = subtreeFlags | TransformFlags.ContainsHoistedDeclarationOrCompletion;
+
+        if (subtreeFlags & TransformFlags.ContainsBindingPattern) {
+            transformFlags |= TransformFlags.AssertES6;
+        }
+
+        // If a VariableDeclarationList is `let` or `const`, then it is ES6 syntax.
+        if (node.flags & NodeFlags.BlockScoped) {
+            transformFlags |= TransformFlags.AssertES6 | TransformFlags.ContainsBlockScopedBinding;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~TransformFlags.VariableDeclarationListExcludes;
+    }
+
+    function computeOther(node: Node, kind: SyntaxKind, subtreeFlags: TransformFlags) {
+        // Mark transformations needed for each node
+        let transformFlags = subtreeFlags;
+        let excludeFlags = TransformFlags.NodeExcludes;
+
+        switch (kind) {
+            case SyntaxKind.PublicKeyword:
+            case SyntaxKind.PrivateKeyword:
+            case SyntaxKind.ProtectedKeyword:
+            case SyntaxKind.AbstractKeyword:
+            case SyntaxKind.DeclareKeyword:
+            case SyntaxKind.AsyncKeyword:
+            case SyntaxKind.ConstKeyword:
+            case SyntaxKind.AwaitExpression:
+            case SyntaxKind.EnumDeclaration:
+            case SyntaxKind.EnumMember:
+            case SyntaxKind.TypeAssertionExpression:
+            case SyntaxKind.AsExpression:
+            case SyntaxKind.NonNullExpression:
+            case SyntaxKind.ReadonlyKeyword:
+                // These nodes are TypeScript syntax.
+                transformFlags |= TransformFlags.AssertTypeScript;
+                break;
+
+            case SyntaxKind.JsxElement:
+            case SyntaxKind.JsxSelfClosingElement:
+            case SyntaxKind.JsxOpeningElement:
+            case SyntaxKind.JsxText:
+            case SyntaxKind.JsxClosingElement:
+            case SyntaxKind.JsxAttribute:
+            case SyntaxKind.JsxSpreadAttribute:
+            case SyntaxKind.JsxExpression:
+                // These nodes are Jsx syntax.
+                transformFlags |= TransformFlags.AssertJsx;
+                break;
+
+            case SyntaxKind.ExportKeyword:
+                // This node is both ES6 and TypeScript syntax.
+                transformFlags |= TransformFlags.AssertES6 | TransformFlags.AssertTypeScript;
+                break;
+
+            case SyntaxKind.DefaultKeyword:
+            case SyntaxKind.NoSubstitutionTemplateLiteral:
+            case SyntaxKind.TemplateHead:
+            case SyntaxKind.TemplateMiddle:
+            case SyntaxKind.TemplateTail:
+            case SyntaxKind.TemplateExpression:
+            case SyntaxKind.TaggedTemplateExpression:
+            case SyntaxKind.ShorthandPropertyAssignment:
+            case SyntaxKind.ForOfStatement:
+                // These nodes are ES6 syntax.
+                transformFlags |= TransformFlags.AssertES6;
+                break;
+
+            case SyntaxKind.YieldExpression:
+                // This node is ES6 syntax.
+                transformFlags |= TransformFlags.AssertES6 | TransformFlags.ContainsYield;
+                break;
+
+            case SyntaxKind.AnyKeyword:
+            case SyntaxKind.NumberKeyword:
+            case SyntaxKind.NeverKeyword:
+            case SyntaxKind.StringKeyword:
+            case SyntaxKind.BooleanKeyword:
+            case SyntaxKind.SymbolKeyword:
+            case SyntaxKind.VoidKeyword:
+            case SyntaxKind.TypeParameter:
+            case SyntaxKind.PropertySignature:
+            case SyntaxKind.MethodSignature:
+            case SyntaxKind.CallSignature:
+            case SyntaxKind.ConstructSignature:
+            case SyntaxKind.IndexSignature:
+            case SyntaxKind.TypePredicate:
+            case SyntaxKind.TypeReference:
+            case SyntaxKind.FunctionType:
+            case SyntaxKind.ConstructorType:
+            case SyntaxKind.TypeQuery:
+            case SyntaxKind.TypeLiteral:
+            case SyntaxKind.ArrayType:
+            case SyntaxKind.TupleType:
+            case SyntaxKind.UnionType:
+            case SyntaxKind.IntersectionType:
+            case SyntaxKind.ParenthesizedType:
+            case SyntaxKind.InterfaceDeclaration:
+            case SyntaxKind.TypeAliasDeclaration:
+            case SyntaxKind.ThisType:
+            case SyntaxKind.LiteralType:
+                // Types and signatures are TypeScript syntax, and exclude all other facts.
+                transformFlags = TransformFlags.AssertTypeScript;
+                excludeFlags = TransformFlags.TypeExcludes;
+                break;
+
+            case SyntaxKind.ComputedPropertyName:
+                // Even though computed property names are ES6, we don't treat them as such.
+                // This is so that they can flow through PropertyName transforms unaffected.
+                // Instead, we mark the container as ES6, so that it can properly handle the transform.
+                transformFlags |= TransformFlags.ContainsComputedPropertyName;
+                if (subtreeFlags & TransformFlags.ContainsLexicalThis) {
+                    // A computed method name like `[this.getName()](x: string) { ... }` needs to
+                    // distinguish itself from the normal case of a method body containing `this`:
+                    // `this` inside a method doesn't need to be rewritten (the method provides `this`),
+                    // whereas `this` inside a computed name *might* need to be rewritten if the class/object
+                    // is inside an arrow function:
+                    // `_this = this; () => class K { [_this.getName()]() { ... } }`
+                    // To make this distinction, use ContainsLexicalThisInComputedPropertyName
+                    // instead of ContainsLexicalThis for computed property names
+                    transformFlags |= TransformFlags.ContainsLexicalThisInComputedPropertyName;
+                }
+                break;
+
+            case SyntaxKind.SpreadElementExpression:
+                // This node is ES6 syntax, but is handled by a containing node.
+                transformFlags |= TransformFlags.ContainsSpreadElementExpression;
+                break;
+
+            case SyntaxKind.SuperKeyword:
+                // This node is ES6 syntax.
+                transformFlags |= TransformFlags.AssertES6;
+                break;
+
+            case SyntaxKind.ThisKeyword:
+                // Mark this node and its ancestors as containing a lexical `this` keyword.
+                transformFlags |= TransformFlags.ContainsLexicalThis;
+                break;
+
+            case SyntaxKind.ObjectBindingPattern:
+            case SyntaxKind.ArrayBindingPattern:
+                // These nodes are ES6 syntax.
+                transformFlags |= TransformFlags.AssertES6 | TransformFlags.ContainsBindingPattern;
+                break;
+
+            case SyntaxKind.Decorator:
+                // This node is TypeScript syntax, and marks its container as also being TypeScript syntax.
+                transformFlags |= TransformFlags.AssertTypeScript | TransformFlags.ContainsDecorators;
+                break;
+
+            case SyntaxKind.ObjectLiteralExpression:
+                excludeFlags = TransformFlags.ObjectLiteralExcludes;
+                if (subtreeFlags & TransformFlags.ContainsComputedPropertyName) {
+                    // If an ObjectLiteralExpression contains a ComputedPropertyName, then it
+                    // is an ES6 node.
+                    transformFlags |= TransformFlags.AssertES6;
+                }
+
+                if (subtreeFlags & TransformFlags.ContainsLexicalThisInComputedPropertyName) {
+                    // A computed property name containing `this` might need to be rewritten,
+                    // so propagate the ContainsLexicalThis flag upward.
+                    transformFlags |= TransformFlags.ContainsLexicalThis;
+                }
+
+                break;
+
+            case SyntaxKind.ArrayLiteralExpression:
+            case SyntaxKind.NewExpression:
+                excludeFlags = TransformFlags.ArrayLiteralOrCallOrNewExcludes;
+                if (subtreeFlags & TransformFlags.ContainsSpreadElementExpression) {
+                    // If the this node contains a SpreadElementExpression, then it is an ES6
+                    // node.
+                    transformFlags |= TransformFlags.AssertES6;
+                }
+
+                break;
+
+            case SyntaxKind.DoStatement:
+            case SyntaxKind.WhileStatement:
+            case SyntaxKind.ForStatement:
+            case SyntaxKind.ForInStatement:
+                // A loop containing a block scoped binding *may* need to be transformed from ES6.
+                if (subtreeFlags & TransformFlags.ContainsBlockScopedBinding) {
+                    transformFlags |= TransformFlags.AssertES6;
+                }
+
+                break;
+
+            case SyntaxKind.SourceFile:
+                if (subtreeFlags & TransformFlags.ContainsCapturedLexicalThis) {
+                    transformFlags |= TransformFlags.AssertES6;
+                }
+
+                break;
+
+            case SyntaxKind.ReturnStatement:
+            case SyntaxKind.ContinueStatement:
+            case SyntaxKind.BreakStatement:
+                transformFlags |= TransformFlags.ContainsHoistedDeclarationOrCompletion;
+                break;
+        }
+
+        node.transformFlags = transformFlags | TransformFlags.HasComputedFlags;
+        return transformFlags & ~excludeFlags;
+    }
 }

src/compiler/commandLineParser.ts

@@ -5,12 +5,15 @@
 /// <reference path="scanner.ts"/>
 
 namespace ts {
+    /* @internal */
+    export const compileOnSaveCommandLineOption: CommandLineOption = { name: "compileOnSave", type: "boolean" };
     /* @internal */
     export const optionDeclarations: CommandLineOption[] = [
         {
             name: "charset",
             type: "string",
         },
+        compileOnSaveCommandLineOption,
         {
             name: "declaration",
             shortName: "d",
@@ -30,6 +33,7 @@ namespace ts {
         {
             name: "extendedDiagnostics",
             type: "boolean",
+            experimental: true
         },
         {
             name: "emitBOM",
@@ -126,6 +130,10 @@ namespace ts {
             type: "boolean",
             description: Diagnostics.Do_not_emit_outputs_if_any_errors_were_reported,
         },
+        {
+            name: "noErrorTruncation",
+            type: "boolean"
+        },
         {
             name: "noImplicitAny",
             type: "boolean",
@@ -289,6 +297,7 @@ namespace ts {
                 "classic": ModuleResolutionKind.Classic,
             }),
             description: Diagnostics.Specify_module_resolution_strategy_Colon_node_Node_js_or_classic_TypeScript_pre_1_6,
+            paramType: Diagnostics.STRATEGY,
         },
         {
             name: "allowUnusedLabels",
@@ -402,6 +411,7 @@ namespace ts {
                     "es2017": "lib.es2017.d.ts",
                     // Host only
                     "dom": "lib.dom.d.ts",
+                    "dom.iterable": "lib.dom.iterable.d.ts",
                     "webworker": "lib.webworker.d.ts",
                     "scripthost": "lib.scripthost.d.ts",
                     // ES2015 Or ESNext By-feature options
@@ -429,6 +439,11 @@ namespace ts {
             name: "strictNullChecks",
             type: "boolean",
             description: Diagnostics.Enable_strict_null_checks
+        },
+        {
+            name: "importHelpers",
+            type: "boolean",
+            description: Diagnostics.Import_emit_helpers_from_tslib
         }
     ];
 
@@ -462,6 +477,14 @@ namespace ts {
         shortOptionNames: Map<string>;
     }
 
+    /* @internal */
+    export const defaultInitCompilerOptions: CompilerOptions = {
+        module: ModuleKind.CommonJS,
+        target: ScriptTarget.ES5,
+        noImplicitAny: false,
+        sourceMap: false,
+    };
+
     let optionNameMapCache: OptionNameMap;
 
     /* @internal */
@@ -657,16 +680,104 @@ namespace ts {
       * @param fileName The path to the config file
       * @param jsonText The text of the config file
       */
-    export function parseConfigFileTextToJson(fileName: string, jsonText: string): { config?: any; error?: Diagnostic } {
+    export function parseConfigFileTextToJson(fileName: string, jsonText: string, stripComments = true): { config?: any; error?: Diagnostic } {
         try {
-            const jsonTextWithoutComments = removeComments(jsonText);
-            return { config: /\S/.test(jsonTextWithoutComments) ? JSON.parse(jsonTextWithoutComments) : {} };
+            const jsonTextToParse = stripComments ? removeComments(jsonText) : jsonText;
+            return { config: /\S/.test(jsonTextToParse) ? JSON.parse(jsonTextToParse) : {} };
         }
         catch (e) {
             return { error: createCompilerDiagnostic(Diagnostics.Failed_to_parse_file_0_Colon_1, fileName, e.message) };
         }
     }
 
+    /**
+     * Generate tsconfig configuration when running command line "--init"
+     * @param options commandlineOptions to be generated into tsconfig.json
+     * @param fileNames array of filenames to be generated into tsconfig.json
+     */
+    /* @internal */
+    export function generateTSConfig(options: CompilerOptions, fileNames: string[]): { compilerOptions: Map<CompilerOptionsValue> } {
+        const compilerOptions = extend(options, defaultInitCompilerOptions);
+        const configurations: any = {
+            compilerOptions: serializeCompilerOptions(compilerOptions)
+        };
+        if (fileNames && fileNames.length) {
+            // only set the files property if we have at least one file
+            configurations.files = fileNames;
+        }
+
+        return configurations;
+
+        function getCustomTypeMapOfCommandLineOption(optionDefinition: CommandLineOption): Map<string | number> | undefined {
+            if (optionDefinition.type === "string" || optionDefinition.type === "number" || optionDefinition.type === "boolean") {
+                // this is of a type CommandLineOptionOfPrimitiveType
+                return undefined;
+            }
+            else if (optionDefinition.type === "list") {
+                return getCustomTypeMapOfCommandLineOption((<CommandLineOptionOfListType>optionDefinition).element);
+            }
+            else {
+                return (<CommandLineOptionOfCustomType>optionDefinition).type;
+            }
+        }
+
+        function getNameOfCompilerOptionValue(value: CompilerOptionsValue, customTypeMap: MapLike<string | number>): string | undefined {
+            // There is a typeMap associated with this command-line option so use it to map value back to its name
+            for (const key in customTypeMap) {
+                if (customTypeMap[key] === value) {
+                    return key;
+                }
+            }
+            return undefined;
+        }
+
+        function serializeCompilerOptions(options: CompilerOptions): Map<CompilerOptionsValue> {
+            const result = createMap<CompilerOptionsValue>();
+            const optionsNameMap = getOptionNameMap().optionNameMap;
+
+            for (const name in options) {
+                if (hasProperty(options, name)) {
+                    // tsconfig only options cannot be specified via command line,
+                    // so we can assume that only types that can appear here string | number | boolean
+                    switch (name) {
+                        case "init":
+                        case "watch":
+                        case "version":
+                        case "help":
+                        case "project":
+                            break;
+                        default:
+                            const value = options[name];
+                            let optionDefinition = optionsNameMap[name.toLowerCase()];
+                            if (optionDefinition) {
+                                const customTypeMap = getCustomTypeMapOfCommandLineOption(optionDefinition);
+                                if (!customTypeMap) {
+                                    // There is no map associated with this compiler option then use the value as-is
+                                    // This is the case if the value is expect to be string, number, boolean or list of string
+                                    result[name] = value;
+                                }
+                                else {
+                                    if (optionDefinition.type === "list") {
+                                        const convertedValue: string[] = [];
+                                        for (const element of value as (string | number)[]) {
+                                            convertedValue.push(getNameOfCompilerOptionValue(element, customTypeMap));
+                                        }
+                                        result[name] = convertedValue;
+                                    }
+                                    else {
+                                        // There is a typeMap associated with this command-line option so use it to map value back to its name
+                                        result[name] = getNameOfCompilerOptionValue(value, customTypeMap);
+                                    }
+                                }
+                            }
+                            break;
+                    }
+                }
+            }
+            return result;
+        }
+    }
+
     /**
      * Remove the comments from a json like text.
      * Comments can be single line comments (starting with # or //) or multiline comments using / * * /
@@ -699,15 +810,49 @@ namespace ts {
       * @param basePath A root directory to resolve relative path entries in the config
       *    file to. e.g. outDir
       */
-    export function parseJsonConfigFileContent(json: any, host: ParseConfigHost, basePath: string, existingOptions: CompilerOptions = {}, configFileName?: string): ParsedCommandLine {
+    export function parseJsonConfigFileContent(json: any, host: ParseConfigHost, basePath: string, existingOptions: CompilerOptions = {}, configFileName?: string, resolutionStack: Path[] = []): ParsedCommandLine {
         const errors: Diagnostic[] = [];
-        const compilerOptions: CompilerOptions = convertCompilerOptionsFromJsonWorker(json["compilerOptions"], basePath, errors, configFileName);
-        const options = extend(existingOptions, compilerOptions);
+        const getCanonicalFileName = createGetCanonicalFileName(host.useCaseSensitiveFileNames);
+        const resolvedPath = toPath(configFileName || "", basePath, getCanonicalFileName);
+        if (resolutionStack.indexOf(resolvedPath) >= 0) {
+            return {
+                options: {},
+                fileNames: [],
+                typingOptions: {},
+                raw: json,
+                errors: [createCompilerDiagnostic(Diagnostics.Circularity_detected_while_resolving_configuration_Colon_0, [...resolutionStack, resolvedPath].join(" -> "))],
+                wildcardDirectories: {}
+            };
+        }
+
+        let options: CompilerOptions = convertCompilerOptionsFromJsonWorker(json["compilerOptions"], basePath, errors, configFileName);
         const typingOptions: TypingOptions = convertTypingOptionsFromJsonWorker(json["typingOptions"], basePath, errors, configFileName);
 
+        if (json["extends"]) {
+            let [include, exclude, files, baseOptions]: [string[], string[], string[], CompilerOptions] = [undefined, undefined, undefined, {}];
+            if (typeof json["extends"] === "string") {
+                [include, exclude, files, baseOptions] = (tryExtendsName(json["extends"]) || [include, exclude, files, baseOptions]);
+            }
+            else {
+                errors.push(createCompilerDiagnostic(Diagnostics.Compiler_option_0_requires_a_value_of_type_1, "extends", "string"));
+            }
+            if (include && !json["include"]) {
+                json["include"] = include;
+            }
+            if (exclude && !json["exclude"]) {
+                json["exclude"] = exclude;
+            }
+            if (files && !json["files"]) {
+                json["files"] = files;
+            }
+            options = assign({}, baseOptions, options);
+        }
+
+        options = extend(existingOptions, options);
         options.configFilePath = configFileName;
 
         const { fileNames, wildcardDirectories } = getFileNames(errors);
+        const compileOnSave = convertCompileOnSaveOptionFromJson(json, basePath, errors);
 
         return {
             options,
@@ -715,9 +860,43 @@ namespace ts {
             typingOptions,
             raw: json,
             errors,
-            wildcardDirectories
+            wildcardDirectories,
+            compileOnSave
         };
 
+        function tryExtendsName(extendedConfig: string): [string[], string[], string[], CompilerOptions] {
+            // If the path isn't a rooted or relative path, don't try to resolve it (we reserve the right to special case module-id like paths in the future)
+            if (!(isRootedDiskPath(extendedConfig) || startsWith(normalizeSlashes(extendedConfig), "./") || startsWith(normalizeSlashes(extendedConfig), "../"))) {
+                errors.push(createCompilerDiagnostic(Diagnostics.The_path_in_an_extends_options_must_be_relative_or_rooted));
+                return;
+            }
+            let extendedConfigPath = toPath(extendedConfig, basePath, getCanonicalFileName);
+            if (!host.fileExists(extendedConfigPath) && !endsWith(extendedConfigPath, ".json")) {
+                extendedConfigPath = `${extendedConfigPath}.json` as Path;
+                if (!host.fileExists(extendedConfigPath)) {
+                    errors.push(createCompilerDiagnostic(Diagnostics.File_0_does_not_exist, extendedConfig));
+                    return;
+                }
+            }
+            const extendedResult = readConfigFile(extendedConfigPath, path => host.readFile(path));
+            if (extendedResult.error) {
+                errors.push(extendedResult.error);
+                return;
+            }
+            const extendedDirname = getDirectoryPath(extendedConfigPath);
+            const relativeDifference = convertToRelativePath(extendedDirname, basePath, getCanonicalFileName);
+            const updatePath: (path: string) => string = path => isRootedDiskPath(path) ? path : combinePaths(relativeDifference, path);
+            // Merge configs (copy the resolution stack so it is never reused between branches in potential diamond-problem scenarios)
+            const result = parseJsonConfigFileContent(extendedResult.config, host, extendedDirname, /*existingOptions*/undefined, getBaseFileName(extendedConfigPath), resolutionStack.concat([resolvedPath]));
+            errors.push(...result.errors);
+            const [include, exclude, files] = map(["include", "exclude", "files"], key => {
+                if (!json[key] && extendedResult.config[key]) {
+                    return map(extendedResult.config[key], updatePath);
+                }
+            });
+            return [include, exclude, files, result.options];
+        }
+
         function getFileNames(errors: Diagnostic[]): ExpandResult {
             let fileNames: string[];
             if (hasProperty(json, "files")) {
@@ -752,14 +931,13 @@ namespace ts {
                 errors.push(createCompilerDiagnostic(Diagnostics.Unknown_option_excludes_Did_you_mean_exclude));
             }
             else {
-                // By default, exclude common package folders
+                // By default, exclude common package folders and the outDir
                 excludeSpecs = ["node_modules", "bower_components", "jspm_packages"];
-            }
 
-            // Always exclude the output directory unless explicitly included
-            const outDir = json["compilerOptions"] && json["compilerOptions"]["outDir"];
-            if (outDir) {
-                excludeSpecs.push(outDir);
+                const outDir = json["compilerOptions"] && json["compilerOptions"]["outDir"];
+                if (outDir) {
+                    excludeSpecs.push(outDir);
+                }
             }
 
             if (fileNames === undefined && includeSpecs === undefined) {
@@ -770,13 +948,24 @@ namespace ts {
         }
     }
 
+    export function convertCompileOnSaveOptionFromJson(jsonOption: any, basePath: string, errors: Diagnostic[]): boolean {
+        if (!hasProperty(jsonOption, compileOnSaveCommandLineOption.name)) {
+            return false;
+        }
+        const result = convertJsonOption(compileOnSaveCommandLineOption, jsonOption["compileOnSave"], basePath, errors);
+        if (typeof result === "boolean" && result) {
+            return result;
+        }
+        return false;
+    }
+
     export function convertCompilerOptionsFromJson(jsonOptions: any, basePath: string, configFileName?: string): { options: CompilerOptions, errors: Diagnostic[] } {
         const errors: Diagnostic[] = [];
         const options = convertCompilerOptionsFromJsonWorker(jsonOptions, basePath, errors, configFileName);
         return { options, errors };
     }
 
-    export function convertTypingOptionsFromJson(jsonOptions: any, basePath: string, configFileName?: string): { options: CompilerOptions, errors: Diagnostic[] } {
+    export function convertTypingOptionsFromJson(jsonOptions: any, basePath: string, configFileName?: string): { options: TypingOptions, errors: Diagnostic[] } {
         const errors: Diagnostic[] = [];
         const options = convertTypingOptionsFromJsonWorker(jsonOptions, basePath, errors, configFileName);
         return { options, errors };
@@ -785,7 +974,9 @@ namespace ts {
     function convertCompilerOptionsFromJsonWorker(jsonOptions: any,
         basePath: string, errors: Diagnostic[], configFileName?: string): CompilerOptions {
 
-        const options: CompilerOptions = getBaseFileName(configFileName) === "jsconfig.json" ? { allowJs: true } : {};
+        const options: CompilerOptions = getBaseFileName(configFileName) === "jsconfig.json"
+            ? { allowJs: true, maxNodeModuleJsDepth: 2, allowSyntheticDefaultImports: true }
+            : {};
         convertOptionsFromJson(optionDeclarations, jsonOptions, basePath, options, Diagnostics.Unknown_compiler_option_0, errors);
         return options;
     }

src/compiler/comments.ts

@@ -0,0 +1,347 @@
+/// <reference path="sourcemap.ts" />
+
+/* @internal */
+namespace ts {
+    export interface CommentWriter {
+        reset(): void;
+        setSourceFile(sourceFile: SourceFile): void;
+        emitNodeWithComments(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void): void;
+        emitBodyWithDetachedComments(node: Node, detachedRange: TextRange, emitCallback: (node: Node) => void): void;
+        emitTrailingCommentsOfPosition(pos: number): void;
+    }
+
+    export function createCommentWriter(host: EmitHost, writer: EmitTextWriter, sourceMap: SourceMapWriter): CommentWriter {
+        const compilerOptions = host.getCompilerOptions();
+        const extendedDiagnostics = compilerOptions.extendedDiagnostics;
+        const newLine = host.getNewLine();
+        const { emitPos } = sourceMap;
+
+        let containerPos = -1;
+        let containerEnd = -1;
+        let declarationListContainerEnd = -1;
+        let currentSourceFile: SourceFile;
+        let currentText: string;
+        let currentLineMap: number[];
+        let detachedCommentsInfo: { nodePos: number, detachedCommentEndPos: number}[];
+        let hasWrittenComment = false;
+        let disabled: boolean = compilerOptions.removeComments;
+
+        return {
+            reset,
+            setSourceFile,
+            emitNodeWithComments,
+            emitBodyWithDetachedComments,
+            emitTrailingCommentsOfPosition,
+        };
+
+        function emitNodeWithComments(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void) {
+            if (disabled) {
+                emitCallback(emitContext, node);
+                return;
+            }
+
+            if (node) {
+                const { pos, end } = getCommentRange(node);
+                const emitFlags = getEmitFlags(node);
+                if ((pos < 0 && end < 0) || (pos === end)) {
+                    // Both pos and end are synthesized, so just emit the node without comments.
+                    if (emitFlags & EmitFlags.NoNestedComments) {
+                        disabled = true;
+                        emitCallback(emitContext, node);
+                        disabled = false;
+                    }
+                    else {
+                        emitCallback(emitContext, node);
+                    }
+                }
+                else {
+                    if (extendedDiagnostics) {
+                        performance.mark("preEmitNodeWithComment");
+                    }
+
+                    const isEmittedNode = node.kind !== SyntaxKind.NotEmittedStatement;
+                    const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0;
+                    const skipTrailingComments = end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0;
+
+                    // Emit leading comments if the position is not synthesized and the node
+                    // has not opted out from emitting leading comments.
+                    if (!skipLeadingComments) {
+                        emitLeadingComments(pos, isEmittedNode);
+                    }
+
+                    // Save current container state on the stack.
+                    const savedContainerPos = containerPos;
+                    const savedContainerEnd = containerEnd;
+                    const savedDeclarationListContainerEnd = declarationListContainerEnd;
+
+                    if (!skipLeadingComments) {
+                        containerPos = pos;
+                    }
+
+                    if (!skipTrailingComments) {
+                        containerEnd = end;
+
+                        // To avoid invalid comment emit in a down-level binding pattern, we
+                        // keep track of the last declaration list container's end
+                        if (node.kind === SyntaxKind.VariableDeclarationList) {
+                            declarationListContainerEnd = end;
+                        }
+                    }
+
+                    if (extendedDiagnostics) {
+                        performance.measure("commentTime", "preEmitNodeWithComment");
+                    }
+
+                    if (emitFlags & EmitFlags.NoNestedComments) {
+                        disabled = true;
+                        emitCallback(emitContext, node);
+                        disabled = false;
+                    }
+                    else {
+                        emitCallback(emitContext, node);
+                    }
+
+                    if (extendedDiagnostics) {
+                        performance.mark("beginEmitNodeWithComment");
+                    }
+
+                    // Restore previous container state.
+                    containerPos = savedContainerPos;
+                    containerEnd = savedContainerEnd;
+                    declarationListContainerEnd = savedDeclarationListContainerEnd;
+
+                    // Emit trailing comments if the position is not synthesized and the node
+                    // has not opted out from emitting leading comments and is an emitted node.
+                    if (!skipTrailingComments && isEmittedNode) {
+                        emitTrailingComments(end);
+                    }
+
+                    if (extendedDiagnostics) {
+                        performance.measure("commentTime", "beginEmitNodeWithComment");
+                    }
+                }
+            }
+        }
+
+        function emitBodyWithDetachedComments(node: Node, detachedRange: TextRange, emitCallback: (node: Node) => void) {
+            if (extendedDiagnostics) {
+                performance.mark("preEmitBodyWithDetachedComments");
+            }
+
+            const { pos, end } = detachedRange;
+            const emitFlags = getEmitFlags(node);
+            const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0;
+            const skipTrailingComments = disabled || end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0;
+
+            if (!skipLeadingComments) {
+                emitDetachedCommentsAndUpdateCommentsInfo(detachedRange);
+            }
+
+            if (extendedDiagnostics) {
+                performance.measure("commentTime", "preEmitBodyWithDetachedComments");
+            }
+
+            if (emitFlags & EmitFlags.NoNestedComments && !disabled) {
+                disabled = true;
+                emitCallback(node);
+                disabled = false;
+            }
+            else {
+                emitCallback(node);
+            }
+
+            if (extendedDiagnostics) {
+                performance.mark("beginEmitBodyWithDetachedCommetns");
+            }
+
+            if (!skipTrailingComments) {
+                emitLeadingComments(detachedRange.end, /*isEmittedNode*/ true);
+            }
+
+            if (extendedDiagnostics) {
+                performance.measure("commentTime", "beginEmitBodyWithDetachedCommetns");
+            }
+        }
+
+        function emitLeadingComments(pos: number, isEmittedNode: boolean) {
+            hasWrittenComment = false;
+
+            if (isEmittedNode) {
+                forEachLeadingCommentToEmit(pos, emitLeadingComment);
+            }
+            else if (pos === 0) {
+                // If the node will not be emitted in JS, remove all the comments(normal, pinned and ///) associated with the node,
+                // unless it is a triple slash comment at the top of the file.
+                // For Example:
+                //      /// <reference-path ...>
+                //      declare var x;
+                //      /// <reference-path ...>
+                //      interface F {}
+                //  The first /// will NOT be removed while the second one will be removed even though both node will not be emitted
+                forEachLeadingCommentToEmit(pos, emitTripleSlashLeadingComment);
+            }
+        }
+
+        function emitTripleSlashLeadingComment(commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean, rangePos: number) {
+            if (isTripleSlashComment(commentPos, commentEnd)) {
+                emitLeadingComment(commentPos, commentEnd, kind, hasTrailingNewLine, rangePos);
+            }
+        }
+
+        function emitLeadingComment(commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean, rangePos: number) {
+            if (!hasWrittenComment) {
+                emitNewLineBeforeLeadingCommentOfPosition(currentLineMap, writer, rangePos, commentPos);
+                hasWrittenComment = true;
+            }
+
+            // Leading comments are emitted at /*leading comment1 */space/*leading comment*/space
+            emitPos(commentPos);
+            writeCommentRange(currentText, currentLineMap, writer, commentPos, commentEnd, newLine);
+            emitPos(commentEnd);
+
+            if (hasTrailingNewLine) {
+                writer.writeLine();
+            }
+            else {
+                writer.write(" ");
+            }
+        }
+
+        function emitTrailingComments(pos: number) {
+            forEachTrailingCommentToEmit(pos, emitTrailingComment);
+        }
+
+        function emitTrailingComment(commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean) {
+            // trailing comments are emitted at space/*trailing comment1 */space/*trailing comment2*/
+            if (!writer.isAtStartOfLine()) {
+                writer.write(" ");
+            }
+
+            emitPos(commentPos);
+            writeCommentRange(currentText, currentLineMap, writer, commentPos, commentEnd, newLine);
+            emitPos(commentEnd);
+
+            if (hasTrailingNewLine) {
+                writer.writeLine();
+            }
+        }
+
+        function emitTrailingCommentsOfPosition(pos: number) {
+            if (disabled) {
+                return;
+            }
+
+            if (extendedDiagnostics) {
+                performance.mark("beforeEmitTrailingCommentsOfPosition");
+            }
+
+            forEachTrailingCommentToEmit(pos, emitTrailingCommentOfPosition);
+
+            if (extendedDiagnostics) {
+                performance.measure("commentTime", "beforeEmitTrailingCommentsOfPosition");
+            }
+        }
+
+        function emitTrailingCommentOfPosition(commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean) {
+            // trailing comments of a position are emitted at /*trailing comment1 */space/*trailing comment*/space
+
+            emitPos(commentPos);
+            writeCommentRange(currentText, currentLineMap, writer, commentPos, commentEnd, newLine);
+            emitPos(commentEnd);
+
+            if (hasTrailingNewLine) {
+                writer.writeLine();
+            }
+            else {
+                writer.write(" ");
+            }
+        }
+
+        function forEachLeadingCommentToEmit(pos: number, cb: (commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean, rangePos: number) => void) {
+            // Emit the leading comments only if the container's pos doesn't match because the container should take care of emitting these comments
+            if (containerPos === -1 || pos !== containerPos) {
+                if (hasDetachedComments(pos)) {
+                    forEachLeadingCommentWithoutDetachedComments(cb);
+                }
+                else {
+                    forEachLeadingCommentRange(currentText, pos, cb, /*state*/ pos);
+                }
+            }
+        }
+
+        function forEachTrailingCommentToEmit(end: number, cb: (commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean) => void) {
+            // Emit the trailing comments only if the container's end doesn't match because the container should take care of emitting these comments
+            if (containerEnd === -1 || (end !== containerEnd && end !== declarationListContainerEnd)) {
+                forEachTrailingCommentRange(currentText, end, cb);
+            }
+        }
+
+        function reset() {
+            currentSourceFile = undefined;
+            currentText = undefined;
+            currentLineMap = undefined;
+            detachedCommentsInfo = undefined;
+        }
+
+        function setSourceFile(sourceFile: SourceFile) {
+            currentSourceFile = sourceFile;
+            currentText = currentSourceFile.text;
+            currentLineMap = getLineStarts(currentSourceFile);
+            detachedCommentsInfo = undefined;
+        }
+
+        function hasDetachedComments(pos: number) {
+            return detachedCommentsInfo !== undefined && lastOrUndefined(detachedCommentsInfo).nodePos === pos;
+        }
+
+        function forEachLeadingCommentWithoutDetachedComments(cb: (commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean, rangePos: number) => void) {
+            // get the leading comments from detachedPos
+            const pos = lastOrUndefined(detachedCommentsInfo).detachedCommentEndPos;
+            if (detachedCommentsInfo.length - 1) {
+                detachedCommentsInfo.pop();
+            }
+            else {
+                detachedCommentsInfo = undefined;
+            }
+
+            forEachLeadingCommentRange(currentText, pos, cb, /*state*/ pos);
+        }
+
+        function emitDetachedCommentsAndUpdateCommentsInfo(range: TextRange) {
+            const currentDetachedCommentInfo = emitDetachedComments(currentText, currentLineMap, writer, writeComment, range, newLine, disabled);
+            if (currentDetachedCommentInfo) {
+                if (detachedCommentsInfo) {
+                    detachedCommentsInfo.push(currentDetachedCommentInfo);
+                }
+                else {
+                    detachedCommentsInfo = [currentDetachedCommentInfo];
+                }
+            }
+        }
+
+        function writeComment(text: string, lineMap: number[], writer: EmitTextWriter, commentPos: number, commentEnd: number, newLine: string) {
+            emitPos(commentPos);
+            writeCommentRange(text, lineMap, writer, commentPos, commentEnd, newLine);
+            emitPos(commentEnd);
+        }
+
+        /**
+         * Determine if the given comment is a triple-slash
+         *
+         * @return true if the comment is a triple-slash comment else false
+         **/
+        function isTripleSlashComment(commentPos: number, commentEnd: number) {
+            // Verify this is /// comment, but do the regexp match only when we first can find /// in the comment text
+            // so that we don't end up computing comment string and doing match for all // comments
+            if (currentText.charCodeAt(commentPos + 1) === CharacterCodes.slash &&
+                commentPos + 2 < commentEnd &&
+                currentText.charCodeAt(commentPos + 2) === CharacterCodes.slash) {
+                const textSubStr = currentText.substring(commentPos, commentEnd);
+                return textSubStr.match(fullTripleSlashReferencePathRegEx) ||
+                    textSubStr.match(fullTripleSlashAMDReferencePathRegEx) ?
+                    true : false;
+            }
+            return false;
+        }
+    }
+}

src/compiler/core.ts

@@ -1,7 +1,6 @@
-/// <reference path="types.ts"/>
+/// <reference path="types.ts"/>
 /// <reference path="performance.ts" />
 
-
 /* @internal */
 namespace ts {
     /**
@@ -47,6 +46,7 @@ namespace ts {
             contains,
             remove,
             forEachValue: forEachValueInMap,
+            getKeys,
             clear,
         };
 
@@ -56,6 +56,14 @@ namespace ts {
             }
         }
 
+        function getKeys() {
+            const keys: Path[] = [];
+            for (const key in files) {
+                keys.push(<Path>key);
+            }
+            return keys;
+        }
+
         // path should already be well-formed so it does not need to be normalized
         function get(path: Path): T {
             return files[toKey(path)];
@@ -113,8 +121,39 @@ namespace ts {
         return undefined;
     }
 
-    /** Like `forEach`, but assumes existence of array and fails if no truthy value is found. */
-    export function find<T, U>(array: T[], callback: (element: T, index: number) => U | undefined): U {
+    /**
+     * Iterates through `array` by index and performs the callback on each element of array until the callback
+     * returns a falsey value, then returns false.
+     * If no such value is found, the callback is applied to each element of array and `true` is returned.
+     */
+    export function every<T>(array: T[], callback: (element: T, index: number) => boolean): boolean {
+        if (array) {
+            for (let i = 0, len = array.length; i < len; i++) {
+                if (!callback(array[i], i)) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
+    /** Works like Array.prototype.find, returning `undefined` if no element satisfying the predicate is found. */
+    export function find<T>(array: T[], predicate: (element: T, index: number) => boolean): T | undefined {
+        for (let i = 0, len = array.length; i < len; i++) {
+            const value = array[i];
+            if (predicate(value, i)) {
+                return value;
+            }
+        }
+        return undefined;
+    }
+
+    /**
+     * Returns the first truthy result of `callback`, or else fails.
+     * This is like `forEach`, but never returns undefined.
+     */
+    export function findMap<T, U>(array: T[], callback: (element: T, index: number) => U | undefined): U {
         for (let i = 0, len = array.length; i < len; i++) {
             const result = callback(array[i], i);
             if (result) {
@@ -155,11 +194,12 @@ namespace ts {
         return -1;
     }
 
-    export function countWhere<T>(array: T[], predicate: (x: T) => boolean): number {
+    export function countWhere<T>(array: T[], predicate: (x: T, i: number) => boolean): number {
         let count = 0;
         if (array) {
-            for (const v of array) {
-                if (predicate(v)) {
+            for (let i = 0; i < array.length; i++) {
+                const v = array[i];
+                if (predicate(v, i)) {
                     count++;
                 }
             }
@@ -171,6 +211,8 @@ namespace ts {
      * Filters an array by a predicate function. Returns the same array instance if the predicate is
      * true for all elements, otherwise returns a new array instance containing the filtered subset.
      */
+    export function filter<T, U extends T>(array: T[], f: (x: T) => x is U): U[];
+    export function filter<T>(array: T[], f: (x: T) => boolean): T[]
     export function filter<T>(array: T[], f: (x: T) => boolean): T[] {
         if (array) {
             const len = array.length;
@@ -218,12 +260,140 @@ namespace ts {
         array.length = outIndex;
     }
 
-    export function map<T, U>(array: T[], f: (x: T) => U): U[] {
+    export function map<T, U>(array: T[], f: (x: T, i: number) => U): U[] {
         let result: U[];
+        if (array) {
+            result = [];
+            for (let i = 0; i < array.length; i++) {
+                const v = array[i];
+                result.push(f(v, i));
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Flattens an array containing a mix of array or non-array elements.
+     *
+     * @param array The array to flatten.
+     */
+    export function flatten<T>(array: (T | T[])[]): T[] {
+        let result: T[];
         if (array) {
             result = [];
             for (const v of array) {
-                result.push(f(v));
+                if (v) {
+                    if (isArray(v)) {
+                        addRange(result, v);
+                    }
+                    else {
+                        result.push(v);
+                    }
+                }
+            }
+        }
+
+        return result;
+    }
+
+    /**
+     * Maps an array. If the mapped value is an array, it is spread into the result.
+     *
+     * @param array The array to map.
+     * @param mapfn The callback used to map the result into one or more values.
+     */
+    export function flatMap<T, U>(array: T[], mapfn: (x: T, i: number) => U | U[]): U[] {
+        let result: U[];
+        if (array) {
+            result = [];
+            for (let i = 0; i < array.length; i++) {
+                const v = mapfn(array[i], i);
+                if (v) {
+                    if (isArray(v)) {
+                        addRange(result, v);
+                    }
+                    else {
+                        result.push(v);
+                    }
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Computes the first matching span of elements and returns a tuple of the first span
+     * and the remaining elements.
+     */
+    export function span<T>(array: T[], f: (x: T, i: number) => boolean): [T[], T[]] {
+        if (array) {
+            for (let i = 0; i < array.length; i++) {
+                if (!f(array[i], i)) {
+                    return [array.slice(0, i), array.slice(i)];
+                }
+            }
+            return [array.slice(0), []];
+        }
+
+        return undefined;
+    }
+
+    /**
+     * Maps contiguous spans of values with the same key.
+     *
+     * @param array The array to map.
+     * @param keyfn A callback used to select the key for an element.
+     * @param mapfn A callback used to map a contiguous chunk of values to a single value.
+     */
+    export function spanMap<T, K, U>(array: T[], keyfn: (x: T, i: number) => K, mapfn: (chunk: T[], key: K, start: number, end: number) => U): U[] {
+        let result: U[];
+        if (array) {
+            result = [];
+            const len = array.length;
+            let previousKey: K;
+            let key: K;
+            let start = 0;
+            let pos = 0;
+            while (start < len) {
+                while (pos < len) {
+                    const value = array[pos];
+                    key = keyfn(value, pos);
+                    if (pos === 0) {
+                        previousKey = key;
+                    }
+                    else if (key !== previousKey) {
+                        break;
+                    }
+
+                    pos++;
+                }
+
+                if (start < pos) {
+                    const v = mapfn(array.slice(start, pos), previousKey, start, pos);
+                    if (v) {
+                        result.push(v);
+                    }
+
+                    start = pos;
+                }
+
+                previousKey = key;
+                pos++;
+            }
+        }
+
+        return result;
+    }
+
+    export function mapObject<T, U>(object: MapLike<T>, f: (key: string, x: T) => [string, U]): MapLike<U> {
+        let result: MapLike<U>;
+        if (object) {
+            result = {};
+            for (const v of getOwnKeys(object)) {
+                const [key, value]: [string, U] = f(v, object[v]) || [undefined, undefined];
+                if (key !== undefined) {
+                    result[key] = value;
+                }
             }
         }
         return result;
@@ -232,10 +402,10 @@ namespace ts {
     export function concatenate<T>(array1: T[], array2: T[]): T[] {
         if (!array2 || !array2.length) return array1;
         if (!array1 || !array1.length) return array2;
-
-        return array1.concat(array2);
+        return [...array1, ...array2];
     }
 
+    // TODO: fixme (N^2) - add optional comparer so collection can be sorted before deduplication.
     export function deduplicate<T>(array: T[], areEqual?: (a: T, b: T) => boolean): T[] {
         let result: T[];
         if (array) {
@@ -252,6 +422,27 @@ namespace ts {
         return result;
     }
 
+    /**
+     * Compacts an array, removing any falsey elements.
+     */
+    export function compact<T>(array: T[]): T[] {
+        let result: T[];
+        if (array) {
+            for (let i = 0; i < array.length; i++) {
+                const v = array[i];
+                if (result || !v) {
+                    if (!result) {
+                        result = array.slice(0, i);
+                    }
+                    if (v) {
+                        result.push(v);
+                    }
+                }
+            }
+        }
+        return result || array;
+    }
+
     export function sum(array: any[], prop: string): number {
         let result = 0;
         for (const v of array) {
@@ -263,7 +454,9 @@ namespace ts {
     export function addRange<T>(to: T[], from: T[]): void {
         if (to && from) {
             for (const v of from) {
-                to.push(v);
+                if (v !== undefined) {
+                    to.push(v);
+                }
             }
         }
     }
@@ -278,15 +471,31 @@ namespace ts {
         return true;
     }
 
+    export function firstOrUndefined<T>(array: T[]): T {
+        return array && array.length > 0
+            ? array[0]
+            : undefined;
+    }
+
+    export function singleOrUndefined<T>(array: T[]): T {
+        return array && array.length === 1
+            ? array[0]
+            : undefined;
+    }
+
+    export function singleOrMany<T>(array: T[]): T | T[] {
+        return array && array.length === 1
+            ? array[0]
+            : array;
+    }
+
     /**
      * Returns the last element of an array if non-empty, undefined otherwise.
      */
     export function lastOrUndefined<T>(array: T[]): T {
-        if (array.length === 0) {
-            return undefined;
-        }
-
-        return array[array.length - 1];
+        return array && array.length > 0
+            ? array[array.length - 1]
+            : undefined;
     }
 
     /**
@@ -296,18 +505,25 @@ namespace ts {
      * @param array A sorted array whose first element must be no larger than number
      * @param number The value to be searched for in the array.
      */
-    export function binarySearch(array: number[], value: number): number {
+    export function binarySearch<T>(array: T[], value: T, comparer?: (v1: T, v2: T) => number): number {
+        if (!array || array.length === 0) {
+            return -1;
+        }
+
         let low = 0;
         let high = array.length - 1;
+        comparer = comparer !== undefined
+            ? comparer
+            : (v1, v2) => (v1 < v2 ? -1 : (v1 > v2 ? 1 : 0));
 
         while (low <= high) {
             const middle = low + ((high - low) >> 1);
             const midValue = array[middle];
 
-            if (midValue === value) {
+            if (comparer(midValue, value) === 0) {
                 return middle;
             }
-            else if (midValue > value) {
+            else if (comparer(midValue, value) > 0) {
                 high = middle - 1;
             }
             else {
@@ -318,14 +534,15 @@ namespace ts {
         return ~low;
     }
 
-    export function reduceLeft<T>(array: T[], f: (a: T, x: T) => T): T;
-    export function reduceLeft<T, U>(array: T[], f: (a: U, x: T) => U, initial: U): U;
-    export function reduceLeft<T, U>(array: T[], f: (a: U, x: T) => U, initial?: U): U {
-        if (array) {
-            const count = array.length;
-            if (count > 0) {
-                let pos = 0;
-                let result: T | U;
+    export function reduceLeft<T, U>(array: T[], f: (memo: U, value: T, i: number) => U, initial: U, start?: number, count?: number): U;
+    export function reduceLeft<T>(array: T[], f: (memo: T, value: T, i: number) => T): T;
+    export function reduceLeft<T>(array: T[], f: (memo: T, value: T, i: number) => T, initial?: T, start?: number, count?: number): T {
+        if (array && array.length > 0) {
+            const size = array.length;
+            if (size > 0) {
+                let pos = start === undefined || start < 0 ? 0 : start;
+                const end = count === undefined || pos + count > size - 1 ? size - 1 : pos + count;
+                let result: T;
                 if (arguments.length <= 2) {
                     result = array[pos];
                     pos++;
@@ -333,23 +550,25 @@ namespace ts {
                 else {
                     result = initial;
                 }
-                while (pos < count) {
-                    result = f(<U>result, array[pos]);
+                while (pos <= end) {
+                    result = f(result, array[pos], pos);
                     pos++;
                 }
-                return <U>result;
+                return result;
             }
         }
         return initial;
     }
 
-    export function reduceRight<T>(array: T[], f: (a: T, x: T) => T): T;
-    export function reduceRight<T, U>(array: T[], f: (a: U, x: T) => U, initial: U): U;
-    export function reduceRight<T, U>(array: T[], f: (a: U, x: T) => U, initial?: U): U {
+    export function reduceRight<T, U>(array: T[], f: (memo: U, value: T, i: number) => U, initial: U, start?: number, count?: number): U;
+    export function reduceRight<T>(array: T[], f: (memo: T, value: T, i: number) => T): T;
+    export function reduceRight<T>(array: T[], f: (memo: T, value: T, i: number) => T, initial?: T, start?: number, count?: number): T {
         if (array) {
-            let pos = array.length - 1;
-            if (pos >= 0) {
-                let result: T | U;
+            const size = array.length;
+            if (size > 0) {
+                let pos = start === undefined || start > size - 1 ? size - 1 : start;
+                const end = count === undefined || pos - count < 0 ? 0 : pos - count;
+                let result: T;
                 if (arguments.length <= 2) {
                     result = array[pos];
                     pos--;
@@ -357,11 +576,11 @@ namespace ts {
                 else {
                     result = initial;
                 }
-                while (pos >= 0) {
-                    result = f(<U>result, array[pos]);
+                while (pos >= end) {
+                    result = f(result, array[pos], pos);
                     pos--;
                 }
-                return <U>result;
+                return result;
             }
         }
         return initial;
@@ -450,6 +669,18 @@ namespace ts {
         }
     }
 
+    export function assign<T1 extends MapLike<{}>, T2, T3>(t: T1, arg1: T2, arg2: T3): T1 & T2 & T3;
+    export function assign<T1 extends MapLike<{}>, T2>(t: T1, arg1: T2): T1 & T2;
+    export function assign<T1 extends MapLike<{}>>(t: T1, ...args: any[]): any;
+    export function assign<T1 extends MapLike<{}>>(t: T1, ...args: any[]) {
+        for (const arg of args) {
+            for (const p of getOwnKeys(arg)) {
+                t[p] = arg[p];
+            }
+        }
+        return t;
+    }
+
     /**
      * Reduce the properties of a map.
      *
@@ -525,6 +756,15 @@ namespace ts {
         return result;
     }
 
+    export function isEmpty<T>(map: Map<T>) {
+        for (const id in map) {
+            if (hasProperty(map, id)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
     export function cloneMap<T>(map: Map<T>) {
         const clone = createMap<T>();
         copyProperties(map, clone);
@@ -552,6 +792,36 @@ namespace ts {
         return result;
     }
 
+    /**
+     * Adds the value to an array of values associated with the key, and returns the array.
+     * Creates the array if it does not already exist.
+     */
+    export function multiMapAdd<V>(map: Map<V[]>, key: string, value: V): V[] {
+        const values = map[key];
+        if (values) {
+            values.push(value);
+            return values;
+        }
+        else {
+            return map[key] = [value];
+        }
+    }
+
+    /**
+     * Removes a value from an array of values associated with the key.
+     * Does not preserve the order of those values.
+     * Does nothing if `key` is not in `map`, or `value` is not in `map[key]`.
+     */
+    export function multiMapRemove<V>(map: Map<V[]>, key: string, value: V): void {
+        const values = map[key];
+        if (values) {
+            unorderedRemoveItem(values, value);
+            if (!values.length) {
+                delete map[key];
+            }
+        }
+    }
+
     /**
      * Tests whether a value is an array.
      */
@@ -570,6 +840,72 @@ namespace ts {
         };
     }
 
+    /**
+     * High-order function, creates a function that executes a function composition.
+     * For example, `chain(a, b)` is the equivalent of `x => ((a', b') => y => b'(a'(y)))(a(x), b(x))`
+     *
+     * @param args The functions to chain.
+     */
+    export function chain<T, U>(...args: ((t: T) => (u: U) => U)[]): (t: T) => (u: U) => U;
+    export function chain<T, U>(a: (t: T) => (u: U) => U, b: (t: T) => (u: U) => U, c: (t: T) => (u: U) => U, d: (t: T) => (u: U) => U, e: (t: T) => (u: U) => U): (t: T) => (u: U) => U {
+        if (e) {
+            const args: ((t: T) => (u: U) => U)[] = [];
+            for (let i = 0; i < arguments.length; i++) {
+                args[i] = arguments[i];
+            }
+
+            return t => compose(...map(args, f => f(t)));
+        }
+        else if (d) {
+            return t => compose(a(t), b(t), c(t), d(t));
+        }
+        else if (c) {
+            return t => compose(a(t), b(t), c(t));
+        }
+        else if (b) {
+            return t => compose(a(t), b(t));
+        }
+        else if (a) {
+            return t => compose(a(t));
+        }
+        else {
+            return t => u => u;
+        }
+    }
+
+    /**
+     * High-order function, composes functions. Note that functions are composed inside-out;
+     * for example, `compose(a, b)` is the equivalent of `x => b(a(x))`.
+     *
+     * @param args The functions to compose.
+     */
+    export function compose<T>(...args: ((t: T) => T)[]): (t: T) => T;
+    export function compose<T>(a: (t: T) => T, b: (t: T) => T, c: (t: T) => T, d: (t: T) => T, e: (t: T) => T): (t: T) => T {
+        if (e) {
+            const args: ((t: T) => T)[] = [];
+            for (let i = 0; i < arguments.length; i++) {
+                args[i] = arguments[i];
+            }
+
+            return t => reduceLeft<(t: T) => T, T>(args, (u, f) => f(u), t);
+        }
+        else if (d) {
+            return t => d(c(b(a(t))));
+        }
+        else if (c) {
+            return t => c(b(a(t)));
+        }
+        else if (b) {
+            return t => b(a(t));
+        }
+        else if (a) {
+            return t => a(t);
+        }
+        else {
+            return t => t;
+        }
+    }
+
     function formatStringFromArgs(text: string, args: { [index: number]: any; }, baseIndex?: number): string {
         baseIndex = baseIndex || 0;
 
@@ -790,7 +1126,8 @@ namespace ts {
         return 0;
     }
 
-    export let directorySeparator = "/";
+    export const directorySeparator = "/";
+    const directorySeparatorCharCode = CharacterCodes.slash;
     function getNormalizedParts(normalizedSlashedPath: string, rootLength: number) {
         const parts = normalizedSlashedPath.substr(rootLength).split(directorySeparator);
         const normalized: string[] = [];
@@ -815,8 +1152,20 @@ namespace ts {
     export function normalizePath(path: string): string {
         path = normalizeSlashes(path);
         const rootLength = getRootLength(path);
+        const root = path.substr(0, rootLength);
         const normalized = getNormalizedParts(path, rootLength);
-        return path.substr(0, rootLength) + normalized.join(directorySeparator);
+        if (normalized.length) {
+            const joinedParts = root + normalized.join(directorySeparator);
+            return pathEndsWithDirectorySeparator(path) ? joinedParts + directorySeparator : joinedParts;
+        }
+        else {
+            return root;
+        }
+    }
+
+    /** A path ending with '/' refers to a directory only, never a file. */
+    export function pathEndsWithDirectorySeparator(path: string): boolean {
+        return path.charCodeAt(path.length - 1) === directorySeparatorCharCode;
     }
 
     export function getDirectoryPath(path: Path): Path;
@@ -829,10 +1178,49 @@ namespace ts {
         return path && !isRootedDiskPath(path) && path.indexOf("://") !== -1;
     }
 
+    export function isExternalModuleNameRelative(moduleName: string): boolean {
+        // TypeScript 1.0 spec (April 2014): 11.2.1
+        // An external module name is "relative" if the first term is "." or "..".
+        return /^\.\.?($|[\\/])/.test(moduleName);
+    }
+
+    export function getEmitScriptTarget(compilerOptions: CompilerOptions) {
+        return compilerOptions.target || ScriptTarget.ES3;
+    }
+
+    export function getEmitModuleKind(compilerOptions: CompilerOptions) {
+        return typeof compilerOptions.module === "number" ?
+            compilerOptions.module :
+            getEmitScriptTarget(compilerOptions) === ScriptTarget.ES6 ? ModuleKind.ES6 : ModuleKind.CommonJS;
+    }
+
+    /* @internal */
+    export function hasZeroOrOneAsteriskCharacter(str: string): boolean {
+        let seenAsterisk = false;
+        for (let i = 0; i < str.length; i++) {
+            if (str.charCodeAt(i) === CharacterCodes.asterisk) {
+                if (!seenAsterisk) {
+                    seenAsterisk = true;
+                }
+                else {
+                    // have already seen asterisk
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
     export function isRootedDiskPath(path: string) {
         return getRootLength(path) !== 0;
     }
 
+    export function convertToRelativePath(absoluteOrRelativePath: string, basePath: string, getCanonicalFileName: (path: string) => string): string {
+        return !isRootedDiskPath(absoluteOrRelativePath)
+            ? absoluteOrRelativePath
+            : getRelativePathToDirectoryOrUrl(basePath, absoluteOrRelativePath, basePath, getCanonicalFileName, /*isAbsolutePathAnUrl*/ false);
+    }
+
     function normalizedPathComponents(path: string, rootLength: number) {
         const normalizedParts = getNormalizedParts(path, rootLength);
         return [path.substr(0, rootLength)].concat(normalizedParts);
@@ -1315,6 +1703,8 @@ namespace ts {
      *  List of supported extensions in order of file resolution precedence.
      */
     export const supportedTypeScriptExtensions = [".ts", ".tsx", ".d.ts"];
+    /** Must have ".d.ts" first because if ".ts" goes first, that will be detected as the extension instead of ".d.ts". */
+    export const supportedTypescriptExtensionsForExtractExtension = [".d.ts", ".ts", ".tsx"];
     export const supportedJavascriptExtensions = [".js", ".jsx"];
     const allSupportedExtensions  = supportedTypeScriptExtensions.concat(supportedJavascriptExtensions);
 
@@ -1322,6 +1712,14 @@ namespace ts {
         return options && options.allowJs ? allSupportedExtensions : supportedTypeScriptExtensions;
     }
 
+    export function hasJavaScriptFileExtension(fileName: string) {
+        return forEach(supportedJavascriptExtensions, extension => fileExtensionIs(fileName, extension));
+    }
+
+    export function hasTypeScriptFileExtension(fileName: string) {
+        return forEach(supportedTypeScriptExtensions, extension => fileExtensionIs(fileName, extension));
+    }
+
     export function isSupportedSourceFileName(fileName: string, compilerOptions?: CompilerOptions) {
         if (!fileName) { return false; }
 
@@ -1397,8 +1795,12 @@ namespace ts {
         return path;
     }
 
-    export function tryRemoveExtension(path: string, extension: string): string {
-        return fileExtensionIs(path, extension) ? path.substring(0, path.length - extension.length) : undefined;
+    export function tryRemoveExtension(path: string, extension: string): string | undefined {
+        return fileExtensionIs(path, extension) ? removeExtension(path, extension) : undefined;
+    }
+
+    export function removeExtension(path: string, extension: string): string {
+        return path.substring(0, path.length - extension.length);
     }
 
     export function isJsxOrTsxExtension(ext: string): boolean {
@@ -1433,11 +1835,15 @@ namespace ts {
     }
 
     function Node(this: Node, kind: SyntaxKind, pos: number, end: number) {
+        this.id = 0;
         this.kind = kind;
         this.pos = pos;
         this.end = end;
         this.flags = NodeFlags.None;
+        this.modifierFlagsCache = ModifierFlags.None;
+        this.transformFlags = TransformFlags.None;
         this.parent = undefined;
+        this.original = undefined;
     }
 
     export let objectAllocator: ObjectAllocator = {
@@ -1458,10 +1864,13 @@ namespace ts {
     }
 
     export namespace Debug {
-        const currentAssertionLevel = AssertionLevel.None;
+        declare var process: any;
+        declare var require: any;
+
+        let currentAssertionLevel: AssertionLevel;
 
         export function shouldAssert(level: AssertionLevel): boolean {
-            return currentAssertionLevel >= level;
+            return getCurrentAssertionLevel() >= level;
         }
 
         export function assert(expression: boolean, message?: string, verboseDebugInfo?: () => string): void {
@@ -1478,22 +1887,148 @@ namespace ts {
         export function fail(message?: string): void {
             Debug.assert(/*expression*/ false, message);
         }
+
+        function getCurrentAssertionLevel() {
+            if (currentAssertionLevel !== undefined) {
+                return currentAssertionLevel;
+            }
+
+            if (sys === undefined) {
+                return AssertionLevel.None;
+            }
+
+            const developmentMode = /^development$/i.test(getEnvironmentVariable("NODE_ENV"));
+            currentAssertionLevel = developmentMode
+                ? AssertionLevel.Normal
+                : AssertionLevel.None;
+
+            return currentAssertionLevel;
+        }
     }
 
-    export function copyListRemovingItem<T>(item: T, list: T[]) {
-        const copiedList: T[] = [];
-        for (const e of list) {
-            if (e !== item) {
-                copiedList.push(e);
+    export function getEnvironmentVariable(name: string, host?: CompilerHost) {
+        if (host && host.getEnvironmentVariable) {
+            return host.getEnvironmentVariable(name);
+        }
+
+        if (sys && sys.getEnvironmentVariable) {
+            return sys.getEnvironmentVariable(name);
+        }
+
+        return "";
+    }
+
+    /** Remove an item from an array, moving everything to its right one space left. */
+    export function orderedRemoveItemAt<T>(array: T[], index: number): void {
+        // This seems to be faster than either `array.splice(i, 1)` or `array.copyWithin(i, i+ 1)`.
+        for (let i = index; i < array.length - 1; i++) {
+            array[i] = array[i + 1];
+        }
+        array.pop();
+    }
+
+    export function unorderedRemoveItemAt<T>(array: T[], index: number): void {
+        // Fill in the "hole" left at `index`.
+        array[index] = array[array.length - 1];
+        array.pop();
+    }
+
+    /** Remove the *first* occurrence of `item` from the array. */
+    export function unorderedRemoveItem<T>(array: T[], item: T): void {
+        unorderedRemoveFirstItemWhere(array, element => element === item);
+    }
+
+    /** Remove the *first* element satisfying `predicate`. */
+    function unorderedRemoveFirstItemWhere<T>(array: T[], predicate: (element: T) => boolean): void {
+        for (let i = 0; i < array.length; i++) {
+            if (predicate(array[i])) {
+                unorderedRemoveItemAt(array, i);
+                break;
             }
         }
-        return copiedList;
     }
 
-    export function createGetCanonicalFileName(useCaseSensitivefileNames: boolean): (fileName: string) => string {
-        return useCaseSensitivefileNames
+    export function createGetCanonicalFileName(useCaseSensitiveFileNames: boolean): (fileName: string) => string {
+        return useCaseSensitiveFileNames
             ? ((fileName) => fileName)
             : ((fileName) => fileName.toLowerCase());
     }
 
+    /**
+     * patternStrings contains both pattern strings (containing "*") and regular strings.
+     * Return an exact match if possible, or a pattern match, or undefined.
+     * (These are verified by verifyCompilerOptions to have 0 or 1 "*" characters.)
+     */
+    /* @internal */
+    export function matchPatternOrExact(patternStrings: string[], candidate: string): string | Pattern | undefined {
+        const patterns: Pattern[] = [];
+        for (const patternString of patternStrings) {
+            const pattern = tryParsePattern(patternString);
+            if (pattern) {
+                patterns.push(pattern);
+            }
+            else if (patternString === candidate) {
+                // pattern was matched as is - no need to search further
+                return patternString;
+            }
+        }
+
+        return findBestPatternMatch(patterns, _ => _, candidate);
+    }
+
+    /* @internal */
+    export function patternText({prefix, suffix}: Pattern): string {
+        return `${prefix}*${suffix}`;
+    }
+
+    /**
+     * Given that candidate matches pattern, returns the text matching the '*'.
+     * E.g.: matchedText(tryParsePattern("foo*baz"), "foobarbaz") === "bar"
+     */
+    /* @internal */
+    export function matchedText(pattern: Pattern, candidate: string): string {
+        Debug.assert(isPatternMatch(pattern, candidate));
+        return candidate.substr(pattern.prefix.length, candidate.length - pattern.suffix.length);
+    }
+
+    /** Return the object corresponding to the best pattern to match `candidate`. */
+    /* @internal */
+    export function findBestPatternMatch<T>(values: T[], getPattern: (value: T) => Pattern, candidate: string): T | undefined {
+        let matchedValue: T | undefined = undefined;
+        // use length of prefix as betterness criteria
+        let longestMatchPrefixLength = -1;
+
+        for (const v of values) {
+            const pattern = getPattern(v);
+            if (isPatternMatch(pattern, candidate) && pattern.prefix.length > longestMatchPrefixLength) {
+                longestMatchPrefixLength = pattern.prefix.length;
+                matchedValue = v;
+            }
+        }
+
+        return matchedValue;
+    }
+
+    function isPatternMatch({prefix, suffix}: Pattern, candidate: string) {
+        return candidate.length >= prefix.length + suffix.length &&
+            startsWith(candidate, prefix) &&
+            endsWith(candidate, suffix);
+    }
+
+    /* @internal */
+    export function tryParsePattern(pattern: string): Pattern | undefined {
+        // This should be verified outside of here and a proper error thrown.
+        Debug.assert(hasZeroOrOneAsteriskCharacter(pattern));
+        const indexOfStar = pattern.indexOf("*");
+        return indexOfStar === -1 ? undefined : {
+            prefix: pattern.substr(0, indexOfStar),
+            suffix: pattern.substr(indexOfStar + 1)
+        };
+    }
+
+    export function positionIsSynthesized(pos: number): boolean {
+        // This is a fast way of testing the following conditions:
+        //  pos === undefined || pos === null || isNaN(pos) || pos < 0;
+        return !(pos >= 0);
+    }
 }

src/compiler/declarationEmitter.ts

@@ -36,12 +36,12 @@ namespace ts {
         return declarationDiagnostics.getDiagnostics(targetSourceFile ? targetSourceFile.fileName : undefined);
 
         function getDeclarationDiagnosticsFromFile({ declarationFilePath }: EmitFileNames, sources: SourceFile[], isBundledEmit: boolean) {
-            emitDeclarations(host, resolver, declarationDiagnostics, declarationFilePath, sources, isBundledEmit);
+            emitDeclarations(host, resolver, declarationDiagnostics, declarationFilePath, sources, isBundledEmit, /*emitOnlyDtsFiles*/ false);
         }
     }
 
     function emitDeclarations(host: EmitHost, resolver: EmitResolver, emitterDiagnostics: DiagnosticCollection, declarationFilePath: string,
-        sourceFiles: SourceFile[], isBundledEmit: boolean): DeclarationEmit {
+        sourceFiles: SourceFile[], isBundledEmit: boolean, emitOnlyDtsFiles: boolean): DeclarationEmit {
         const newLine = host.getNewLine();
         const compilerOptions = host.getCompilerOptions();
 
@@ -98,7 +98,7 @@ namespace ts {
                         // global file reference is added only
                         //  - if it is not bundled emit (because otherwise it would be self reference)
                         //  - and it is not already added
-                        if (writeReferencePath(referencedFile, !isBundledEmit && !addedGlobalFileReference)) {
+                        if (writeReferencePath(referencedFile, !isBundledEmit && !addedGlobalFileReference, emitOnlyDtsFiles)) {
                             addedGlobalFileReference = true;
                         }
                         emittedReferencedFiles.push(referencedFile);
@@ -306,7 +306,7 @@ namespace ts {
         }
 
         function trackSymbol(symbol: Symbol, enclosingDeclaration?: Node, meaning?: SymbolFlags) {
-            handleSymbolAccessibilityError(resolver.isSymbolAccessible(symbol, enclosingDeclaration, meaning));
+            handleSymbolAccessibilityError(resolver.isSymbolAccessible(symbol, enclosingDeclaration, meaning, /*shouldComputeAliasesToMakeVisible*/ true));
             recordTypeReferenceDirectivesIfNecessary(resolver.getTypeReferenceDirectivesForSymbol(symbol, meaning));
         }
 
@@ -327,7 +327,7 @@ namespace ts {
             }
             else {
                 errorNameNode = declaration.name;
-                resolver.writeTypeOfDeclaration(declaration, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction, writer);
+                resolver.writeTypeOfDeclaration(declaration, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue, writer);
                 errorNameNode = undefined;
             }
         }
@@ -341,7 +341,7 @@ namespace ts {
             }
             else {
                 errorNameNode = signature.name;
-                resolver.writeReturnTypeOfSignatureDeclaration(signature, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction, writer);
+                resolver.writeReturnTypeOfSignatureDeclaration(signature, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue, writer);
                 errorNameNode = undefined;
             }
         }
@@ -374,7 +374,7 @@ namespace ts {
                 const jsDocComments = getJsDocCommentsFromText(declaration, currentText);
                 emitNewLineBeforeLeadingComments(currentLineMap, writer, declaration, jsDocComments);
                 // jsDoc comments are emitted at /*leading comment1 */space/*leading comment*/space
-                emitComments(currentText, currentLineMap, writer, jsDocComments, /*trailingSeparator*/ true, newLine, writeCommentRange);
+                emitComments(currentText, currentLineMap, writer, jsDocComments, /*leadingSeparator*/ false, /*trailingSeparator*/ true, newLine, writeCommentRange);
             }
         }
 
@@ -563,7 +563,7 @@ namespace ts {
                 write(tempVarName);
                 write(": ");
                 writer.getSymbolAccessibilityDiagnostic = getDefaultExportAccessibilityDiagnostic;
-                resolver.writeTypeOfExpression(node.expression, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction, writer);
+                resolver.writeTypeOfExpression(node.expression, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue, writer);
                 write(";");
                 writeLine();
                 write(node.isExportEquals ? "export = " : "export default ");
@@ -655,12 +655,13 @@ namespace ts {
         function emitModuleElementDeclarationFlags(node: Node) {
             // If the node is parented in the current source file we need to emit export declare or just export
             if (node.parent.kind === SyntaxKind.SourceFile) {
+                const modifiers = getModifierFlags(node);
                 // If the node is exported
-                if (node.flags & NodeFlags.Export) {
+                if (modifiers & ModifierFlags.Export) {
                     write("export ");
                 }
 
-                if (node.flags & NodeFlags.Default) {
+                if (modifiers & ModifierFlags.Default) {
                     write("default ");
                 }
                 else if (node.kind !== SyntaxKind.InterfaceDeclaration && !noDeclare) {
@@ -669,21 +670,21 @@ namespace ts {
             }
         }
 
-        function emitClassMemberDeclarationFlags(flags: NodeFlags) {
-            if (flags & NodeFlags.Private) {
+        function emitClassMemberDeclarationFlags(flags: ModifierFlags) {
+            if (flags & ModifierFlags.Private) {
                 write("private ");
             }
-            else if (flags & NodeFlags.Protected) {
+            else if (flags & ModifierFlags.Protected) {
                 write("protected ");
             }
 
-            if (flags & NodeFlags.Static) {
+            if (flags & ModifierFlags.Static) {
                 write("static ");
             }
-            if (flags & NodeFlags.Readonly) {
+            if (flags & ModifierFlags.Readonly) {
                 write("readonly ");
             }
-            if (flags & NodeFlags.Abstract) {
+            if (flags & ModifierFlags.Abstract) {
                 write("abstract ");
             }
         }
@@ -692,7 +693,7 @@ namespace ts {
             // note usage of writer. methods instead of aliases created, just to make sure we are using
             // correct writer especially to handle asynchronous alias writing
             emitJsDocComments(node);
-            if (node.flags & NodeFlags.Export) {
+            if (hasModifier(node, ModifierFlags.Export)) {
                 write("export ");
             }
             write("import ");
@@ -731,7 +732,7 @@ namespace ts {
 
         function writeImportDeclaration(node: ImportDeclaration) {
             emitJsDocComments(node);
-            if (node.flags & NodeFlags.Export) {
+            if (hasModifier(node, ModifierFlags.Export)) {
                 write("export ");
             }
             write("import ");
@@ -926,7 +927,7 @@ namespace ts {
         }
 
         function isPrivateMethodTypeParameter(node: TypeParameterDeclaration) {
-            return node.parent.kind === SyntaxKind.MethodDeclaration && (node.parent.flags & NodeFlags.Private);
+            return node.parent.kind === SyntaxKind.MethodDeclaration && hasModifier(node.parent, ModifierFlags.Private);
         }
 
         function emitTypeParameters(typeParameters: TypeParameterDeclaration[]) {
@@ -976,7 +977,7 @@ namespace ts {
 
                         case SyntaxKind.MethodDeclaration:
                         case SyntaxKind.MethodSignature:
-                            if (node.parent.flags & NodeFlags.Static) {
+                            if (hasModifier(node.parent, ModifierFlags.Static)) {
                                 diagnosticMessage = Diagnostics.Type_parameter_0_of_public_static_method_from_exported_class_has_or_is_using_private_name_1;
                             }
                             else if (node.parent.parent.kind === SyntaxKind.ClassDeclaration) {
@@ -1025,7 +1026,7 @@ namespace ts {
                 }
                 else {
                     writer.getSymbolAccessibilityDiagnostic = getHeritageClauseVisibilityError;
-                    resolver.writeBaseConstructorTypeOfClass(<ClassLikeDeclaration>enclosingDeclaration, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction, writer);
+                    resolver.writeBaseConstructorTypeOfClass(<ClassLikeDeclaration>enclosingDeclaration, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue, writer);
                 }
 
                 function getHeritageClauseVisibilityError(symbolAccessibilityResult: SymbolAccessibilityResult): SymbolAccessibilityDiagnostic {
@@ -1055,7 +1056,7 @@ namespace ts {
             function emitParameterProperties(constructorDeclaration: ConstructorDeclaration) {
                 if (constructorDeclaration) {
                     forEach(constructorDeclaration.parameters, param => {
-                        if (param.flags & NodeFlags.ParameterPropertyModifier) {
+                        if (hasModifier(param, ModifierFlags.ParameterPropertyModifier)) {
                             emitPropertyDeclaration(param);
                         }
                     });
@@ -1064,7 +1065,7 @@ namespace ts {
 
             emitJsDocComments(node);
             emitModuleElementDeclarationFlags(node);
-            if (node.flags & NodeFlags.Abstract) {
+            if (hasModifier(node, ModifierFlags.Abstract)) {
                 write("abstract ");
             }
 
@@ -1114,7 +1115,7 @@ namespace ts {
             }
 
             emitJsDocComments(node);
-            emitClassMemberDeclarationFlags(node.flags);
+            emitClassMemberDeclarationFlags(getModifierFlags(node));
             emitVariableDeclaration(<VariableDeclaration>node);
             write(";");
             writeLine();
@@ -1132,14 +1133,20 @@ namespace ts {
                     // it if it's not a well known symbol. In that case, the text of the name will be exactly
                     // what we want, namely the name expression enclosed in brackets.
                     writeTextOfNode(currentText, node.name);
-                    // If optional property emit ?
-                    if ((node.kind === SyntaxKind.PropertyDeclaration || node.kind === SyntaxKind.PropertySignature || node.kind === SyntaxKind.Parameter) && hasQuestionToken(node)) {
+                    // If optional property emit ? but in the case of parameterProperty declaration with "?" indicating optional parameter for the constructor
+                    // we don't want to emit property declaration with "?"
+                    if ((node.kind === SyntaxKind.PropertyDeclaration || node.kind === SyntaxKind.PropertySignature ||
+                        (node.kind === SyntaxKind.Parameter && !isParameterPropertyDeclaration(node))) && hasQuestionToken(node)) {
                         write("?");
                     }
                     if ((node.kind === SyntaxKind.PropertyDeclaration || node.kind === SyntaxKind.PropertySignature) && node.parent.kind === SyntaxKind.TypeLiteral) {
                         emitTypeOfVariableDeclarationFromTypeLiteral(node);
                     }
-                    else if (!(node.flags & NodeFlags.Private)) {
+                    else if (resolver.isLiteralConstDeclaration(node)) {
+                        write(" = ");
+                        resolver.writeLiteralConstValue(node, writer);
+                    }
+                    else if (!hasModifier(node, ModifierFlags.Private)) {
                         writeTypeOfDeclaration(node, node.type, getVariableDeclarationTypeVisibilityError);
                     }
                 }
@@ -1156,7 +1163,7 @@ namespace ts {
                 // This check is to ensure we don't report error on constructor parameter property as that error would be reported during parameter emit
                 else if (node.kind === SyntaxKind.PropertyDeclaration || node.kind === SyntaxKind.PropertySignature) {
                     // TODO(jfreeman): Deal with computed properties in error reporting.
-                    if (node.flags & NodeFlags.Static) {
+                    if (hasModifier(node, ModifierFlags.Static)) {
                         return symbolAccessibilityResult.errorModuleName ?
                             symbolAccessibilityResult.accessibility === SymbolAccessibility.CannotBeNamed ?
                                 Diagnostics.Public_static_property_0_of_exported_class_has_or_is_using_name_1_from_external_module_2_but_cannot_be_named :
@@ -1267,9 +1274,9 @@ namespace ts {
             if (node === accessors.firstAccessor) {
                 emitJsDocComments(accessors.getAccessor);
                 emitJsDocComments(accessors.setAccessor);
-                emitClassMemberDeclarationFlags(node.flags | (accessors.setAccessor ? 0 : NodeFlags.Readonly));
+                emitClassMemberDeclarationFlags(getModifierFlags(node) | (accessors.setAccessor ? 0 : ModifierFlags.Readonly));
                 writeTextOfNode(currentText, node.name);
-                if (!(node.flags & NodeFlags.Private)) {
+                if (!hasModifier(node, ModifierFlags.Private)) {
                     accessorWithTypeAnnotation = node;
                     let type = getTypeAnnotationFromAccessor(node);
                     if (!type) {
@@ -1300,7 +1307,7 @@ namespace ts {
                 let diagnosticMessage: DiagnosticMessage;
                 if (accessorWithTypeAnnotation.kind === SyntaxKind.SetAccessor) {
                     // Setters have to have type named and cannot infer it so, the type should always be named
-                    if (accessorWithTypeAnnotation.parent.flags & NodeFlags.Static) {
+                    if (hasModifier(accessorWithTypeAnnotation.parent, ModifierFlags.Static)) {
                         diagnosticMessage = symbolAccessibilityResult.errorModuleName ?
                             Diagnostics.Parameter_0_of_public_static_property_setter_from_exported_class_has_or_is_using_name_1_from_private_module_2 :
                             Diagnostics.Parameter_0_of_public_static_property_setter_from_exported_class_has_or_is_using_private_name_1;
@@ -1318,7 +1325,7 @@ namespace ts {
                     };
                 }
                 else {
-                    if (accessorWithTypeAnnotation.flags & NodeFlags.Static) {
+                    if (hasModifier(accessorWithTypeAnnotation, ModifierFlags.Static)) {
                         diagnosticMessage = symbolAccessibilityResult.errorModuleName ?
                             symbolAccessibilityResult.accessibility === SymbolAccessibility.CannotBeNamed ?
                                 Diagnostics.Return_type_of_public_static_property_getter_from_exported_class_has_or_is_using_name_0_from_external_module_1_but_cannot_be_named :
@@ -1354,7 +1361,7 @@ namespace ts {
                     emitModuleElementDeclarationFlags(node);
                 }
                 else if (node.kind === SyntaxKind.MethodDeclaration || node.kind === SyntaxKind.Constructor) {
-                    emitClassMemberDeclarationFlags(node.flags);
+                    emitClassMemberDeclarationFlags(getModifierFlags(node));
                 }
                 if (node.kind === SyntaxKind.FunctionDeclaration) {
                     write("function ");
@@ -1385,7 +1392,7 @@ namespace ts {
 
             if (node.kind === SyntaxKind.IndexSignature) {
                 // Index signature can have readonly modifier
-                emitClassMemberDeclarationFlags(node.flags);
+                emitClassMemberDeclarationFlags(getModifierFlags(node));
                 write("[");
             }
             else {
@@ -1426,7 +1433,7 @@ namespace ts {
                     emitType(node.type);
                 }
             }
-            else if (node.kind !== SyntaxKind.Constructor && !(node.flags & NodeFlags.Private)) {
+            else if (node.kind !== SyntaxKind.Constructor && !hasModifier(node, ModifierFlags.Private)) {
                 writeReturnTypeAtSignature(node, getReturnTypeVisibilityError);
             }
 
@@ -1466,7 +1473,7 @@ namespace ts {
 
                     case SyntaxKind.MethodDeclaration:
                     case SyntaxKind.MethodSignature:
-                        if (node.flags & NodeFlags.Static) {
+                        if (hasModifier(node, ModifierFlags.Static)) {
                             diagnosticMessage = symbolAccessibilityResult.errorModuleName ?
                                 symbolAccessibilityResult.accessibility === SymbolAccessibility.CannotBeNamed ?
                                     Diagnostics.Return_type_of_public_static_method_from_exported_class_has_or_is_using_name_0_from_external_module_1_but_cannot_be_named :
@@ -1532,7 +1539,7 @@ namespace ts {
                 node.parent.parent.kind === SyntaxKind.TypeLiteral) {
                 emitTypeOfVariableDeclarationFromTypeLiteral(node);
             }
-            else if (!(node.parent.flags & NodeFlags.Private)) {
+            else if (!hasModifier(node.parent, ModifierFlags.Private)) {
                 writeTypeOfDeclaration(node, node.type, getParameterDeclarationTypeVisibilityError);
             }
 
@@ -1568,7 +1575,7 @@ namespace ts {
 
                     case SyntaxKind.MethodDeclaration:
                     case SyntaxKind.MethodSignature:
-                        if (node.parent.flags & NodeFlags.Static) {
+                        if (hasModifier(node.parent, ModifierFlags.Static)) {
                             return symbolAccessibilityResult.errorModuleName ?
                                 symbolAccessibilityResult.accessibility === SymbolAccessibility.CannotBeNamed ?
                                     Diagnostics.Parameter_0_of_public_static_method_from_exported_class_has_or_is_using_name_1_from_external_module_2_but_cannot_be_named :
@@ -1713,7 +1720,7 @@ namespace ts {
          * @param referencedFile
          * @param addBundledFileReference Determines if global file reference corresponding to bundled file should be emitted or not
          */
-        function writeReferencePath(referencedFile: SourceFile, addBundledFileReference: boolean): boolean {
+        function writeReferencePath(referencedFile: SourceFile, addBundledFileReference: boolean, emitOnlyDtsFiles: boolean): boolean {
             let declFileName: string;
             let addedBundledEmitReference = false;
             if (isDeclarationFile(referencedFile)) {
@@ -1722,7 +1729,7 @@ namespace ts {
             }
             else {
                 // Get the declaration file path
-                forEachExpectedEmitFile(host, getDeclFileName, referencedFile);
+                forEachExpectedEmitFile(host, getDeclFileName, referencedFile, emitOnlyDtsFiles);
             }
 
             if (declFileName) {
@@ -1751,8 +1758,8 @@ namespace ts {
     }
 
     /* @internal */
-    export function writeDeclarationFile(declarationFilePath: string, sourceFiles: SourceFile[], isBundledEmit: boolean, host: EmitHost, resolver: EmitResolver, emitterDiagnostics: DiagnosticCollection) {
-        const emitDeclarationResult = emitDeclarations(host, resolver, emitterDiagnostics, declarationFilePath, sourceFiles, isBundledEmit);
+    export function writeDeclarationFile(declarationFilePath: string, sourceFiles: SourceFile[], isBundledEmit: boolean, host: EmitHost, resolver: EmitResolver, emitterDiagnostics: DiagnosticCollection, emitOnlyDtsFiles: boolean) {
+        const emitDeclarationResult = emitDeclarations(host, resolver, emitterDiagnostics, declarationFilePath, sourceFiles, isBundledEmit, emitOnlyDtsFiles);
         const emitSkipped = emitDeclarationResult.reportedDeclarationError || host.isEmitBlocked(declarationFilePath) || host.getCompilerOptions().noEmit;
         if (!emitSkipped) {
             const declarationOutput = emitDeclarationResult.referencesOutput

src/compiler/diagnosticMessages.json

@@ -819,6 +819,10 @@
         "category": "Error",
         "code": 1253
     },
+    "A 'const' initializer in an ambient context must be a string or numeric literal.": {
+        "category": "Error",
+        "code": 1254
+    },
     "'with' statements are not allowed in an async function block.": {
         "category": "Error",
         "code": 1300
@@ -827,10 +831,6 @@
         "category": "Error",
         "code": 1308
     },
-    "Async functions are only available when targeting ECMAScript 2015 or higher.": {
-        "category": "Error",
-        "code": 1311
-    },
     "'=' can only be used in an object literal property inside a destructuring assignment.": {
         "category": "Error",
         "code": 1312
@@ -1047,7 +1047,7 @@
         "category": "Error",
         "code": 2348
     },
-    "Cannot invoke an expression whose type lacks a call signature.": {
+    "Cannot invoke an expression whose type lacks a call signature. Type '{0}' has no compatible call signatures.": {
         "category": "Error",
         "code": 2349
     },
@@ -1067,10 +1067,6 @@
         "category": "Error",
         "code": 2353
     },
-    "No best common type exists among return expressions.": {
-        "category": "Error",
-        "code": 2354
-    },
     "A function whose declared type is neither 'void' nor 'any' must return a value.": {
         "category": "Error",
         "code": 2355
@@ -1283,7 +1279,7 @@
         "category": "Error",
         "code": 2409
     },
-    "All symbols within a 'with' block will be resolved to 'any'.": {
+    "The 'with' statement is not supported. All symbols in a 'with' block will have type 'any'.": {
         "category": "Error",
         "code": 2410
     },
@@ -1635,10 +1631,6 @@
         "category": "Error",
         "code": 2503
     },
-    "No best common type exists among yield expressions.": {
-        "category": "Error",
-        "code": 2504
-    },
     "A generator cannot have a 'void' type annotation.": {
         "category": "Error",
         "code": 2505
@@ -1703,7 +1695,7 @@
         "category": "Error",
         "code": 2521
     },
-    "The 'arguments' object cannot be referenced in an async arrow function. Consider using a standard async function expression.": {
+    "The 'arguments' object cannot be referenced in an async function or method in ES3 and ES5. Consider using a standard function or method.": {
         "category": "Error",
         "code": 2522
     },
@@ -1951,6 +1943,31 @@
         "category": "Error",
         "code": 2690
     },
+    "An import path cannot end with a '{0}' extension. Consider importing '{1}' instead.": {
+        "category": "Error",
+        "code": 2691
+    },
+    "'{0}' is a primitive, but '{1}' is a wrapper object. Prefer using '{0}' when possible.": {
+        "category": "Error",
+        "code": 2692
+    },
+    "'{0}' only refers to a type, but is being used as a value here.": {
+        "category": "Error",
+        "code": 2693
+    },
+    "Namespace '{0}' has no exported member '{1}'.": {
+        "category": "Error",
+        "code": 2694
+    },
+    "Left side of comma operator is unused and has no side effects.": {
+        "category": "Error",
+        "code": 2695
+    },
+    "The 'Object' type is assignable to very few other types. Did you mean to use the 'any' type instead?": {
+        "category": "Error",
+        "code": 2696
+    },
+
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
         "code": 4000
@@ -2468,6 +2485,10 @@
         "category": "Message",
         "code": 6038
     },
+    "STRATEGY": {
+        "category": "Message",
+        "code": 6039
+    },
     "Compilation complete. Watching for file changes.": {
         "category": "Message",
         "code": 6042
@@ -2832,6 +2853,14 @@
         "category": "Error",
         "code": 6138
     },
+    "Import emit helpers from 'tslib'.": {
+        "category": "Message",
+        "code": 6139
+    },
+    "Auto discovery for typings is enabled in project '{0}'. Running extra resolution pass for module '{1}' using cache location '{2}'.": {
+        "category": "Error",
+        "code": 6140
+    },
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",
         "code": 7005
@@ -2864,10 +2893,6 @@
         "category": "Error",
         "code": 7015
     },
-    "Property '{0}' implicitly has type 'any', because its 'set' accessor lacks a type annotation.": {
-        "category": "Error",
-        "code": 7016
-    },
     "Index signature of object type implicitly has an 'any' type.": {
         "category": "Error",
         "code": 7017
@@ -2924,6 +2949,14 @@
         "category": "Error",
         "code": 7031
     },
+    "Property '{0}' implicitly has type 'any', because its set accessor lacks a parameter type annotation.": {
+        "category": "Error",
+        "code": 7032
+    },
+    "Property '{0}' implicitly has type 'any', because its get accessor lacks a return type annotation.": {
+        "category": "Error",
+        "code": 7033
+    },
     "You cannot rename this element.": {
         "category": "Error",
         "code": 8000
@@ -3035,5 +3068,14 @@
     "Unknown typing option '{0}'.": {
         "category": "Error",
         "code": 17010
+    },
+
+    "Circularity detected while resolving configuration: {0}": {
+        "category": "Error",
+        "code": 18000
+    },
+    "The path in an 'extends' options must be relative or rooted.": {
+        "category": "Error",
+        "code": 18001
     }
 }

src/compiler/moduleNameResolver.ts

@@ -0,0 +1,744 @@
+/// <reference path="core.ts" />
+/// <reference path="diagnosticInformationMap.generated.ts" />
+
+namespace ts {
+
+    /* @internal */
+    export function trace(host: ModuleResolutionHost, message: DiagnosticMessage, ...args: any[]): void;
+    export function trace(host: ModuleResolutionHost, message: DiagnosticMessage): void {
+        host.trace(formatMessage.apply(undefined, arguments));
+    }
+
+    /* @internal */
+    export function isTraceEnabled(compilerOptions: CompilerOptions, host: ModuleResolutionHost): boolean {
+        return compilerOptions.traceResolution && host.trace !== undefined;
+    }
+
+    /* @internal */
+    export function createResolvedModule(resolvedFileName: string, isExternalLibraryImport: boolean, failedLookupLocations: string[]): ResolvedModuleWithFailedLookupLocations {
+        return { resolvedModule: resolvedFileName ? { resolvedFileName, isExternalLibraryImport } : undefined, failedLookupLocations };
+    }
+
+    function moduleHasNonRelativeName(moduleName: string): boolean {
+        return !(isRootedDiskPath(moduleName) || isExternalModuleNameRelative(moduleName));
+    }
+
+    /* @internal */
+    export interface ModuleResolutionState {
+        host: ModuleResolutionHost;
+        compilerOptions: CompilerOptions;
+        traceEnabled: boolean;
+        // skip .tsx files if jsx is not enabled
+        skipTsx: boolean;
+    }
+
+    function tryReadTypesSection(packageJsonPath: string, baseDirectory: string, state: ModuleResolutionState): string {
+        const jsonContent = readJson(packageJsonPath, state.host);
+
+        function tryReadFromField(fieldName: string) {
+            if (hasProperty(jsonContent, fieldName)) {
+                const typesFile = (<any>jsonContent)[fieldName];
+                if (typeof typesFile === "string") {
+                    const typesFilePath = normalizePath(combinePaths(baseDirectory, typesFile));
+                    if (state.traceEnabled) {
+                        trace(state.host, Diagnostics.package_json_has_0_field_1_that_references_2, fieldName, typesFile, typesFilePath);
+                    }
+                    return typesFilePath;
+                }
+                else {
+                    if (state.traceEnabled) {
+                        trace(state.host, Diagnostics.Expected_type_of_0_field_in_package_json_to_be_string_got_1, fieldName, typeof typesFile);
+                    }
+                }
+            }
+        }
+
+        const typesFilePath = tryReadFromField("typings") || tryReadFromField("types");
+        if (typesFilePath) {
+            return typesFilePath;
+        }
+
+        // Use the main module for inferring types if no types package specified and the allowJs is set
+        if (state.compilerOptions.allowJs && jsonContent.main && typeof jsonContent.main === "string") {
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.No_types_specified_in_package_json_but_allowJs_is_set_so_returning_main_value_of_0, jsonContent.main);
+            }
+            const mainFilePath = normalizePath(combinePaths(baseDirectory, jsonContent.main));
+            return mainFilePath;
+        }
+        return undefined;
+    }
+
+    function readJson(path: string, host: ModuleResolutionHost): { typings?: string, types?: string, main?: string } {
+        try {
+            const jsonText = host.readFile(path);
+            return jsonText ? JSON.parse(jsonText) : {};
+        }
+        catch (e) {
+            // gracefully handle if readFile fails or returns not JSON
+            return {};
+        }
+    }
+
+    const typeReferenceExtensions = [".d.ts"];
+
+    export function getEffectiveTypeRoots(options: CompilerOptions, host: { directoryExists?: (directoryName: string) => boolean, getCurrentDirectory?: () => string }): string[] | undefined {
+        if (options.typeRoots) {
+            return options.typeRoots;
+        }
+
+        let currentDirectory: string;
+        if (options.configFilePath) {
+            currentDirectory = getDirectoryPath(options.configFilePath);
+        }
+        else if (host.getCurrentDirectory) {
+            currentDirectory = host.getCurrentDirectory();
+        }
+
+        return currentDirectory && getDefaultTypeRoots(currentDirectory, host);
+    }
+
+    /**
+     * Returns the path to every node_modules/@types directory from some ancestor directory.
+     * Returns undefined if there are none.
+     */
+    function getDefaultTypeRoots(currentDirectory: string, host: { directoryExists?: (directoryName: string) => boolean }): string[] | undefined {
+        if (!host.directoryExists) {
+            return [combinePaths(currentDirectory, nodeModulesAtTypes)];
+            // And if it doesn't exist, tough.
+        }
+
+        let typeRoots: string[];
+
+        while (true) {
+            const atTypes = combinePaths(currentDirectory, nodeModulesAtTypes);
+            if (host.directoryExists(atTypes)) {
+                (typeRoots || (typeRoots = [])).push(atTypes);
+            }
+
+            const parent = getDirectoryPath(currentDirectory);
+            if (parent === currentDirectory) {
+                break;
+            }
+            currentDirectory = parent;
+        }
+
+        return typeRoots;
+    }
+    const nodeModulesAtTypes = combinePaths("node_modules", "@types");
+
+    /**
+     * @param {string | undefined} containingFile - file that contains type reference directive, can be undefined if containing file is unknown.
+     * This is possible in case if resolution is performed for directives specified via 'types' parameter. In this case initial path for secondary lookups
+     * is assumed to be the same as root directory of the project.
+     */
+    export function resolveTypeReferenceDirective(typeReferenceDirectiveName: string, containingFile: string, options: CompilerOptions, host: ModuleResolutionHost): ResolvedTypeReferenceDirectiveWithFailedLookupLocations {
+        const traceEnabled = isTraceEnabled(options, host);
+        const moduleResolutionState: ModuleResolutionState = {
+            compilerOptions: options,
+            host: host,
+            skipTsx: true,
+            traceEnabled
+        };
+
+        const typeRoots = getEffectiveTypeRoots(options, host);
+        if (traceEnabled) {
+            if (containingFile === undefined) {
+                if (typeRoots === undefined) {
+                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_not_set_root_directory_not_set, typeReferenceDirectiveName);
+                }
+                else {
+                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_not_set_root_directory_1, typeReferenceDirectiveName, typeRoots);
+                }
+            }
+            else {
+                if (typeRoots === undefined) {
+                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_1_root_directory_not_set, typeReferenceDirectiveName, containingFile);
+                }
+                else {
+                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_1_root_directory_2, typeReferenceDirectiveName, containingFile, typeRoots);
+                }
+            }
+        }
+
+        const failedLookupLocations: string[] = [];
+
+        // Check primary library paths
+        if (typeRoots && typeRoots.length) {
+            if (traceEnabled) {
+                trace(host, Diagnostics.Resolving_with_primary_search_path_0, typeRoots.join(", "));
+            }
+            const primarySearchPaths = typeRoots;
+            for (const typeRoot of primarySearchPaths) {
+                const candidate = combinePaths(typeRoot, typeReferenceDirectiveName);
+                const candidateDirectory = getDirectoryPath(candidate);
+                const resolvedFile = loadNodeModuleFromDirectory(typeReferenceExtensions, candidate, failedLookupLocations,
+                    !directoryProbablyExists(candidateDirectory, host), moduleResolutionState);
+
+                if (resolvedFile) {
+                    if (traceEnabled) {
+                        trace(host, Diagnostics.Type_reference_directive_0_was_successfully_resolved_to_1_primary_Colon_2, typeReferenceDirectiveName, resolvedFile, true);
+                    }
+                    return {
+                        resolvedTypeReferenceDirective: { primary: true, resolvedFileName: resolvedFile },
+                        failedLookupLocations
+                    };
+                }
+            }
+        }
+        else {
+            if (traceEnabled) {
+                trace(host, Diagnostics.Root_directory_cannot_be_determined_skipping_primary_search_paths);
+            }
+        }
+
+        let resolvedFile: string;
+        let initialLocationForSecondaryLookup: string;
+        if (containingFile) {
+            initialLocationForSecondaryLookup = getDirectoryPath(containingFile);
+        }
+
+        if (initialLocationForSecondaryLookup !== undefined) {
+            // check secondary locations
+            if (traceEnabled) {
+                trace(host, Diagnostics.Looking_up_in_node_modules_folder_initial_location_0, initialLocationForSecondaryLookup);
+            }
+            resolvedFile = loadModuleFromNodeModules(typeReferenceDirectiveName, initialLocationForSecondaryLookup, failedLookupLocations, moduleResolutionState, /*checkOneLevel*/ false);
+            if (traceEnabled) {
+                if (resolvedFile) {
+                    trace(host, Diagnostics.Type_reference_directive_0_was_successfully_resolved_to_1_primary_Colon_2, typeReferenceDirectiveName, resolvedFile, false);
+                }
+                else {
+                    trace(host, Diagnostics.Type_reference_directive_0_was_not_resolved, typeReferenceDirectiveName);
+                }
+            }
+        }
+        else {
+            if (traceEnabled) {
+                trace(host, Diagnostics.Containing_file_is_not_specified_and_root_directory_cannot_be_determined_skipping_lookup_in_node_modules_folder);
+            }
+        }
+        return {
+            resolvedTypeReferenceDirective: resolvedFile
+                ? { primary: false, resolvedFileName: resolvedFile }
+                : undefined,
+            failedLookupLocations
+        };
+    }
+
+    /**
+      * Given a set of options, returns the set of type directive names
+      *   that should be included for this program automatically.
+      * This list could either come from the config file,
+      *   or from enumerating the types root + initial secondary types lookup location.
+      * More type directives might appear in the program later as a result of loading actual source files;
+      *   this list is only the set of defaults that are implicitly included.
+      */
+    export function getAutomaticTypeDirectiveNames(options: CompilerOptions, host: ModuleResolutionHost): string[] {
+        // Use explicit type list from tsconfig.json
+        if (options.types) {
+            return options.types;
+        }
+
+        // Walk the primary type lookup locations
+        const result: string[] = [];
+        if (host.directoryExists && host.getDirectories) {
+            const typeRoots = getEffectiveTypeRoots(options, host);
+            if (typeRoots) {
+                for (const root of typeRoots) {
+                    if (host.directoryExists(root)) {
+                        for (const typeDirectivePath of host.getDirectories(root)) {
+                            const normalized = normalizePath(typeDirectivePath);
+                            const packageJsonPath = pathToPackageJson(combinePaths(root, normalized));
+                            // tslint:disable-next-line:no-null-keyword
+                            const isNotNeededPackage = host.fileExists(packageJsonPath) && readJson(packageJsonPath, host).typings === null;
+                            if (!isNotNeededPackage) {
+                                // Return just the type directive names
+                                result.push(getBaseFileName(normalized));
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        return result;
+    }
+
+    export function resolveModuleName(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost): ResolvedModuleWithFailedLookupLocations {
+        const traceEnabled = isTraceEnabled(compilerOptions, host);
+        if (traceEnabled) {
+            trace(host, Diagnostics.Resolving_module_0_from_1, moduleName, containingFile);
+        }
+
+        let moduleResolution = compilerOptions.moduleResolution;
+        if (moduleResolution === undefined) {
+            moduleResolution = getEmitModuleKind(compilerOptions) === ModuleKind.CommonJS ? ModuleResolutionKind.NodeJs : ModuleResolutionKind.Classic;
+            if (traceEnabled) {
+                trace(host, Diagnostics.Module_resolution_kind_is_not_specified_using_0, ModuleResolutionKind[moduleResolution]);
+            }
+        }
+        else {
+            if (traceEnabled) {
+                trace(host, Diagnostics.Explicitly_specified_module_resolution_kind_Colon_0, ModuleResolutionKind[moduleResolution]);
+            }
+        }
+
+        let result: ResolvedModuleWithFailedLookupLocations;
+        switch (moduleResolution) {
+            case ModuleResolutionKind.NodeJs:
+                result = nodeModuleNameResolver(moduleName, containingFile, compilerOptions, host);
+                break;
+            case ModuleResolutionKind.Classic:
+                result = classicNameResolver(moduleName, containingFile, compilerOptions, host);
+                break;
+        }
+
+        if (traceEnabled) {
+            if (result.resolvedModule) {
+                trace(host, Diagnostics.Module_name_0_was_successfully_resolved_to_1, moduleName, result.resolvedModule.resolvedFileName);
+            }
+            else {
+                trace(host, Diagnostics.Module_name_0_was_not_resolved, moduleName);
+            }
+        }
+
+        return result;
+    }
+
+    /*
+     * Every module resolution kind can has its specific understanding how to load module from a specific path on disk
+     * I.e. for path '/a/b/c':
+     * - Node loader will first to try to check if '/a/b/c' points to a file with some supported extension and if this fails
+     * it will try to load module from directory: directory '/a/b/c' should exist and it should have either 'package.json' with
+     * 'typings' entry or file 'index' with some supported extension
+     * - Classic loader will only try to interpret '/a/b/c' as file.
+     */
+    type ResolutionKindSpecificLoader = (candidate: string, extensions: string[], failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState) => string;
+
+    /**
+     * Any module resolution kind can be augmented with optional settings: 'baseUrl', 'paths' and 'rootDirs' - they are used to
+     * mitigate differences between design time structure of the project and its runtime counterpart so the same import name
+     * can be resolved successfully by TypeScript compiler and runtime module loader.
+     * If these settings are set then loading procedure will try to use them to resolve module name and it can of failure it will
+     * fallback to standard resolution routine.
+     *
+     * - baseUrl - this setting controls how non-relative module names are resolved. If this setting is specified then non-relative
+     * names will be resolved relative to baseUrl: i.e. if baseUrl is '/a/b' then candidate location to resolve module name 'c/d' will
+     * be '/a/b/c/d'
+     * - paths - this setting can only be used when baseUrl is specified. allows to tune how non-relative module names
+     * will be resolved based on the content of the module name.
+     * Structure of 'paths' compiler options
+     * 'paths': {
+     *    pattern-1: [...substitutions],
+     *    pattern-2: [...substitutions],
+     *    ...
+     *    pattern-n: [...substitutions]
+     * }
+     * Pattern here is a string that can contain zero or one '*' character. During module resolution module name will be matched against
+     * all patterns in the list. Matching for patterns that don't contain '*' means that module name must be equal to pattern respecting the case.
+     * If pattern contains '*' then to match pattern "<prefix>*<suffix>" module name must start with the <prefix> and end with <suffix>.
+     * <MatchedStar> denotes part of the module name between <prefix> and <suffix>.
+     * If module name can be matches with multiple patterns then pattern with the longest prefix will be picked.
+     * After selecting pattern we'll use list of substitutions to get candidate locations of the module and the try to load module
+     * from the candidate location.
+     * Substitution is a string that can contain zero or one '*'. To get candidate location from substitution we'll pick every
+     * substitution in the list and replace '*' with <MatchedStar> string. If candidate location is not rooted it
+     * will be converted to absolute using baseUrl.
+     * For example:
+     * baseUrl: /a/b/c
+     * "paths": {
+     *     // match all module names
+     *     "*": [
+     *         "*",        // use matched name as is,
+     *                     // <matched name> will be looked as /a/b/c/<matched name>
+     *
+     *         "folder1/*" // substitution will convert matched name to 'folder1/<matched name>',
+     *                     // since it is not rooted then final candidate location will be /a/b/c/folder1/<matched name>
+     *     ],
+     *     // match module names that start with 'components/'
+     *     "components/*": [ "/root/components/*" ] // substitution will convert /components/folder1/<matched name> to '/root/components/folder1/<matched name>',
+     *                                              // it is rooted so it will be final candidate location
+     * }
+     *
+     * 'rootDirs' allows the project to be spreaded across multiple locations and resolve modules with relative names as if
+     * they were in the same location. For example lets say there are two files
+     * '/local/src/content/file1.ts'
+     * '/shared/components/contracts/src/content/protocols/file2.ts'
+     * After bundling content of '/shared/components/contracts/src' will be merged with '/local/src' so
+     * if file1 has the following import 'import {x} from "./protocols/file2"' it will be resolved successfully in runtime.
+     * 'rootDirs' provides the way to tell compiler that in order to get the whole project it should behave as if content of all
+     * root dirs were merged together.
+     * I.e. for the example above 'rootDirs' will have two entries: [ '/local/src', '/shared/components/contracts/src' ].
+     * Compiler will first convert './protocols/file2' into absolute path relative to the location of containing file:
+     * '/local/src/content/protocols/file2' and try to load it - failure.
+     * Then it will search 'rootDirs' looking for a longest matching prefix of this absolute path and if such prefix is found - absolute path will
+     * be converted to a path relative to found rootDir entry './content/protocols/file2' (*). As a last step compiler will check all remaining
+     * entries in 'rootDirs', use them to build absolute path out of (*) and try to resolve module from this location.
+     */
+    function tryLoadModuleUsingOptionalResolutionSettings(moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
+        failedLookupLocations: string[], supportedExtensions: string[], state: ModuleResolutionState): string {
+
+        if (moduleHasNonRelativeName(moduleName)) {
+            return tryLoadModuleUsingBaseUrl(moduleName, loader, failedLookupLocations, supportedExtensions, state);
+        }
+        else {
+            return tryLoadModuleUsingRootDirs(moduleName, containingDirectory, loader, failedLookupLocations, supportedExtensions, state);
+        }
+    }
+
+    function tryLoadModuleUsingRootDirs(moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
+        failedLookupLocations: string[], supportedExtensions: string[], state: ModuleResolutionState): string {
+
+        if (!state.compilerOptions.rootDirs) {
+            return undefined;
+        }
+
+        if (state.traceEnabled) {
+            trace(state.host, Diagnostics.rootDirs_option_is_set_using_it_to_resolve_relative_module_name_0, moduleName);
+        }
+
+        const candidate = normalizePath(combinePaths(containingDirectory, moduleName));
+
+        let matchedRootDir: string;
+        let matchedNormalizedPrefix: string;
+        for (const rootDir of state.compilerOptions.rootDirs) {
+            // rootDirs are expected to be absolute
+            // in case of tsconfig.json this will happen automatically - compiler will expand relative names
+            // using location of tsconfig.json as base location
+            let normalizedRoot = normalizePath(rootDir);
+            if (!endsWith(normalizedRoot, directorySeparator)) {
+                normalizedRoot += directorySeparator;
+            }
+            const isLongestMatchingPrefix =
+                startsWith(candidate, normalizedRoot) &&
+                (matchedNormalizedPrefix === undefined || matchedNormalizedPrefix.length < normalizedRoot.length);
+
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Checking_if_0_is_the_longest_matching_prefix_for_1_2, normalizedRoot, candidate, isLongestMatchingPrefix);
+            }
+
+            if (isLongestMatchingPrefix) {
+                matchedNormalizedPrefix = normalizedRoot;
+                matchedRootDir = rootDir;
+            }
+        }
+        if (matchedNormalizedPrefix) {
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Longest_matching_prefix_for_0_is_1, candidate, matchedNormalizedPrefix);
+            }
+            const suffix = candidate.substr(matchedNormalizedPrefix.length);
+
+            // first - try to load from a initial location
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Loading_0_from_the_root_dir_1_candidate_location_2, suffix, matchedNormalizedPrefix, candidate);
+            }
+            const resolvedFileName = loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(containingDirectory, state.host), state);
+            if (resolvedFileName) {
+                return resolvedFileName;
+            }
+
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Trying_other_entries_in_rootDirs);
+            }
+            // then try to resolve using remaining entries in rootDirs
+            for (const rootDir of state.compilerOptions.rootDirs) {
+                if (rootDir === matchedRootDir) {
+                    // skip the initially matched entry
+                    continue;
+                }
+                const candidate = combinePaths(normalizePath(rootDir), suffix);
+                if (state.traceEnabled) {
+                    trace(state.host, Diagnostics.Loading_0_from_the_root_dir_1_candidate_location_2, suffix, rootDir, candidate);
+                }
+                const baseDirectory = getDirectoryPath(candidate);
+                const resolvedFileName = loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(baseDirectory, state.host), state);
+                if (resolvedFileName) {
+                    return resolvedFileName;
+                }
+            }
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Module_resolution_using_rootDirs_has_failed);
+            }
+        }
+        return undefined;
+    }
+
+    function tryLoadModuleUsingBaseUrl(moduleName: string, loader: ResolutionKindSpecificLoader, failedLookupLocations: string[],
+        supportedExtensions: string[], state: ModuleResolutionState): string {
+
+        if (!state.compilerOptions.baseUrl) {
+            return undefined;
+        }
+        if (state.traceEnabled) {
+            trace(state.host, Diagnostics.baseUrl_option_is_set_to_0_using_this_value_to_resolve_non_relative_module_name_1, state.compilerOptions.baseUrl, moduleName);
+        }
+
+        // string is for exact match
+        let matchedPattern: Pattern | string | undefined = undefined;
+        if (state.compilerOptions.paths) {
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.paths_option_is_specified_looking_for_a_pattern_to_match_module_name_0, moduleName);
+            }
+            matchedPattern = matchPatternOrExact(getOwnKeys(state.compilerOptions.paths), moduleName);
+        }
+
+        if (matchedPattern) {
+            const matchedStar = typeof matchedPattern === "string" ? undefined : matchedText(matchedPattern, moduleName);
+            const matchedPatternText = typeof matchedPattern === "string" ? matchedPattern : patternText(matchedPattern);
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Module_name_0_matched_pattern_1, moduleName, matchedPatternText);
+            }
+            for (const subst of state.compilerOptions.paths[matchedPatternText]) {
+                const path = matchedStar ? subst.replace("*", matchedStar) : subst;
+                const candidate = normalizePath(combinePaths(state.compilerOptions.baseUrl, path));
+                if (state.traceEnabled) {
+                    trace(state.host, Diagnostics.Trying_substitution_0_candidate_module_location_Colon_1, subst, path);
+                }
+                const resolvedFileName = loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(getDirectoryPath(candidate), state.host), state);
+                if (resolvedFileName) {
+                    return resolvedFileName;
+                }
+            }
+            return undefined;
+        }
+        else {
+            const candidate = normalizePath(combinePaths(state.compilerOptions.baseUrl, moduleName));
+
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Resolving_module_name_0_relative_to_base_url_1_2, moduleName, state.compilerOptions.baseUrl, candidate);
+            }
+
+            return loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(getDirectoryPath(candidate), state.host), state);
+        }
+    }
+
+    export function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost): ResolvedModuleWithFailedLookupLocations {
+        const containingDirectory = getDirectoryPath(containingFile);
+        const supportedExtensions = getSupportedExtensions(compilerOptions);
+        const traceEnabled = isTraceEnabled(compilerOptions, host);
+
+        const failedLookupLocations: string[] = [];
+        const state = { compilerOptions, host, traceEnabled, skipTsx: false };
+        let resolvedFileName = tryLoadModuleUsingOptionalResolutionSettings(moduleName, containingDirectory, nodeLoadModuleByRelativeName,
+            failedLookupLocations, supportedExtensions, state);
+
+        let isExternalLibraryImport = false;
+        if (!resolvedFileName) {
+            if (moduleHasNonRelativeName(moduleName)) {
+                if (traceEnabled) {
+                    trace(host, Diagnostics.Loading_module_0_from_node_modules_folder, moduleName);
+                }
+                resolvedFileName = loadModuleFromNodeModules(moduleName, containingDirectory, failedLookupLocations, state, /*checkOneLevel*/ false);
+                isExternalLibraryImport = resolvedFileName !== undefined;
+            }
+            else {
+                const candidate = normalizePath(combinePaths(containingDirectory, moduleName));
+                resolvedFileName = nodeLoadModuleByRelativeName(candidate, supportedExtensions, failedLookupLocations, /*onlyRecordFailures*/ false, state);
+            }
+        }
+
+        if (resolvedFileName && host.realpath) {
+            const originalFileName = resolvedFileName;
+            resolvedFileName = normalizePath(host.realpath(resolvedFileName));
+            if (traceEnabled) {
+                trace(host, Diagnostics.Resolving_real_path_for_0_result_1, originalFileName, resolvedFileName);
+            }
+        }
+
+        return createResolvedModule(resolvedFileName, isExternalLibraryImport, failedLookupLocations);
+    }
+
+    function nodeLoadModuleByRelativeName(candidate: string, supportedExtensions: string[], failedLookupLocations: string[],
+        onlyRecordFailures: boolean, state: ModuleResolutionState): string {
+
+        if (state.traceEnabled) {
+            trace(state.host, Diagnostics.Loading_module_as_file_Slash_folder_candidate_module_location_0, candidate);
+        }
+
+        const resolvedFileName = !pathEndsWithDirectorySeparator(candidate) && loadModuleFromFile(candidate, supportedExtensions, failedLookupLocations, onlyRecordFailures, state);
+
+        return resolvedFileName || loadNodeModuleFromDirectory(supportedExtensions, candidate, failedLookupLocations, onlyRecordFailures, state);
+    }
+
+    /* @internal */
+    export function directoryProbablyExists(directoryName: string, host: { directoryExists?: (directoryName: string) => boolean }): boolean {
+        // if host does not support 'directoryExists' assume that directory will exist
+        return !host.directoryExists || host.directoryExists(directoryName);
+    }
+
+    /**
+     * @param {boolean} onlyRecordFailures - if true then function won't try to actually load files but instead record all attempts as failures. This flag is necessary
+     * in cases when we know upfront that all load attempts will fail (because containing folder does not exists) however we still need to record all failed lookup locations.
+     */
+    function loadModuleFromFile(candidate: string, extensions: string[], failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string | undefined {
+        // First, try adding an extension. An import of "foo" could be matched by a file "foo.ts", or "foo.js" by "foo.js.ts"
+        const resolvedByAddingExtension = tryAddingExtensions(candidate, extensions, failedLookupLocation, onlyRecordFailures, state);
+        if (resolvedByAddingExtension) {
+            return resolvedByAddingExtension;
+        }
+
+        // If that didn't work, try stripping a ".js" or ".jsx" extension and replacing it with a TypeScript one;
+        // e.g. "./foo.js" can be matched by "./foo.ts" or "./foo.d.ts"
+        if (hasJavaScriptFileExtension(candidate)) {
+            const extensionless = removeFileExtension(candidate);
+            if (state.traceEnabled) {
+                const extension = candidate.substring(extensionless.length);
+                trace(state.host, Diagnostics.File_name_0_has_a_1_extension_stripping_it, candidate, extension);
+            }
+            return tryAddingExtensions(extensionless, extensions, failedLookupLocation, onlyRecordFailures, state);
+        }
+    }
+
+    /** Try to return an existing file that adds one of the `extensions` to `candidate`. */
+    function tryAddingExtensions(candidate: string, extensions: string[], failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string | undefined {
+        if (!onlyRecordFailures) {
+            // check if containing folder exists - if it doesn't then just record failures for all supported extensions without disk probing
+            const directory = getDirectoryPath(candidate);
+            if (directory) {
+                onlyRecordFailures = !directoryProbablyExists(directory, state.host);
+            }
+        }
+        return forEach(extensions, ext =>
+            !(state.skipTsx && isJsxOrTsxExtension(ext)) && tryFile(candidate + ext, failedLookupLocation, onlyRecordFailures, state));
+    }
+
+    /** Return the file if it exists. */
+    function tryFile(fileName: string, failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string | undefined {
+        if (!onlyRecordFailures && state.host.fileExists(fileName)) {
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.File_0_exist_use_it_as_a_name_resolution_result, fileName);
+            }
+            return fileName;
+        }
+        else {
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.File_0_does_not_exist, fileName);
+            }
+            failedLookupLocation.push(fileName);
+            return undefined;
+        }
+    }
+
+    function loadNodeModuleFromDirectory(extensions: string[], candidate: string, failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string {
+        const packageJsonPath = pathToPackageJson(candidate);
+        const directoryExists = !onlyRecordFailures && directoryProbablyExists(candidate, state.host);
+        if (directoryExists && state.host.fileExists(packageJsonPath)) {
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.Found_package_json_at_0, packageJsonPath);
+            }
+            const typesFile = tryReadTypesSection(packageJsonPath, candidate, state);
+            if (typesFile) {
+                const onlyRecordFailures = !directoryProbablyExists(getDirectoryPath(typesFile), state.host);
+                // A package.json "typings" may specify an exact filename, or may choose to omit an extension.
+                const result = tryFile(typesFile, failedLookupLocation, onlyRecordFailures, state) ||
+                    tryAddingExtensions(typesFile, extensions, failedLookupLocation, onlyRecordFailures, state);
+                if (result) {
+                    return result;
+                }
+            }
+            else {
+                if (state.traceEnabled) {
+                    trace(state.host, Diagnostics.package_json_does_not_have_types_field);
+                }
+            }
+        }
+        else {
+            if (state.traceEnabled) {
+                trace(state.host, Diagnostics.File_0_does_not_exist, packageJsonPath);
+            }
+            // record package json as one of failed lookup locations - in the future if this file will appear it will invalidate resolution results
+            failedLookupLocation.push(packageJsonPath);
+        }
+
+        return loadModuleFromFile(combinePaths(candidate, "index"), extensions, failedLookupLocation, !directoryExists, state);
+    }
+
+    function pathToPackageJson(directory: string): string {
+        return combinePaths(directory, "package.json");
+    }
+
+    function loadModuleFromNodeModulesFolder(moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState): string {
+        const nodeModulesFolder = combinePaths(directory, "node_modules");
+        const nodeModulesFolderExists = directoryProbablyExists(nodeModulesFolder, state.host);
+        const candidate = normalizePath(combinePaths(nodeModulesFolder, moduleName));
+        const supportedExtensions = getSupportedExtensions(state.compilerOptions);
+
+        let result = loadModuleFromFile(candidate, supportedExtensions, failedLookupLocations, !nodeModulesFolderExists, state);
+        if (result) {
+            return result;
+        }
+        result = loadNodeModuleFromDirectory(supportedExtensions, candidate, failedLookupLocations, !nodeModulesFolderExists, state);
+        if (result) {
+            return result;
+        }
+    }
+
+    /* @internal */
+    export function loadModuleFromNodeModules(moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState, checkOneLevel: boolean): string {
+        directory = normalizeSlashes(directory);
+        while (true) {
+            const baseName = getBaseFileName(directory);
+            if (baseName !== "node_modules") {
+                // Try to load source from the package
+                const packageResult = loadModuleFromNodeModulesFolder(moduleName, directory, failedLookupLocations, state);
+                if (packageResult && hasTypeScriptFileExtension(packageResult)) {
+                    // Always prefer a TypeScript (.ts, .tsx, .d.ts) file shipped with the package
+                    return packageResult;
+                }
+                else {
+                    // Else prefer a types package over non-TypeScript results (e.g. JavaScript files)
+                    const typesResult = loadModuleFromNodeModulesFolder(combinePaths("@types", moduleName), directory, failedLookupLocations, state);
+                    if (typesResult || packageResult) {
+                        return typesResult || packageResult;
+                    }
+                }
+            }
+
+            const parentPath = getDirectoryPath(directory);
+            if (parentPath === directory || checkOneLevel) {
+                break;
+            }
+
+            directory = parentPath;
+        }
+        return undefined;
+    }
+
+    export function classicNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost): ResolvedModuleWithFailedLookupLocations {
+        const traceEnabled = isTraceEnabled(compilerOptions, host);
+        const state = { compilerOptions, host, traceEnabled, skipTsx: !compilerOptions.jsx };
+        const failedLookupLocations: string[] = [];
+        const supportedExtensions = getSupportedExtensions(compilerOptions);
+        let containingDirectory = getDirectoryPath(containingFile);
+
+        const resolvedFileName = tryLoadModuleUsingOptionalResolutionSettings(moduleName, containingDirectory, loadModuleFromFile, failedLookupLocations, supportedExtensions, state);
+        if (resolvedFileName) {
+            return createResolvedModule(resolvedFileName, /*isExternalLibraryImport*/false, failedLookupLocations);
+        }
+
+        let referencedSourceFile: string;
+        if (moduleHasNonRelativeName(moduleName)) {
+            while (true) {
+                const searchName = normalizePath(combinePaths(containingDirectory, moduleName));
+                referencedSourceFile = loadModuleFromFile(searchName, supportedExtensions, failedLookupLocations, /*onlyRecordFailures*/ false, state);
+                if (referencedSourceFile) {
+                    break;
+                }
+                const parentPath = getDirectoryPath(containingDirectory);
+                if (parentPath === containingDirectory) {
+                    break;
+                }
+                containingDirectory = parentPath;
+            }
+        }
+        else {
+            const candidate = normalizePath(combinePaths(containingDirectory, moduleName));
+            referencedSourceFile = loadModuleFromFile(candidate, supportedExtensions, failedLookupLocations, /*onlyRecordFailures*/ false, state);
+        }
+
+
+        return referencedSourceFile
+            ? { resolvedModule: { resolvedFileName: referencedSourceFile }, failedLookupLocations }
+            : { resolvedModule: undefined, failedLookupLocations };
+    }
+}

src/compiler/program.ts

@@ -4,15 +4,14 @@
 
 namespace ts {
     /** The version of the TypeScript compiler release */
+
     export const version = "2.1.0";
 
     const emptyArray: any[] = [];
 
-    const defaultTypeRoots = ["node_modules/@types"];
-
-    export function findConfigFile(searchPath: string, fileExists: (fileName: string) => boolean): string {
+    export function findConfigFile(searchPath: string, fileExists: (fileName: string) => boolean, configName = "tsconfig.json"): string {
         while (true) {
-            const fileName = combinePaths(searchPath, "tsconfig.json");
+            const fileName = combinePaths(searchPath, configName);
             if (fileExists(fileName)) {
                 return fileName;
             }
@@ -76,766 +75,6 @@ namespace ts {
         return getNormalizedPathFromPathComponents(commonPathComponents);
     }
 
-    function trace(host: ModuleResolutionHost, message: DiagnosticMessage, ...args: any[]): void;
-    function trace(host: ModuleResolutionHost, message: DiagnosticMessage): void {
-        host.trace(formatMessage.apply(undefined, arguments));
-    }
-
-    function isTraceEnabled(compilerOptions: CompilerOptions, host: ModuleResolutionHost): boolean {
-        return compilerOptions.traceResolution && host.trace !== undefined;
-    }
-
-    /* @internal */
-    export function hasZeroOrOneAsteriskCharacter(str: string): boolean {
-        let seenAsterisk = false;
-        for (let i = 0; i < str.length; i++) {
-            if (str.charCodeAt(i) === CharacterCodes.asterisk) {
-                if (!seenAsterisk) {
-                    seenAsterisk = true;
-                }
-                else {
-                    // have already seen asterisk
-                    return false;
-                }
-            }
-        }
-        return true;
-    }
-
-    function createResolvedModule(resolvedFileName: string, isExternalLibraryImport: boolean, failedLookupLocations: string[]): ResolvedModuleWithFailedLookupLocations {
-        return { resolvedModule: resolvedFileName ? { resolvedFileName, isExternalLibraryImport } : undefined, failedLookupLocations };
-    }
-
-    function moduleHasNonRelativeName(moduleName: string): boolean {
-        return !(isRootedDiskPath(moduleName) || isExternalModuleNameRelative(moduleName));
-    }
-
-    interface ModuleResolutionState {
-        host: ModuleResolutionHost;
-        compilerOptions: CompilerOptions;
-        traceEnabled: boolean;
-        // skip .tsx files if jsx is not enabled
-        skipTsx: boolean;
-    }
-
-    function tryReadTypesSection(packageJsonPath: string, baseDirectory: string, state: ModuleResolutionState): string {
-        const jsonContent = readJson(packageJsonPath, state.host);
-
-        function tryReadFromField(fieldName: string) {
-            if (hasProperty(jsonContent, fieldName)) {
-                const typesFile = (<any>jsonContent)[fieldName];
-                if (typeof typesFile === "string") {
-                    const typesFilePath = normalizePath(combinePaths(baseDirectory, typesFile));
-                    if (state.traceEnabled) {
-                        trace(state.host, Diagnostics.package_json_has_0_field_1_that_references_2, fieldName, typesFile, typesFilePath);
-                    }
-                    return typesFilePath;
-                }
-                else {
-                    if (state.traceEnabled) {
-                        trace(state.host, Diagnostics.Expected_type_of_0_field_in_package_json_to_be_string_got_1, fieldName, typeof typesFile);
-                    }
-                }
-            }
-        }
-
-        const typesFilePath = tryReadFromField("typings") || tryReadFromField("types");
-        if (typesFilePath) {
-            return typesFilePath;
-        }
-
-        // Use the main module for inferring types if no types package specified and the allowJs is set
-        if (state.compilerOptions.allowJs && jsonContent.main && typeof jsonContent.main === "string") {
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.No_types_specified_in_package_json_but_allowJs_is_set_so_returning_main_value_of_0, jsonContent.main);
-            }
-            const mainFilePath = normalizePath(combinePaths(baseDirectory, jsonContent.main));
-            return mainFilePath;
-        }
-        return undefined;
-    }
-
-    function readJson(path: string, host: ModuleResolutionHost): { typings?: string, types?: string, main?: string } {
-        try {
-            const jsonText = host.readFile(path);
-            return jsonText ? JSON.parse(jsonText) : {};
-        }
-        catch (e) {
-            // gracefully handle if readFile fails or returns not JSON
-            return {};
-        }
-    }
-
-    const typeReferenceExtensions = [".d.ts"];
-
-    function getEffectiveTypeRoots(options: CompilerOptions, host: ModuleResolutionHost) {
-        if (options.typeRoots) {
-            return options.typeRoots;
-        }
-
-        let currentDirectory: string;
-        if (options.configFilePath) {
-            currentDirectory = getDirectoryPath(options.configFilePath);
-        }
-        else if (host.getCurrentDirectory) {
-            currentDirectory = host.getCurrentDirectory();
-        }
-
-        if (!currentDirectory) {
-            return undefined;
-        }
-        return map(defaultTypeRoots, d => combinePaths(currentDirectory, d));
-    }
-
-    /**
-     * @param {string | undefined} containingFile - file that contains type reference directive, can be undefined if containing file is unknown.
-     * This is possible in case if resolution is performed for directives specified via 'types' parameter. In this case initial path for secondary lookups
-     * is assumed to be the same as root directory of the project.
-     */
-    export function resolveTypeReferenceDirective(typeReferenceDirectiveName: string, containingFile: string, options: CompilerOptions, host: ModuleResolutionHost): ResolvedTypeReferenceDirectiveWithFailedLookupLocations {
-        const traceEnabled = isTraceEnabled(options, host);
-        const moduleResolutionState: ModuleResolutionState = {
-            compilerOptions: options,
-            host: host,
-            skipTsx: true,
-            traceEnabled
-        };
-
-        const typeRoots = getEffectiveTypeRoots(options, host);
-        if (traceEnabled) {
-            if (containingFile === undefined) {
-                if (typeRoots === undefined) {
-                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_not_set_root_directory_not_set, typeReferenceDirectiveName);
-                }
-                else {
-                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_not_set_root_directory_1, typeReferenceDirectiveName, typeRoots);
-                }
-            }
-            else {
-                if (typeRoots === undefined) {
-                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_1_root_directory_not_set, typeReferenceDirectiveName, containingFile);
-                }
-                else {
-                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_1_root_directory_2, typeReferenceDirectiveName, containingFile, typeRoots);
-                }
-            }
-        }
-
-        const failedLookupLocations: string[] = [];
-
-        // Check primary library paths
-        if (typeRoots && typeRoots.length) {
-            if (traceEnabled) {
-                trace(host, Diagnostics.Resolving_with_primary_search_path_0, typeRoots.join(", "));
-            }
-            const primarySearchPaths = typeRoots;
-            for (const typeRoot of primarySearchPaths) {
-                const candidate = combinePaths(typeRoot, typeReferenceDirectiveName);
-                const candidateDirectory = getDirectoryPath(candidate);
-                const resolvedFile = loadNodeModuleFromDirectory(typeReferenceExtensions, candidate, failedLookupLocations,
-                    !directoryProbablyExists(candidateDirectory, host), moduleResolutionState);
-
-                if (resolvedFile) {
-                    if (traceEnabled) {
-                        trace(host, Diagnostics.Type_reference_directive_0_was_successfully_resolved_to_1_primary_Colon_2, typeReferenceDirectiveName, resolvedFile, true);
-                    }
-                    return {
-                        resolvedTypeReferenceDirective: { primary: true, resolvedFileName: resolvedFile },
-                        failedLookupLocations
-                    };
-                }
-            }
-        }
-        else {
-            if (traceEnabled) {
-                trace(host, Diagnostics.Root_directory_cannot_be_determined_skipping_primary_search_paths);
-            }
-        }
-
-        let resolvedFile: string;
-        let initialLocationForSecondaryLookup: string;
-        if (containingFile) {
-            initialLocationForSecondaryLookup = getDirectoryPath(containingFile);
-        }
-
-        if (initialLocationForSecondaryLookup !== undefined) {
-            // check secondary locations
-            if (traceEnabled) {
-                trace(host, Diagnostics.Looking_up_in_node_modules_folder_initial_location_0, initialLocationForSecondaryLookup);
-            }
-            resolvedFile = loadModuleFromNodeModules(typeReferenceDirectiveName, initialLocationForSecondaryLookup, failedLookupLocations, moduleResolutionState);
-            if (traceEnabled) {
-                if (resolvedFile) {
-                    trace(host, Diagnostics.Type_reference_directive_0_was_successfully_resolved_to_1_primary_Colon_2, typeReferenceDirectiveName, resolvedFile, false);
-                }
-                else {
-                    trace(host, Diagnostics.Type_reference_directive_0_was_not_resolved, typeReferenceDirectiveName);
-                }
-            }
-        }
-        else {
-            if (traceEnabled) {
-                trace(host, Diagnostics.Containing_file_is_not_specified_and_root_directory_cannot_be_determined_skipping_lookup_in_node_modules_folder);
-            }
-        }
-        return {
-            resolvedTypeReferenceDirective: resolvedFile
-                ? { primary: false, resolvedFileName: resolvedFile }
-                : undefined,
-            failedLookupLocations
-        };
-    }
-
-    export function resolveModuleName(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost): ResolvedModuleWithFailedLookupLocations {
-        const traceEnabled = isTraceEnabled(compilerOptions, host);
-        if (traceEnabled) {
-            trace(host, Diagnostics.Resolving_module_0_from_1, moduleName, containingFile);
-        }
-
-        let moduleResolution = compilerOptions.moduleResolution;
-        if (moduleResolution === undefined) {
-            moduleResolution = getEmitModuleKind(compilerOptions) === ModuleKind.CommonJS ? ModuleResolutionKind.NodeJs : ModuleResolutionKind.Classic;
-            if (traceEnabled) {
-                trace(host, Diagnostics.Module_resolution_kind_is_not_specified_using_0, ModuleResolutionKind[moduleResolution]);
-            }
-        }
-        else {
-            if (traceEnabled) {
-                trace(host, Diagnostics.Explicitly_specified_module_resolution_kind_Colon_0, ModuleResolutionKind[moduleResolution]);
-            }
-        }
-
-        let result: ResolvedModuleWithFailedLookupLocations;
-        switch (moduleResolution) {
-            case ModuleResolutionKind.NodeJs:
-                result = nodeModuleNameResolver(moduleName, containingFile, compilerOptions, host);
-                break;
-            case ModuleResolutionKind.Classic:
-                result = classicNameResolver(moduleName, containingFile, compilerOptions, host);
-                break;
-        }
-
-        if (traceEnabled) {
-            if (result.resolvedModule) {
-                trace(host, Diagnostics.Module_name_0_was_successfully_resolved_to_1, moduleName, result.resolvedModule.resolvedFileName);
-            }
-            else {
-                trace(host, Diagnostics.Module_name_0_was_not_resolved, moduleName);
-            }
-        }
-
-        return result;
-    }
-
-    /*
-     * Every module resolution kind can has its specific understanding how to load module from a specific path on disk
-     * I.e. for path '/a/b/c':
-     * - Node loader will first to try to check if '/a/b/c' points to a file with some supported extension and if this fails
-     * it will try to load module from directory: directory '/a/b/c' should exist and it should have either 'package.json' with
-     * 'typings' entry or file 'index' with some supported extension
-     * - Classic loader will only try to interpret '/a/b/c' as file.
-     */
-    type ResolutionKindSpecificLoader = (candidate: string, extensions: string[], failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState) => string;
-
-    /**
-     * Any module resolution kind can be augmented with optional settings: 'baseUrl', 'paths' and 'rootDirs' - they are used to
-     * mitigate differences between design time structure of the project and its runtime counterpart so the same import name
-     * can be resolved successfully by TypeScript compiler and runtime module loader.
-     * If these settings are set then loading procedure will try to use them to resolve module name and it can of failure it will
-     * fallback to standard resolution routine.
-     *
-     * - baseUrl - this setting controls how non-relative module names are resolved. If this setting is specified then non-relative
-     * names will be resolved relative to baseUrl: i.e. if baseUrl is '/a/b' then candidate location to resolve module name 'c/d' will
-     * be '/a/b/c/d'
-     * - paths - this setting can only be used when baseUrl is specified. allows to tune how non-relative module names
-     * will be resolved based on the content of the module name.
-     * Structure of 'paths' compiler options
-     * 'paths': {
-     *    pattern-1: [...substitutions],
-     *    pattern-2: [...substitutions],
-     *    ...
-     *    pattern-n: [...substitutions]
-     * }
-     * Pattern here is a string that can contain zero or one '*' character. During module resolution module name will be matched against
-     * all patterns in the list. Matching for patterns that don't contain '*' means that module name must be equal to pattern respecting the case.
-     * If pattern contains '*' then to match pattern "<prefix>*<suffix>" module name must start with the <prefix> and end with <suffix>.
-     * <MatchedStar> denotes part of the module name between <prefix> and <suffix>.
-     * If module name can be matches with multiple patterns then pattern with the longest prefix will be picked.
-     * After selecting pattern we'll use list of substitutions to get candidate locations of the module and the try to load module
-     * from the candidate location.
-     * Substitution is a string that can contain zero or one '*'. To get candidate location from substitution we'll pick every
-     * substitution in the list and replace '*' with <MatchedStar> string. If candidate location is not rooted it
-     * will be converted to absolute using baseUrl.
-     * For example:
-     * baseUrl: /a/b/c
-     * "paths": {
-     *     // match all module names
-     *     "*": [
-     *         "*",        // use matched name as is,
-     *                     // <matched name> will be looked as /a/b/c/<matched name>
-     *
-     *         "folder1/*" // substitution will convert matched name to 'folder1/<matched name>',
-     *                     // since it is not rooted then final candidate location will be /a/b/c/folder1/<matched name>
-     *     ],
-     *     // match module names that start with 'components/'
-     *     "components/*": [ "/root/components/*" ] // substitution will convert /components/folder1/<matched name> to '/root/components/folder1/<matched name>',
-     *                                              // it is rooted so it will be final candidate location
-     * }
-     *
-     * 'rootDirs' allows the project to be spreaded across multiple locations and resolve modules with relative names as if
-     * they were in the same location. For example lets say there are two files
-     * '/local/src/content/file1.ts'
-     * '/shared/components/contracts/src/content/protocols/file2.ts'
-     * After bundling content of '/shared/components/contracts/src' will be merged with '/local/src' so
-     * if file1 has the following import 'import {x} from "./protocols/file2"' it will be resolved successfully in runtime.
-     * 'rootDirs' provides the way to tell compiler that in order to get the whole project it should behave as if content of all
-     * root dirs were merged together.
-     * I.e. for the example above 'rootDirs' will have two entries: [ '/local/src', '/shared/components/contracts/src' ].
-     * Compiler will first convert './protocols/file2' into absolute path relative to the location of containing file:
-     * '/local/src/content/protocols/file2' and try to load it - failure.
-     * Then it will search 'rootDirs' looking for a longest matching prefix of this absolute path and if such prefix is found - absolute path will
-     * be converted to a path relative to found rootDir entry './content/protocols/file2' (*). As a last step compiler will check all remaining
-     * entries in 'rootDirs', use them to build absolute path out of (*) and try to resolve module from this location.
-     */
-    function tryLoadModuleUsingOptionalResolutionSettings(moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
-        failedLookupLocations: string[], supportedExtensions: string[], state: ModuleResolutionState): string {
-
-        if (moduleHasNonRelativeName(moduleName)) {
-            return tryLoadModuleUsingBaseUrl(moduleName, loader, failedLookupLocations, supportedExtensions, state);
-        }
-        else {
-            return tryLoadModuleUsingRootDirs(moduleName, containingDirectory, loader, failedLookupLocations, supportedExtensions, state);
-        }
-    }
-
-    function tryLoadModuleUsingRootDirs(moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
-        failedLookupLocations: string[], supportedExtensions: string[], state: ModuleResolutionState): string {
-
-        if (!state.compilerOptions.rootDirs) {
-            return undefined;
-        }
-
-        if (state.traceEnabled) {
-            trace(state.host, Diagnostics.rootDirs_option_is_set_using_it_to_resolve_relative_module_name_0, moduleName);
-        }
-
-        const candidate = normalizePath(combinePaths(containingDirectory, moduleName));
-
-        let matchedRootDir: string;
-        let matchedNormalizedPrefix: string;
-        for (const rootDir of state.compilerOptions.rootDirs) {
-            // rootDirs are expected to be absolute
-            // in case of tsconfig.json this will happen automatically - compiler will expand relative names
-            // using location of tsconfig.json as base location
-            let normalizedRoot = normalizePath(rootDir);
-            if (!endsWith(normalizedRoot, directorySeparator)) {
-                normalizedRoot += directorySeparator;
-            }
-            const isLongestMatchingPrefix =
-                startsWith(candidate, normalizedRoot) &&
-                (matchedNormalizedPrefix === undefined || matchedNormalizedPrefix.length < normalizedRoot.length);
-
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Checking_if_0_is_the_longest_matching_prefix_for_1_2, normalizedRoot, candidate, isLongestMatchingPrefix);
-            }
-
-            if (isLongestMatchingPrefix) {
-                matchedNormalizedPrefix = normalizedRoot;
-                matchedRootDir = rootDir;
-            }
-        }
-        if (matchedNormalizedPrefix) {
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Longest_matching_prefix_for_0_is_1, candidate, matchedNormalizedPrefix);
-            }
-            const suffix = candidate.substr(matchedNormalizedPrefix.length);
-
-            // first - try to load from a initial location
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Loading_0_from_the_root_dir_1_candidate_location_2, suffix, matchedNormalizedPrefix, candidate);
-            }
-            const resolvedFileName = loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(containingDirectory, state.host), state);
-            if (resolvedFileName) {
-                return resolvedFileName;
-            }
-
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Trying_other_entries_in_rootDirs);
-            }
-            // then try to resolve using remaining entries in rootDirs
-            for (const rootDir of state.compilerOptions.rootDirs) {
-                if (rootDir === matchedRootDir) {
-                    // skip the initially matched entry
-                    continue;
-                }
-                const candidate = combinePaths(normalizePath(rootDir), suffix);
-                if (state.traceEnabled) {
-                    trace(state.host, Diagnostics.Loading_0_from_the_root_dir_1_candidate_location_2, suffix, rootDir, candidate);
-                }
-                const baseDirectory = getDirectoryPath(candidate);
-                const resolvedFileName = loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(baseDirectory, state.host), state);
-                if (resolvedFileName) {
-                    return resolvedFileName;
-                }
-            }
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Module_resolution_using_rootDirs_has_failed);
-            }
-        }
-        return undefined;
-    }
-
-    function tryLoadModuleUsingBaseUrl(moduleName: string, loader: ResolutionKindSpecificLoader, failedLookupLocations: string[],
-        supportedExtensions: string[], state: ModuleResolutionState): string {
-
-        if (!state.compilerOptions.baseUrl) {
-            return undefined;
-        }
-        if (state.traceEnabled) {
-            trace(state.host, Diagnostics.baseUrl_option_is_set_to_0_using_this_value_to_resolve_non_relative_module_name_1, state.compilerOptions.baseUrl, moduleName);
-        }
-
-        // string is for exact match
-        let matchedPattern: Pattern | string | undefined = undefined;
-        if (state.compilerOptions.paths) {
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.paths_option_is_specified_looking_for_a_pattern_to_match_module_name_0, moduleName);
-            }
-            matchedPattern = matchPatternOrExact(getOwnKeys(state.compilerOptions.paths), moduleName);
-        }
-
-        if (matchedPattern) {
-            const matchedStar = typeof matchedPattern === "string" ? undefined : matchedText(matchedPattern, moduleName);
-            const matchedPatternText = typeof matchedPattern === "string" ? matchedPattern : patternText(matchedPattern);
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Module_name_0_matched_pattern_1, moduleName, matchedPatternText);
-            }
-            for (const subst of state.compilerOptions.paths[matchedPatternText]) {
-                const path = matchedStar ? subst.replace("*", matchedStar) : subst;
-                const candidate = normalizePath(combinePaths(state.compilerOptions.baseUrl, path));
-                if (state.traceEnabled) {
-                    trace(state.host, Diagnostics.Trying_substitution_0_candidate_module_location_Colon_1, subst, path);
-                }
-                const resolvedFileName = loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(getDirectoryPath(candidate), state.host), state);
-                if (resolvedFileName) {
-                    return resolvedFileName;
-                }
-            }
-            return undefined;
-        }
-        else {
-            const candidate = normalizePath(combinePaths(state.compilerOptions.baseUrl, moduleName));
-
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Resolving_module_name_0_relative_to_base_url_1_2, moduleName, state.compilerOptions.baseUrl, candidate);
-            }
-
-            return loader(candidate, supportedExtensions, failedLookupLocations, !directoryProbablyExists(getDirectoryPath(candidate), state.host), state);
-        }
-    }
-
-    /**
-     * patternStrings contains both pattern strings (containing "*") and regular strings.
-     * Return an exact match if possible, or a pattern match, or undefined.
-     * (These are verified by verifyCompilerOptions to have 0 or 1 "*" characters.)
-     */
-    function matchPatternOrExact(patternStrings: string[], candidate: string): string | Pattern | undefined {
-        const patterns: Pattern[] = [];
-        for (const patternString of patternStrings) {
-            const pattern = tryParsePattern(patternString);
-            if (pattern) {
-                patterns.push(pattern);
-            }
-            else if (patternString === candidate) {
-                // pattern was matched as is - no need to search further
-                return patternString;
-            }
-        }
-
-        return findBestPatternMatch(patterns, _ => _, candidate);
-    }
-
-    function patternText({prefix, suffix}: Pattern): string {
-        return `${prefix}*${suffix}`;
-    }
-
-    /**
-     * Given that candidate matches pattern, returns the text matching the '*'.
-     * E.g.: matchedText(tryParsePattern("foo*baz"), "foobarbaz") === "bar"
-     */
-    function matchedText(pattern: Pattern, candidate: string): string {
-        Debug.assert(isPatternMatch(pattern, candidate));
-        return candidate.substr(pattern.prefix.length, candidate.length - pattern.suffix.length);
-    }
-
-    /** Return the object corresponding to the best pattern to match `candidate`. */
-    /* @internal */
-    export function findBestPatternMatch<T>(values: T[], getPattern: (value: T) => Pattern, candidate: string): T | undefined {
-        let matchedValue: T | undefined = undefined;
-        // use length of prefix as betterness criteria
-        let longestMatchPrefixLength = -1;
-
-        for (const v of values) {
-            const pattern = getPattern(v);
-            if (isPatternMatch(pattern, candidate) && pattern.prefix.length > longestMatchPrefixLength) {
-                longestMatchPrefixLength = pattern.prefix.length;
-                matchedValue = v;
-            }
-        }
-
-        return matchedValue;
-    }
-
-    function isPatternMatch({prefix, suffix}: Pattern, candidate: string) {
-        return candidate.length >= prefix.length + suffix.length &&
-               startsWith(candidate, prefix) &&
-               endsWith(candidate, suffix);
-    }
-
-    /* @internal */
-    export function tryParsePattern(pattern: string): Pattern | undefined {
-        // This should be verified outside of here and a proper error thrown.
-        Debug.assert(hasZeroOrOneAsteriskCharacter(pattern));
-        const indexOfStar = pattern.indexOf("*");
-        return indexOfStar === -1 ? undefined : {
-            prefix: pattern.substr(0, indexOfStar),
-            suffix: pattern.substr(indexOfStar + 1)
-        };
-    }
-
-    export function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost): ResolvedModuleWithFailedLookupLocations {
-        const containingDirectory = getDirectoryPath(containingFile);
-        const supportedExtensions = getSupportedExtensions(compilerOptions);
-        const traceEnabled = isTraceEnabled(compilerOptions, host);
-
-        const failedLookupLocations: string[] = [];
-        const state = { compilerOptions, host, traceEnabled, skipTsx: false };
-        let resolvedFileName = tryLoadModuleUsingOptionalResolutionSettings(moduleName, containingDirectory, nodeLoadModuleByRelativeName,
-            failedLookupLocations, supportedExtensions, state);
-
-        let isExternalLibraryImport = false;
-        if (!resolvedFileName) {
-            if (moduleHasNonRelativeName(moduleName)) {
-                if (traceEnabled) {
-                    trace(host, Diagnostics.Loading_module_0_from_node_modules_folder, moduleName);
-                }
-                resolvedFileName = loadModuleFromNodeModules(moduleName, containingDirectory, failedLookupLocations, state);
-                isExternalLibraryImport = resolvedFileName !== undefined;
-            }
-            else {
-                const candidate = normalizePath(combinePaths(containingDirectory, moduleName));
-                resolvedFileName = nodeLoadModuleByRelativeName(candidate, supportedExtensions, failedLookupLocations, /*onlyRecordFailures*/ false, state);
-            }
-        }
-
-        if (resolvedFileName && host.realpath) {
-            const originalFileName = resolvedFileName;
-            resolvedFileName = normalizePath(host.realpath(resolvedFileName));
-            if (traceEnabled) {
-                trace(host, Diagnostics.Resolving_real_path_for_0_result_1, originalFileName, resolvedFileName);
-            }
-        }
-
-        return createResolvedModule(resolvedFileName, isExternalLibraryImport, failedLookupLocations);
-    }
-
-    function nodeLoadModuleByRelativeName(candidate: string, supportedExtensions: string[], failedLookupLocations: string[],
-        onlyRecordFailures: boolean, state: ModuleResolutionState): string {
-
-        if (state.traceEnabled) {
-            trace(state.host, Diagnostics.Loading_module_as_file_Slash_folder_candidate_module_location_0, candidate);
-        }
-
-        const resolvedFileName = loadModuleFromFile(candidate, supportedExtensions, failedLookupLocations, onlyRecordFailures, state);
-
-        return resolvedFileName || loadNodeModuleFromDirectory(supportedExtensions, candidate, failedLookupLocations, onlyRecordFailures, state);
-    }
-
-    /* @internal */
-    export function directoryProbablyExists(directoryName: string, host: { directoryExists?: (directoryName: string) => boolean }): boolean {
-        // if host does not support 'directoryExists' assume that directory will exist
-        return !host.directoryExists || host.directoryExists(directoryName);
-    }
-
-    /**
-     * @param {boolean} onlyRecordFailures - if true then function won't try to actually load files but instead record all attempts as failures. This flag is necessary
-     * in cases when we know upfront that all load attempts will fail (because containing folder does not exists) however we still need to record all failed lookup locations.
-     */
-    function loadModuleFromFile(candidate: string, extensions: string[], failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string {
-        // First try to keep/add an extension: importing "./foo.ts" can be matched by a file "./foo.ts", and "./foo" by "./foo.d.ts"
-        const resolvedByAddingOrKeepingExtension = loadModuleFromFileWorker(candidate, extensions, failedLookupLocation, onlyRecordFailures, state);
-        if (resolvedByAddingOrKeepingExtension) {
-            return resolvedByAddingOrKeepingExtension;
-        }
-        // Then try stripping a ".js" or ".jsx" extension and replacing it with a TypeScript one, e.g. "./foo.js" can be matched by "./foo.ts" or "./foo.d.ts"
-        if (hasJavaScriptFileExtension(candidate)) {
-            const extensionless = removeFileExtension(candidate);
-            if (state.traceEnabled) {
-                const extension = candidate.substring(extensionless.length);
-                trace(state.host, Diagnostics.File_name_0_has_a_1_extension_stripping_it, candidate, extension);
-            }
-            return loadModuleFromFileWorker(extensionless, extensions, failedLookupLocation, onlyRecordFailures, state);
-        }
-    }
-
-    function loadModuleFromFileWorker(candidate: string, extensions: string[], failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string {
-        if (!onlyRecordFailures) {
-            // check if containing folder exists - if it doesn't then just record failures for all supported extensions without disk probing
-            const directory = getDirectoryPath(candidate);
-            if (directory) {
-                onlyRecordFailures = !directoryProbablyExists(directory, state.host);
-            }
-        }
-        return forEach(extensions, tryLoad);
-
-        function tryLoad(ext: string): string {
-            if (state.skipTsx && isJsxOrTsxExtension(ext)) {
-                return undefined;
-            }
-            const fileName = fileExtensionIs(candidate, ext) ? candidate : candidate + ext;
-            if (!onlyRecordFailures && state.host.fileExists(fileName)) {
-                if (state.traceEnabled) {
-                    trace(state.host, Diagnostics.File_0_exist_use_it_as_a_name_resolution_result, fileName);
-                }
-                return fileName;
-            }
-            else {
-                if (state.traceEnabled) {
-                    trace(state.host, Diagnostics.File_0_does_not_exist, fileName);
-                }
-                failedLookupLocation.push(fileName);
-                return undefined;
-            }
-        }
-    }
-
-    function loadNodeModuleFromDirectory(extensions: string[], candidate: string, failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string {
-        const packageJsonPath = pathToPackageJson(candidate);
-        const directoryExists = !onlyRecordFailures && directoryProbablyExists(candidate, state.host);
-        if (directoryExists && state.host.fileExists(packageJsonPath)) {
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Found_package_json_at_0, packageJsonPath);
-            }
-            const typesFile = tryReadTypesSection(packageJsonPath, candidate, state);
-            if (typesFile) {
-                const result = loadModuleFromFile(typesFile, extensions, failedLookupLocation, !directoryProbablyExists(getDirectoryPath(typesFile), state.host), state);
-                if (result) {
-                    return result;
-                }
-            }
-            else {
-                if (state.traceEnabled) {
-                    trace(state.host, Diagnostics.package_json_does_not_have_types_field);
-                }
-            }
-        }
-        else {
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.File_0_does_not_exist, packageJsonPath);
-            }
-            // record package json as one of failed lookup locations - in the future if this file will appear it will invalidate resolution results
-            failedLookupLocation.push(packageJsonPath);
-        }
-
-        return loadModuleFromFile(combinePaths(candidate, "index"), extensions, failedLookupLocation, !directoryExists, state);
-    }
-
-    function pathToPackageJson(directory: string): string {
-        return combinePaths(directory, "package.json");
-    }
-
-    function loadModuleFromNodeModulesFolder(moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState): string {
-        const nodeModulesFolder = combinePaths(directory, "node_modules");
-        const nodeModulesFolderExists = directoryProbablyExists(nodeModulesFolder, state.host);
-        const candidate = normalizePath(combinePaths(nodeModulesFolder, moduleName));
-        const supportedExtensions = getSupportedExtensions(state.compilerOptions);
-
-        let result = loadModuleFromFile(candidate, supportedExtensions, failedLookupLocations, !nodeModulesFolderExists, state);
-        if (result) {
-            return result;
-        }
-        result = loadNodeModuleFromDirectory(supportedExtensions, candidate, failedLookupLocations, !nodeModulesFolderExists, state);
-        if (result) {
-            return result;
-        }
-    }
-
-    function loadModuleFromNodeModules(moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState): string {
-        directory = normalizeSlashes(directory);
-        while (true) {
-            const baseName = getBaseFileName(directory);
-            if (baseName !== "node_modules") {
-                // Try to load source from the package
-                const packageResult = loadModuleFromNodeModulesFolder(moduleName, directory, failedLookupLocations, state);
-                if (packageResult && hasTypeScriptFileExtension(packageResult)) {
-                    // Always prefer a TypeScript (.ts, .tsx, .d.ts) file shipped with the package
-                    return packageResult;
-                }
-                else {
-                    // Else prefer a types package over non-TypeScript results (e.g. JavaScript files)
-                    const typesResult = loadModuleFromNodeModulesFolder(combinePaths("@types", moduleName), directory, failedLookupLocations, state);
-                    if (typesResult || packageResult) {
-                        return typesResult || packageResult;
-                    }
-                }
-            }
-
-            const parentPath = getDirectoryPath(directory);
-            if (parentPath === directory) {
-                break;
-            }
-
-            directory = parentPath;
-        }
-        return undefined;
-    }
-
-    export function classicNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost): ResolvedModuleWithFailedLookupLocations {
-        const traceEnabled = isTraceEnabled(compilerOptions, host);
-        const state = { compilerOptions, host, traceEnabled, skipTsx: !compilerOptions.jsx };
-        const failedLookupLocations: string[] = [];
-        const supportedExtensions = getSupportedExtensions(compilerOptions);
-        let containingDirectory = getDirectoryPath(containingFile);
-
-        const resolvedFileName = tryLoadModuleUsingOptionalResolutionSettings(moduleName, containingDirectory, loadModuleFromFile, failedLookupLocations, supportedExtensions, state);
-        if (resolvedFileName) {
-            return createResolvedModule(resolvedFileName, /*isExternalLibraryImport*/false, failedLookupLocations);
-        }
-
-        let referencedSourceFile: string;
-        if (moduleHasNonRelativeName(moduleName)) {
-            while (true) {
-                const searchName = normalizePath(combinePaths(containingDirectory, moduleName));
-                referencedSourceFile = loadModuleFromFile(searchName, supportedExtensions, failedLookupLocations, /*onlyRecordFailures*/ false, state);
-                if (referencedSourceFile) {
-                    break;
-                }
-                const parentPath = getDirectoryPath(containingDirectory);
-                if (parentPath === containingDirectory) {
-                    break;
-                }
-                containingDirectory = parentPath;
-            }
-        }
-        else {
-            const candidate = normalizePath(combinePaths(containingDirectory, moduleName));
-            referencedSourceFile = loadModuleFromFile(candidate, supportedExtensions, failedLookupLocations, /*onlyRecordFailures*/ false, state);
-        }
-
-
-        return referencedSourceFile
-            ? { resolvedModule: { resolvedFileName: referencedSourceFile }, failedLookupLocations }
-            : { resolvedModule: undefined, failedLookupLocations };
-    }
-
-    /* @internal */
-    export const defaultInitCompilerOptions: CompilerOptions = {
-        module: ModuleKind.CommonJS,
-        target: ScriptTarget.ES5,
-        noImplicitAny: false,
-        sourceMap: false,
-    };
-
     interface OutputFingerprint {
         hash: string;
         byteOrderMark: boolean;
@@ -967,6 +206,7 @@ namespace ts {
             readFile: fileName => sys.readFile(fileName),
             trace: (s: string) => sys.write(s + newLine),
             directoryExists: directoryName => sys.directoryExists(directoryName),
+            getEnvironmentVariable: name => getEnvironmentVariable(name, /*host*/ undefined),
             getDirectories: (path: string) => sys.getDirectories(path),
             realpath
         };
@@ -1049,44 +289,6 @@ namespace ts {
         return resolutions;
     }
 
-    /**
-      * Given a set of options, returns the set of type directive names
-      *   that should be included for this program automatically.
-      * This list could either come from the config file,
-      *   or from enumerating the types root + initial secondary types lookup location.
-      * More type directives might appear in the program later as a result of loading actual source files;
-      *   this list is only the set of defaults that are implicitly included.
-      */
-    export function getAutomaticTypeDirectiveNames(options: CompilerOptions, host: ModuleResolutionHost): string[] {
-        // Use explicit type list from tsconfig.json
-        if (options.types) {
-            return options.types;
-        }
-
-        // Walk the primary type lookup locations
-        const result: string[] = [];
-        if (host.directoryExists && host.getDirectories) {
-            const typeRoots = getEffectiveTypeRoots(options, host);
-            if (typeRoots) {
-                for (const root of typeRoots) {
-                    if (host.directoryExists(root)) {
-                        for (const typeDirectivePath of host.getDirectories(root)) {
-                            const normalized = normalizePath(typeDirectivePath);
-                            const packageJsonPath = pathToPackageJson(combinePaths(root, normalized));
-                            // tslint:disable-next-line:no-null-keyword
-                            const isNotNeededPackage = host.fileExists(packageJsonPath) && readJson(packageJsonPath, host).typings === null;
-                            if (!isNotNeededPackage) {
-                                // Return just the type directive names
-                                result.push(getBaseFileName(normalized));
-                            }
-                        }
-                    }
-                }
-            }
-        }
-        return result;
-    }
-
     export function createProgram(rootNames: string[], options: CompilerOptions, host?: CompilerHost, oldProgram?: Program): Program {
         let program: Program;
         let files: SourceFile[] = [];
@@ -1105,7 +307,7 @@ namespace ts {
         // - This calls resolveModuleNames, and then calls findSourceFile for each resolved module.
         // As all these operations happen - and are nested - within the createProgram call, they close over the below variables.
         // The current resolution depth is tracked by incrementing/decrementing as the depth first search progresses.
-        const maxNodeModulesJsDepth = typeof options.maxNodeModuleJsDepth === "number" ? options.maxNodeModuleJsDepth : 2;
+        const maxNodeModulesJsDepth = typeof options.maxNodeModuleJsDepth === "number" ? options.maxNodeModuleJsDepth : 0;
         let currentNodeModulesDepth = 0;
 
         // If a module has some of its imports skipped due to being at the depth limit under node_modules, then track
@@ -1209,7 +411,8 @@ namespace ts {
             getSymbolCount: () => getDiagnosticsProducingTypeChecker().getSymbolCount(),
             getTypeCount: () => getDiagnosticsProducingTypeChecker().getTypeCount(),
             getFileProcessingDiagnostics: () => fileProcessingDiagnostics,
-            getResolvedTypeReferenceDirectives: () => resolvedTypeReferenceDirectives
+            getResolvedTypeReferenceDirectives: () => resolvedTypeReferenceDirectives,
+            dropDiagnosticsProducingTypeChecker
         };
 
         verifyCompilerOptions();
@@ -1405,19 +608,23 @@ namespace ts {
             return diagnosticsProducingTypeChecker || (diagnosticsProducingTypeChecker = createTypeChecker(program, /*produceDiagnostics:*/ true));
         }
 
+        function dropDiagnosticsProducingTypeChecker() {
+            diagnosticsProducingTypeChecker = undefined;
+        }
+
         function getTypeChecker() {
             return noDiagnosticsTypeChecker || (noDiagnosticsTypeChecker = createTypeChecker(program, /*produceDiagnostics:*/ false));
         }
 
-        function emit(sourceFile?: SourceFile, writeFileCallback?: WriteFileCallback, cancellationToken?: CancellationToken): EmitResult {
-            return runWithCancellationToken(() => emitWorker(program, sourceFile, writeFileCallback, cancellationToken));
+        function emit(sourceFile?: SourceFile, writeFileCallback?: WriteFileCallback, cancellationToken?: CancellationToken, emitOnlyDtsFiles?: boolean): EmitResult {
+            return runWithCancellationToken(() => emitWorker(program, sourceFile, writeFileCallback, cancellationToken, emitOnlyDtsFiles));
         }
 
         function isEmitBlocked(emitFileName: string): boolean {
             return hasEmitBlockingDiagnostics.contains(toPath(emitFileName, currentDirectory, getCanonicalFileName));
         }
 
-        function emitWorker(program: Program, sourceFile: SourceFile, writeFileCallback: WriteFileCallback, cancellationToken: CancellationToken): EmitResult {
+        function emitWorker(program: Program, sourceFile: SourceFile, writeFileCallback: WriteFileCallback, cancellationToken: CancellationToken, emitOnlyDtsFiles?: boolean): EmitResult {
             let declarationDiagnostics: Diagnostic[] = [];
 
             if (options.noEmit) {
@@ -1462,7 +669,8 @@ namespace ts {
             const emitResult = emitFiles(
                 emitResolver,
                 getEmitHost(writeFileCallback),
-                sourceFile);
+                sourceFile,
+                emitOnlyDtsFiles);
 
             performance.mark("afterEmit");
             performance.measure("Emit", "beforeEmit", "afterEmit");
@@ -1710,7 +918,7 @@ namespace ts {
                     return false;
                 }
 
-                function checkModifiers(modifiers: ModifiersArray): boolean {
+                function checkModifiers(modifiers: NodeArray<Modifier>): boolean {
                     if (modifiers) {
                         for (const modifier of modifiers) {
                             switch (modifier.kind) {
@@ -1794,6 +1002,17 @@ namespace ts {
             let imports: LiteralExpression[];
             let moduleAugmentations: LiteralExpression[];
 
+            // If we are importing helpers, we need to add a synthetic reference to resolve the
+            // helpers library.
+            if (options.importHelpers
+                && (options.isolatedModules || isExternalModuleFile)
+                && !file.isDeclarationFile) {
+                const externalHelpersModuleReference = <StringLiteral>createNode(SyntaxKind.StringLiteral);
+                externalHelpersModuleReference.text = externalHelpersModuleNameText;
+                externalHelpersModuleReference.parent = file;
+                imports = [externalHelpersModuleReference];
+            }
+
             for (const node of file.statements) {
                 collectModuleReferences(node, /*inAmbientModule*/ false);
                 if (isJavaScriptFile) {
@@ -1827,7 +1046,7 @@ namespace ts {
                         }
                         break;
                     case SyntaxKind.ModuleDeclaration:
-                        if (isAmbientModule(<ModuleDeclaration>node) && (inAmbientModule || node.flags & NodeFlags.Ambient || isDeclarationFile(file))) {
+                        if (isAmbientModule(<ModuleDeclaration>node) && (inAmbientModule || hasModifier(node, ModifierFlags.Ambient) || isDeclarationFile(file))) {
                             const moduleName = <LiteralExpression>(<ModuleDeclaration>node).name;
                             // Ambient module declarations can be interpreted as augmentations for some existing external modules.
                             // This will happen in two cases:
@@ -2310,7 +1529,7 @@ namespace ts {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "emitDecoratorMetadata", "experimentalDecorators"));
             }
 
-            if (options.reactNamespace && !isIdentifier(options.reactNamespace, languageVersion)) {
+            if (options.reactNamespace && !isIdentifierText(options.reactNamespace, languageVersion)) {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Invalid_value_for_reactNamespace_0_is_not_a_valid_identifier, options.reactNamespace));
             }
 

src/compiler/scanner.ts

@@ -27,6 +27,7 @@ namespace ts {
         reScanSlashToken(): SyntaxKind;
         reScanTemplateToken(): SyntaxKind;
         scanJsxIdentifier(): SyntaxKind;
+        scanJsxAttributeValue(): SyntaxKind;
         reScanJsxToken(): SyntaxKind;
         scanJsxToken(): SyntaxKind;
         scanJSDocToken(): SyntaxKind;
@@ -439,9 +440,7 @@ namespace ts {
 
       /* @internal */
       export function skipTrivia(text: string, pos: number, stopAfterLineBreak?: boolean, stopAtComments = false): number {
-          // Using ! with a greater than test is a fast way of testing the following conditions:
-          //  pos === undefined || pos === null || isNaN(pos) || pos < 0;
-          if (!(pos >= 0)) {
+          if (positionIsSynthesized(pos)) {
               return pos;
           }
 
@@ -590,20 +589,34 @@ namespace ts {
     }
 
     /**
-     * Extract comments from text prefixing the token closest following `pos`.
-     * The return value is an array containing a TextRange for each comment.
-     * Single-line comment ranges include the beginning '//' characters but not the ending line break.
-     * Multi - line comment ranges include the beginning '/* and ending '<asterisk>/' characters.
-     * The return value is undefined if no comments were found.
-     * @param trailing
-     * If false, whitespace is skipped until the first line break and comments between that location
-     * and the next token are returned.
-     * If true, comments occurring between the given position and the next line break are returned.
+     * Invokes a callback for each comment range following the provided position.
+     *
+     * Single-line comment ranges include the leading double-slash characters but not the ending
+     * line break. Multi-line comment ranges include the leading slash-asterisk and trailing
+     * asterisk-slash characters.
+     *
+     * @param reduce If true, accumulates the result of calling the callback in a fashion similar
+     *      to reduceLeft. If false, iteration stops when the callback returns a truthy value.
+     * @param text The source text to scan.
+     * @param pos The position at which to start scanning.
+     * @param trailing If false, whitespace is skipped until the first line break and comments
+     *      between that location and the next token are returned. If true, comments occurring
+     *      between the given position and the next line break are returned.
+     * @param cb The callback to execute as each comment range is encountered.
+     * @param state A state value to pass to each iteration of the callback.
+     * @param initial An initial value to pass when accumulating results (when "reduce" is true).
+     * @returns If "reduce" is true, the accumulated value. If "reduce" is false, the first truthy
+     *      return value of the callback.
      */
-    function getCommentRanges(text: string, pos: number, trailing: boolean): CommentRange[] {
-        let result: CommentRange[];
+    function iterateCommentRanges<T, U>(reduce: boolean, text: string, pos: number, trailing: boolean, cb: (pos: number, end: number, kind: SyntaxKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial?: U): U {
+        let pendingPos: number;
+        let pendingEnd: number;
+        let pendingKind: SyntaxKind;
+        let pendingHasTrailingNewLine: boolean;
+        let hasPendingCommentRange = false;
         let collecting = trailing || pos === 0;
-        while (pos < text.length) {
+        let accumulator = initial;
+        scan: while (pos >= 0 && pos < text.length) {
             const ch = text.charCodeAt(pos);
             switch (ch) {
                 case CharacterCodes.carriageReturn:
@@ -613,12 +626,14 @@ namespace ts {
                 case CharacterCodes.lineFeed:
                     pos++;
                     if (trailing) {
-                        return result;
+                        break scan;
                     }
+
                     collecting = true;
-                    if (result && result.length) {
-                        lastOrUndefined(result).hasTrailingNewLine = true;
+                    if (hasPendingCommentRange) {
+                        pendingHasTrailingNewLine = true;
                     }
+
                     continue;
                 case CharacterCodes.tab:
                 case CharacterCodes.verticalTab:
@@ -651,38 +666,78 @@ namespace ts {
                                 pos++;
                             }
                         }
+
                         if (collecting) {
-                            if (!result) {
-                                result = [];
+                            if (hasPendingCommentRange) {
+                                accumulator = cb(pendingPos, pendingEnd, pendingKind, pendingHasTrailingNewLine, state, accumulator);
+                                if (!reduce && accumulator) {
+                                    // If we are not reducing and we have a truthy result, return it.
+                                    return accumulator;
+                                }
+
+                                hasPendingCommentRange = false;
                             }
 
-                            result.push({ pos: startPos, end: pos, hasTrailingNewLine, kind });
+                            pendingPos = startPos;
+                            pendingEnd = pos;
+                            pendingKind = kind;
+                            pendingHasTrailingNewLine = hasTrailingNewLine;
+                            hasPendingCommentRange = true;
                         }
+
                         continue;
                     }
-                    break;
+                    break scan;
                 default:
                     if (ch > CharacterCodes.maxAsciiCharacter && (isWhiteSpace(ch))) {
-                        if (result && result.length && isLineBreak(ch)) {
-                            lastOrUndefined(result).hasTrailingNewLine = true;
+                        if (hasPendingCommentRange && isLineBreak(ch)) {
+                            pendingHasTrailingNewLine = true;
                         }
                         pos++;
                         continue;
                     }
-                    break;
+                    break scan;
             }
-            return result;
         }
 
-        return result;
+        if (hasPendingCommentRange) {
+            accumulator = cb(pendingPos, pendingEnd, pendingKind, pendingHasTrailingNewLine, state, accumulator);
+        }
+
+        return accumulator;
+    }
+
+    export function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: SyntaxKind, hasTrailingNewLine: boolean, state: T) => U, state?: T) {
+        return iterateCommentRanges(/*reduce*/ false, text, pos, /*trailing*/ false, cb, state);
+    }
+
+    export function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: SyntaxKind, hasTrailingNewLine: boolean, state: T) => U, state?: T) {
+        return iterateCommentRanges(/*reduce*/ false, text, pos, /*trailing*/ true, cb, state);
+    }
+
+    export function reduceEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: SyntaxKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U) {
+        return iterateCommentRanges(/*reduce*/ true, text, pos, /*trailing*/ false, cb, state, initial);
+    }
+
+    export function reduceEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: SyntaxKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U) {
+        return iterateCommentRanges(/*reduce*/ true, text, pos, /*trailing*/ true, cb, state, initial);
+    }
+
+    function appendCommentRange(pos: number, end: number, kind: SyntaxKind, hasTrailingNewLine: boolean, state: any, comments: CommentRange[]) {
+        if (!comments) {
+            comments = [];
+        }
+
+        comments.push({ pos, end, hasTrailingNewLine, kind });
+        return comments;
     }
 
     export function getLeadingCommentRanges(text: string, pos: number): CommentRange[] {
-        return getCommentRanges(text, pos, /*trailing*/ false);
+        return reduceEachLeadingCommentRange(text, pos, appendCommentRange, undefined, undefined);
     }
 
     export function getTrailingCommentRanges(text: string, pos: number): CommentRange[] {
-        return getCommentRanges(text, pos, /*trailing*/ true);
+        return reduceEachTrailingCommentRange(text, pos, appendCommentRange, undefined, undefined);
     }
 
     /** Optionally, get the shebang */
@@ -705,7 +760,7 @@ namespace ts {
     }
 
     /* @internal */
-    export function isIdentifier(name: string, languageVersion: ScriptTarget): boolean {
+    export function isIdentifierText(name: string, languageVersion: ScriptTarget): boolean {
         if (!isIdentifierStart(name.charCodeAt(0), languageVersion)) {
             return false;
         }
@@ -763,6 +818,7 @@ namespace ts {
             reScanSlashToken,
             reScanTemplateToken,
             scanJsxIdentifier,
+            scanJsxAttributeValue,
             reScanJsxToken,
             scanJsxToken,
             scanJSDocToken,
@@ -857,7 +913,7 @@ namespace ts {
             return value;
         }
 
-        function scanString(): string {
+        function scanString(allowEscapes = true): string {
             const quote = text.charCodeAt(pos);
             pos++;
             let result = "";
@@ -875,7 +931,7 @@ namespace ts {
                     pos++;
                     break;
                 }
-                if (ch === CharacterCodes.backslash) {
+                if (ch === CharacterCodes.backslash && allowEscapes) {
                     result += text.substring(start, pos);
                     result += scanEscapeSequence();
                     start = pos;
@@ -1683,46 +1739,66 @@ namespace ts {
             return token;
         }
 
+        function scanJsxAttributeValue(): SyntaxKind {
+            startPos = pos;
+
+            switch (text.charCodeAt(pos)) {
+                case CharacterCodes.doubleQuote:
+                case CharacterCodes.singleQuote:
+                    tokenValue = scanString(/*allowEscapes*/ false);
+                    return token = SyntaxKind.StringLiteral;
+                default:
+                    // If this scans anything other than `{`, it's a parse error.
+                    return scan();
+            }
+        }
+
         function scanJSDocToken(): SyntaxKind {
             if (pos >= end) {
                 return token = SyntaxKind.EndOfFileToken;
             }
 
             startPos = pos;
-
-            // Eat leading whitespace
-            let ch = text.charCodeAt(pos);
-            while (pos < end) {
-                ch = text.charCodeAt(pos);
-                if (isWhiteSpaceSingleLine(ch)) {
-                    pos++;
-                }
-                else {
-                    break;
-                }
-            }
             tokenPos = pos;
 
+            const ch = text.charCodeAt(pos);
             switch (ch) {
+                case CharacterCodes.tab:
+                case CharacterCodes.verticalTab:
+                case CharacterCodes.formFeed:
+                case CharacterCodes.space:
+                    while (pos < end && isWhiteSpaceSingleLine(text.charCodeAt(pos))) {
+                        pos++;
+                    }
+                    return token = SyntaxKind.WhitespaceTrivia;
                 case CharacterCodes.at:
-                    return pos += 1, token = SyntaxKind.AtToken;
+                    pos++;
+                    return token = SyntaxKind.AtToken;
                 case CharacterCodes.lineFeed:
                 case CharacterCodes.carriageReturn:
-                    return pos += 1, token = SyntaxKind.NewLineTrivia;
+                    pos++;
+                    return token = SyntaxKind.NewLineTrivia;
                 case CharacterCodes.asterisk:
-                    return pos += 1, token = SyntaxKind.AsteriskToken;
+                    pos++;
+                    return token = SyntaxKind.AsteriskToken;
                 case CharacterCodes.openBrace:
-                    return pos += 1, token = SyntaxKind.OpenBraceToken;
+                    pos++;
+                    return token = SyntaxKind.OpenBraceToken;
                 case CharacterCodes.closeBrace:
-                    return pos += 1, token = SyntaxKind.CloseBraceToken;
+                    pos++;
+                    return token = SyntaxKind.CloseBraceToken;
                 case CharacterCodes.openBracket:
-                    return pos += 1, token = SyntaxKind.OpenBracketToken;
+                    pos++;
+                    return token = SyntaxKind.OpenBracketToken;
                 case CharacterCodes.closeBracket:
-                    return pos += 1, token = SyntaxKind.CloseBracketToken;
+                    pos++;
+                    return token = SyntaxKind.CloseBracketToken;
                 case CharacterCodes.equals:
-                    return pos += 1, token = SyntaxKind.EqualsToken;
+                    pos++;
+                    return token = SyntaxKind.EqualsToken;
                 case CharacterCodes.comma:
-                    return pos += 1, token = SyntaxKind.CommaToken;
+                    pos++;
+                    return token = SyntaxKind.CommaToken;
             }
 
             if (isIdentifierStart(ch, ScriptTarget.Latest)) {

src/compiler/sourcemap.ts

@@ -3,19 +3,73 @@
 /* @internal */
 namespace ts {
     export interface SourceMapWriter {
-        getSourceMapData(): SourceMapData;
-        setSourceFile(sourceFile: SourceFile): void;
-        emitPos(pos: number): void;
-        emitStart(range: TextRange): void;
-        emitEnd(range: TextRange, stopOverridingSpan?: boolean): void;
-        changeEmitSourcePos(): void;
-        getText(): string;
-        getSourceMappingURL(): string;
+        /**
+         * Initialize the SourceMapWriter for a new output file.
+         *
+         * @param filePath The path to the generated output file.
+         * @param sourceMapFilePath The path to the output source map file.
+         * @param sourceFiles The input source files for the program.
+         * @param isBundledEmit A value indicating whether the generated output file is a bundle.
+         */
         initialize(filePath: string, sourceMapFilePath: string, sourceFiles: SourceFile[], isBundledEmit: boolean): void;
+
+        /**
+         * Reset the SourceMapWriter to an empty state.
+         */
         reset(): void;
+
+        /**
+         * Set the current source file.
+         *
+         * @param sourceFile The source file.
+         */
+        setSourceFile(sourceFile: SourceFile): void;
+
+        /**
+         * Emits a mapping.
+         *
+         * If the position is synthetic (undefined or a negative value), no mapping will be
+         * created.
+         *
+         * @param pos The position.
+         */
+        emitPos(pos: number): void;
+
+        /**
+         * Emits a node with possible leading and trailing source maps.
+         *
+         * @param emitContext The current emit context
+         * @param node The node to emit.
+         * @param emitCallback The callback used to emit the node.
+         */
+        emitNodeWithSourceMap(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void): void;
+
+        /**
+         * Emits a token of a node node with possible leading and trailing source maps.
+         *
+         * @param node The node containing the token.
+         * @param token The token to emit.
+         * @param tokenStartPos The start pos of the token.
+         * @param emitCallback The callback used to emit the token.
+         */
+        emitTokenWithSourceMap(node: Node, token: SyntaxKind, tokenStartPos: number, emitCallback: (token: SyntaxKind, tokenStartPos: number) => number): number;
+
+        /**
+         * Gets the text for the source map.
+         */
+        getText(): string;
+
+        /**
+         * Gets the SourceMappingURL for the source map.
+         */
+        getSourceMappingURL(): string;
+
+        /**
+         * Gets test data for source maps.
+         */
+        getSourceMapData(): SourceMapData;
     }
 
-    let nullSourceMapWriter: SourceMapWriter;
     // Used for initialize lastEncodedSourceMapSpan and reset lastEncodedSourceMapSpan when updateLastEncodedAndRecordedSpans
     const defaultLastEncodedSourceMapSpan: SourceMapSpan = {
         emittedLine: 1,
@@ -25,32 +79,12 @@ namespace ts {
         sourceIndex: 0
     };
 
-    export function getNullSourceMapWriter(): SourceMapWriter {
-        if (nullSourceMapWriter === undefined) {
-            nullSourceMapWriter = {
-                getSourceMapData(): SourceMapData { return undefined; },
-                setSourceFile(sourceFile: SourceFile): void { },
-                emitStart(range: TextRange): void { },
-                emitEnd(range: TextRange, stopOverridingSpan?: boolean): void { },
-                emitPos(pos: number): void { },
-                changeEmitSourcePos(): void { },
-                getText(): string { return undefined; },
-                getSourceMappingURL(): string { return undefined; },
-                initialize(filePath: string, sourceMapFilePath: string, sourceFiles: SourceFile[], isBundledEmit: boolean): void { },
-                reset(): void { },
-            };
-        }
-
-        return nullSourceMapWriter;
-    }
-
     export function createSourceMapWriter(host: EmitHost, writer: EmitTextWriter): SourceMapWriter {
         const compilerOptions = host.getCompilerOptions();
         const extendedDiagnostics = compilerOptions.extendedDiagnostics;
         let currentSourceFile: SourceFile;
+        let currentSourceText: string;
         let sourceMapDir: string; // The directory in which sourcemap will be
-        let stopOverridingSpan = false;
-        let modifyLastSourcePos = false;
 
         // Current source map file and its index in the sources list
         let sourceMapSourceIndex: number;
@@ -62,26 +96,39 @@ namespace ts {
 
         // Source map data
         let sourceMapData: SourceMapData;
+        let disabled: boolean = !(compilerOptions.sourceMap || compilerOptions.inlineSourceMap);
 
         return {
+            initialize,
+            reset,
             getSourceMapData: () => sourceMapData,
             setSourceFile,
             emitPos,
-            emitStart,
-            emitEnd,
-            changeEmitSourcePos,
+            emitNodeWithSourceMap,
+            emitTokenWithSourceMap,
             getText,
             getSourceMappingURL,
-            initialize,
-            reset,
         };
 
+        /**
+         * Initialize the SourceMapWriter for a new output file.
+         *
+         * @param filePath The path to the generated output file.
+         * @param sourceMapFilePath The path to the output source map file.
+         * @param sourceFiles The input source files for the program.
+         * @param isBundledEmit A value indicating whether the generated output file is a bundle.
+         */
         function initialize(filePath: string, sourceMapFilePath: string, sourceFiles: SourceFile[], isBundledEmit: boolean) {
+            if (disabled) {
+                return;
+            }
+
             if (sourceMapData) {
                 reset();
             }
 
             currentSourceFile = undefined;
+            currentSourceText = undefined;
 
             // Current source map file and its index in the sources list
             sourceMapSourceIndex = -1;
@@ -140,7 +187,14 @@ namespace ts {
             }
         }
 
+        /**
+         * Reset the SourceMapWriter to an empty state.
+         */
         function reset() {
+            if (disabled) {
+                return;
+            }
+
             currentSourceFile = undefined;
             sourceMapDir = undefined;
             sourceMapSourceIndex = undefined;
@@ -150,47 +204,6 @@ namespace ts {
             sourceMapData = undefined;
         }
 
-        function updateLastEncodedAndRecordedSpans() {
-            if (modifyLastSourcePos) {
-                // Reset the source pos
-                modifyLastSourcePos = false;
-
-                // Change Last recorded Map with last encoded emit line and character
-                lastRecordedSourceMapSpan.emittedLine = lastEncodedSourceMapSpan.emittedLine;
-                lastRecordedSourceMapSpan.emittedColumn = lastEncodedSourceMapSpan.emittedColumn;
-
-                // Pop sourceMapDecodedMappings to remove last entry
-                sourceMapData.sourceMapDecodedMappings.pop();
-
-                // Point the lastEncodedSourceMapSpace to the previous encoded sourceMapSpan
-                // If the list is empty which indicates that we are at the beginning of the file,
-                // we have to reset it to default value (same value when we first initialize sourceMapWriter)
-                lastEncodedSourceMapSpan = sourceMapData.sourceMapDecodedMappings.length ?
-                    sourceMapData.sourceMapDecodedMappings[sourceMapData.sourceMapDecodedMappings.length - 1] :
-                    defaultLastEncodedSourceMapSpan;
-
-                // TODO: Update lastEncodedNameIndex
-                // Since we dont support this any more, lets not worry about it right now.
-                // When we start supporting nameIndex, we will get back to this
-
-                // Change the encoded source map
-                const sourceMapMappings = sourceMapData.sourceMapMappings;
-                let lenthToSet = sourceMapMappings.length - 1;
-                for (; lenthToSet >= 0; lenthToSet--) {
-                    const currentChar = sourceMapMappings.charAt(lenthToSet);
-                    if (currentChar === ",") {
-                        // Separator for the entry found
-                        break;
-                    }
-                    if (currentChar === ";" && lenthToSet !== 0 && sourceMapMappings.charAt(lenthToSet - 1) !== ";") {
-                        // Last line separator found
-                        break;
-                    }
-                }
-                sourceMapData.sourceMapMappings = sourceMapMappings.substr(0, Math.max(0, lenthToSet));
-            }
-        }
-
         // Encoding for sourcemap span
         function encodeLastRecordedSourceMapSpan() {
             if (!lastRecordedSourceMapSpan || lastRecordedSourceMapSpan === lastEncodedSourceMapSpan) {
@@ -236,8 +249,16 @@ namespace ts {
             sourceMapData.sourceMapDecodedMappings.push(lastEncodedSourceMapSpan);
         }
 
+        /**
+         * Emits a mapping.
+         *
+         * If the position is synthetic (undefined or a negative value), no mapping will be
+         * created.
+         *
+         * @param pos The position.
+         */
         function emitPos(pos: number) {
-            if (pos === -1) {
+            if (disabled || positionIsSynthesized(pos)) {
                 return;
             }
 
@@ -273,45 +294,103 @@ namespace ts {
                     sourceColumn: sourceLinePos.character,
                     sourceIndex: sourceMapSourceIndex
                 };
-
-                stopOverridingSpan = false;
             }
-            else if (!stopOverridingSpan) {
+            else {
                 // Take the new pos instead since there is no change in emittedLine and column since last location
                 lastRecordedSourceMapSpan.sourceLine = sourceLinePos.line;
                 lastRecordedSourceMapSpan.sourceColumn = sourceLinePos.character;
                 lastRecordedSourceMapSpan.sourceIndex = sourceMapSourceIndex;
             }
 
-            updateLastEncodedAndRecordedSpans();
-
             if (extendedDiagnostics) {
                 performance.mark("afterSourcemap");
                 performance.measure("Source Map", "beforeSourcemap", "afterSourcemap");
             }
         }
 
-        function getStartPos(range: TextRange) {
-            const rangeHasDecorators = !!(range as Node).decorators;
-            return range.pos !== -1 ? skipTrivia(currentSourceFile.text, rangeHasDecorators ? (range as Node).decorators.end : range.pos) : -1;
+        /**
+         * Emits a node with possible leading and trailing source maps.
+         *
+         * @param node The node to emit.
+         * @param emitCallback The callback used to emit the node.
+         */
+        function emitNodeWithSourceMap(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void) {
+            if (disabled) {
+                return emitCallback(emitContext, node);
+            }
+
+            if (node) {
+                const emitNode = node.emitNode;
+                const emitFlags = emitNode && emitNode.flags;
+                const { pos, end } = emitNode && emitNode.sourceMapRange || node;
+
+                if (node.kind !== SyntaxKind.NotEmittedStatement
+                    && (emitFlags & EmitFlags.NoLeadingSourceMap) === 0
+                    && pos >= 0) {
+                    emitPos(skipTrivia(currentSourceText, pos));
+                }
+
+                if (emitFlags & EmitFlags.NoNestedSourceMaps) {
+                    disabled = true;
+                    emitCallback(emitContext, node);
+                    disabled = false;
+                }
+                else {
+                    emitCallback(emitContext, node);
+                }
+
+                if (node.kind !== SyntaxKind.NotEmittedStatement
+                    && (emitFlags & EmitFlags.NoTrailingSourceMap) === 0
+                    && end >= 0) {
+                    emitPos(end);
+                }
+            }
         }
 
-        function emitStart(range: TextRange) {
-            emitPos(getStartPos(range));
-        }
-
-        function emitEnd(range: TextRange, stopOverridingEnd?: boolean) {
-            emitPos(range.end);
-            stopOverridingSpan = stopOverridingEnd;
-        }
-
-        function changeEmitSourcePos() {
-            Debug.assert(!modifyLastSourcePos);
-            modifyLastSourcePos = true;
+        /**
+         * Emits a token of a node with possible leading and trailing source maps.
+         *
+         * @param node The node containing the token.
+         * @param token The token to emit.
+         * @param tokenStartPos The start pos of the token.
+         * @param emitCallback The callback used to emit the token.
+         */
+        function emitTokenWithSourceMap(node: Node, token: SyntaxKind, tokenPos: number, emitCallback: (token: SyntaxKind, tokenStartPos: number) => number) {
+            if (disabled) {
+                return emitCallback(token, tokenPos);
+            }
+
+            const emitNode = node && node.emitNode;
+            const emitFlags = emitNode && emitNode.flags;
+            const range = emitNode && emitNode.tokenSourceMapRanges && emitNode.tokenSourceMapRanges[token];
+
+            tokenPos = skipTrivia(currentSourceText, range ? range.pos : tokenPos);
+            if ((emitFlags & EmitFlags.NoTokenLeadingSourceMaps) === 0 && tokenPos >= 0) {
+                emitPos(tokenPos);
+            }
+
+            tokenPos = emitCallback(token, tokenPos);
+
+            if (range) tokenPos = range.end;
+            if ((emitFlags & EmitFlags.NoTokenTrailingSourceMaps) === 0 && tokenPos >= 0) {
+                emitPos(tokenPos);
+            }
+
+            return tokenPos;
         }
 
+        /**
+         * Set the current source file.
+         *
+         * @param sourceFile The source file.
+         */
         function setSourceFile(sourceFile: SourceFile) {
+            if (disabled) {
+                return;
+            }
+
             currentSourceFile = sourceFile;
+            currentSourceText = currentSourceFile.text;
 
             // Add the file to tsFilePaths
             // If sourceroot option: Use the relative path corresponding to the common directory path
@@ -330,15 +409,22 @@ namespace ts {
                 sourceMapData.sourceMapSources.push(source);
 
                 // The one that can be used from program to get the actual source file
-                sourceMapData.inputSourceFileNames.push(sourceFile.fileName);
+                sourceMapData.inputSourceFileNames.push(currentSourceFile.fileName);
 
                 if (compilerOptions.inlineSources) {
-                    sourceMapData.sourceMapSourcesContent.push(sourceFile.text);
+                    sourceMapData.sourceMapSourcesContent.push(currentSourceFile.text);
                 }
             }
         }
 
+        /**
+         * Gets the text for the source map.
+         */
         function getText() {
+            if (disabled) {
+                return;
+            }
+
             encodeLastRecordedSourceMapSpan();
 
             return stringify({
@@ -352,7 +438,14 @@ namespace ts {
             });
         }
 
+        /**
+         * Gets the SourceMappingURL for the source map.
+         */
         function getSourceMappingURL() {
+            if (disabled) {
+                return;
+            }
+
             if (compilerOptions.inlineSourceMap) {
                 // Encode the sourceMap into the sourceMap url
                 const base64SourceMapText = convertToBase64(getText());

src/compiler/sys.ts

@@ -32,6 +32,8 @@ namespace ts {
         getMemoryUsage?(): number;
         exit(exitCode?: number): void;
         realpath?(path: string): string;
+        /*@internal*/ getEnvironmentVariable(name: string): string;
+        /*@internal*/ tryEnableSourceMapsForHost?(): void;
     }
 
     export interface FileWatcher {
@@ -78,6 +80,7 @@ namespace ts {
         watchFile?(path: string, callback: FileWatcherCallback): FileWatcher;
         watchDirectory?(path: string, callback: DirectoryWatcherCallback, recursive?: boolean): FileWatcher;
         realpath(path: string): string;
+        getEnvironmentVariable?(name: string): string;
     };
 
     export var sys: System = (function() {
@@ -212,6 +215,9 @@ namespace ts {
                     return shell.CurrentDirectory;
                 },
                 getDirectories,
+                getEnvironmentVariable(name: string) {
+                    return new ActiveXObject("WScript.Shell").ExpandEnvironmentStrings(`%${name}%`);
+                },
                 readDirectory,
                 exit(exitCode?: number): void {
                     try {
@@ -267,7 +273,7 @@ namespace ts {
                 }
 
                 function addFileWatcherCallback(filePath: string, callback: FileWatcherCallback): void {
-                    (fileWatcherCallbacks[filePath] || (fileWatcherCallbacks[filePath] = [])).push(callback);
+                    multiMapAdd(fileWatcherCallbacks, filePath, callback);
                 }
 
                 function addFile(fileName: string, callback: FileWatcherCallback): WatchedFile {
@@ -283,16 +289,7 @@ namespace ts {
                 }
 
                 function removeFileWatcherCallback(filePath: string, callback: FileWatcherCallback) {
-                    const callbacks = fileWatcherCallbacks[filePath];
-                    if (callbacks) {
-                        const newCallbacks = copyListRemovingItem(callback, callbacks);
-                        if (newCallbacks.length === 0) {
-                            delete fileWatcherCallbacks[filePath];
-                        }
-                        else {
-                            fileWatcherCallbacks[filePath] = newCallbacks;
-                        }
-                    }
+                    multiMapRemove(fileWatcherCallbacks, filePath, callback);
                 }
 
                 function fileEventHandler(eventName: string, relativeFileName: string, baseDirPath: string) {
@@ -432,7 +429,7 @@ namespace ts {
             }
 
             function getDirectories(path: string): string[] {
-                return filter<string>(_fs.readdirSync(path), p => fileSystemEntryExists(combinePaths(path, p), FileSystemEntryKind.Directory));
+                return filter<string>(_fs.readdirSync(path), dir => fileSystemEntryExists(combinePaths(path, dir), FileSystemEntryKind.Directory));
             }
 
             const nodeSystem: System = {
@@ -508,6 +505,9 @@ namespace ts {
                     return process.cwd();
                 },
                 getDirectories,
+                getEnvironmentVariable(name: string) {
+                    return process.env[name] || "";
+                },
                 readDirectory,
                 getModifiedTime(path) {
                     try {
@@ -543,6 +543,14 @@ namespace ts {
                 },
                 realpath(path: string): string {
                     return _fs.realpathSync(path);
+                },
+                tryEnableSourceMapsForHost() {
+                    try {
+                        require("source-map-support").install();
+                    }
+                    catch (e) {
+                        // Could not enable source maps.
+                    }
                 }
             };
             return nodeSystem;
@@ -574,6 +582,7 @@ namespace ts {
                 getExecutingFilePath: () => ChakraHost.executingFile,
                 getCurrentDirectory: () => ChakraHost.currentDirectory,
                 getDirectories: ChakraHost.getDirectories,
+                getEnvironmentVariable: ChakraHost.getEnvironmentVariable || ((name: string) => ""),
                 readDirectory: (path: string, extensions?: string[], excludes?: string[], includes?: string[]) => {
                     const pattern = getFileMatcherPatterns(path, extensions, excludes, includes, !!ChakraHost.useCaseSensitiveFileNames, ChakraHost.currentDirectory);
                     return ChakraHost.readDirectory(path, extensions, pattern.basePaths, pattern.excludePattern, pattern.includeFilePattern, pattern.includeDirectoryPattern);
@@ -583,19 +592,40 @@ namespace ts {
             };
         }
 
+        function recursiveCreateDirectory(directoryPath: string, sys: System) {
+            const basePath = getDirectoryPath(directoryPath);
+            const shouldCreateParent = directoryPath !== basePath && !sys.directoryExists(basePath);
+            if (shouldCreateParent) {
+                recursiveCreateDirectory(basePath, sys);
+            }
+            if (shouldCreateParent || !sys.directoryExists(directoryPath)) {
+                sys.createDirectory(directoryPath);
+            }
+        }
+
+        let sys: System;
         if (typeof ChakraHost !== "undefined") {
-            return getChakraSystem();
+            sys = getChakraSystem();
         }
         else if (typeof WScript !== "undefined" && typeof ActiveXObject === "function") {
-            return getWScriptSystem();
+            sys = getWScriptSystem();
         }
         else if (typeof process !== "undefined" && process.nextTick && !process.browser && typeof require !== "undefined") {
             // process and process.nextTick checks if current environment is node-like
             // process.browser check excludes webpack and browserify
-            return getNodeSystem();
+            sys = getNodeSystem();
         }
-        else {
-            return undefined; // Unsupported host
+        if (sys) {
+            // patch writefile to create folder before writing the file
+            const originalWriteFile = sys.writeFile;
+            sys.writeFile = function(path, data, writeBom) {
+                const directoryPath = getDirectoryPath(normalizeSlashes(path));
+                if (directoryPath && !sys.directoryExists(directoryPath)) {
+                    recursiveCreateDirectory(directoryPath, sys);
+                }
+                originalWriteFile.call(sys, path, data, writeBom);
+            };
         }
+        return sys;
     })();
 }

src/compiler/transformer.ts

@@ -0,0 +1,342 @@
+/// <reference path="visitor.ts" />
+/// <reference path="transformers/ts.ts" />
+/// <reference path="transformers/jsx.ts" />
+/// <reference path="transformers/es7.ts" />
+/// <reference path="transformers/es6.ts" />
+/// <reference path="transformers/generators.ts" />
+/// <reference path="transformers/module/module.ts" />
+/// <reference path="transformers/module/system.ts" />
+/// <reference path="transformers/module/es6.ts" />
+
+/* @internal */
+namespace ts {
+    const moduleTransformerMap = createMap<Transformer>({
+        [ModuleKind.ES6]: transformES6Module,
+        [ModuleKind.System]: transformSystemModule,
+        [ModuleKind.AMD]: transformModule,
+        [ModuleKind.CommonJS]: transformModule,
+        [ModuleKind.UMD]: transformModule,
+        [ModuleKind.None]: transformModule,
+    });
+
+    const enum SyntaxKindFeatureFlags {
+        Substitution = 1 << 0,
+        EmitNotifications = 1 << 1,
+    }
+
+    export interface TransformationResult {
+        /**
+         * Gets the transformed source files.
+         */
+        transformed: SourceFile[];
+
+        /**
+         * Emits the substitute for a node, if one is available; otherwise, emits the node.
+         *
+         * @param emitContext The current emit context.
+         * @param node The node to substitute.
+         * @param emitCallback A callback used to emit the node or its substitute.
+         */
+        emitNodeWithSubstitution(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void): void;
+
+        /**
+         * Emits a node with possible notification.
+         *
+         * @param emitContext The current emit context.
+         * @param node The node to emit.
+         * @param emitCallback A callback used to emit the node.
+         */
+        emitNodeWithNotification(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void): void;
+    }
+
+    export interface TransformationContext extends LexicalEnvironment {
+        getCompilerOptions(): CompilerOptions;
+        getEmitResolver(): EmitResolver;
+        getEmitHost(): EmitHost;
+
+        /**
+         * Hoists a function declaration to the containing scope.
+         */
+        hoistFunctionDeclaration(node: FunctionDeclaration): void;
+
+        /**
+         * Hoists a variable declaration to the containing scope.
+         */
+        hoistVariableDeclaration(node: Identifier): void;
+
+        /**
+         * Enables expression substitutions in the pretty printer for the provided SyntaxKind.
+         */
+        enableSubstitution(kind: SyntaxKind): void;
+
+        /**
+         * Determines whether expression substitutions are enabled for the provided node.
+         */
+        isSubstitutionEnabled(node: Node): boolean;
+
+        /**
+         * Hook used by transformers to substitute expressions just before they
+         * are emitted by the pretty printer.
+         */
+        onSubstituteNode?: (emitContext: EmitContext, node: Node) => Node;
+
+        /**
+         * Enables before/after emit notifications in the pretty printer for the provided
+         * SyntaxKind.
+         */
+        enableEmitNotification(kind: SyntaxKind): void;
+
+        /**
+         * Determines whether before/after emit notifications should be raised in the pretty
+         * printer when it emits a node.
+         */
+        isEmitNotificationEnabled(node: Node): boolean;
+
+        /**
+         * Hook used to allow transformers to capture state before or after
+         * the printer emits a node.
+         */
+        onEmitNode?: (emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void) => void;
+    }
+
+    /* @internal */
+    export type Transformer = (context: TransformationContext) => (node: SourceFile) => SourceFile;
+
+    export function getTransformers(compilerOptions: CompilerOptions) {
+        const jsx = compilerOptions.jsx;
+        const languageVersion = getEmitScriptTarget(compilerOptions);
+        const moduleKind = getEmitModuleKind(compilerOptions);
+        const transformers: Transformer[] = [];
+
+        transformers.push(transformTypeScript);
+        transformers.push(moduleTransformerMap[moduleKind] || moduleTransformerMap[ModuleKind.None]);
+
+        if (jsx === JsxEmit.React) {
+            transformers.push(transformJsx);
+        }
+
+        transformers.push(transformES7);
+
+        if (languageVersion < ScriptTarget.ES6) {
+            transformers.push(transformES6);
+            transformers.push(transformGenerators);
+        }
+
+        return transformers;
+    }
+
+    /**
+     * Transforms an array of SourceFiles by passing them through each transformer.
+     *
+     * @param resolver The emit resolver provided by the checker.
+     * @param host The emit host.
+     * @param sourceFiles An array of source files
+     * @param transforms An array of Transformers.
+     */
+    export function transformFiles(resolver: EmitResolver, host: EmitHost, sourceFiles: SourceFile[], transformers: Transformer[]): TransformationResult {
+        const lexicalEnvironmentVariableDeclarationsStack: VariableDeclaration[][] = [];
+        const lexicalEnvironmentFunctionDeclarationsStack: FunctionDeclaration[][] = [];
+        const enabledSyntaxKindFeatures = new Array<SyntaxKindFeatureFlags>(SyntaxKind.Count);
+
+        let lexicalEnvironmentStackOffset = 0;
+        let hoistedVariableDeclarations: VariableDeclaration[];
+        let hoistedFunctionDeclarations: FunctionDeclaration[];
+        let lexicalEnvironmentDisabled: boolean;
+
+        // The transformation context is provided to each transformer as part of transformer
+        // initialization.
+        const context: TransformationContext = {
+            getCompilerOptions: () => host.getCompilerOptions(),
+            getEmitResolver: () => resolver,
+            getEmitHost: () => host,
+            hoistVariableDeclaration,
+            hoistFunctionDeclaration,
+            startLexicalEnvironment,
+            endLexicalEnvironment,
+            onSubstituteNode: (emitContext, node) => node,
+            enableSubstitution,
+            isSubstitutionEnabled,
+            onEmitNode: (node, emitContext, emitCallback) => emitCallback(node, emitContext),
+            enableEmitNotification,
+            isEmitNotificationEnabled
+        };
+
+        // Chain together and initialize each transformer.
+        const transformation = chain(...transformers)(context);
+
+        // Transform each source file.
+        const transformed = map(sourceFiles, transformSourceFile);
+
+        // Disable modification of the lexical environment.
+        lexicalEnvironmentDisabled = true;
+
+        return {
+            transformed,
+            emitNodeWithSubstitution,
+            emitNodeWithNotification
+        };
+
+        /**
+         * Transforms a source file.
+         *
+         * @param sourceFile The source file to transform.
+         */
+        function transformSourceFile(sourceFile: SourceFile) {
+            if (isDeclarationFile(sourceFile)) {
+                return sourceFile;
+            }
+
+            return transformation(sourceFile);
+        }
+
+        /**
+         * Enables expression substitutions in the pretty printer for the provided SyntaxKind.
+         */
+        function enableSubstitution(kind: SyntaxKind) {
+            enabledSyntaxKindFeatures[kind] |= SyntaxKindFeatureFlags.Substitution;
+        }
+
+        /**
+         * Determines whether expression substitutions are enabled for the provided node.
+         */
+        function isSubstitutionEnabled(node: Node) {
+            return (enabledSyntaxKindFeatures[node.kind] & SyntaxKindFeatureFlags.Substitution) !== 0
+                && (getEmitFlags(node) & EmitFlags.NoSubstitution) === 0;
+        }
+
+        /**
+         * Emits a node with possible substitution.
+         *
+         * @param emitContext The current emit context.
+         * @param node The node to emit.
+         * @param emitCallback The callback used to emit the node or its substitute.
+         */
+        function emitNodeWithSubstitution(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void) {
+            if (node) {
+                if (isSubstitutionEnabled(node)) {
+                    const substitute = context.onSubstituteNode(emitContext, node);
+                    if (substitute && substitute !== node) {
+                        emitCallback(emitContext, substitute);
+                        return;
+                    }
+                }
+
+                emitCallback(emitContext, node);
+            }
+        }
+
+        /**
+         * Enables before/after emit notifications in the pretty printer for the provided SyntaxKind.
+         */
+        function enableEmitNotification(kind: SyntaxKind) {
+            enabledSyntaxKindFeatures[kind] |= SyntaxKindFeatureFlags.EmitNotifications;
+        }
+
+        /**
+         * Determines whether before/after emit notifications should be raised in the pretty
+         * printer when it emits a node.
+         */
+        function isEmitNotificationEnabled(node: Node) {
+            return (enabledSyntaxKindFeatures[node.kind] & SyntaxKindFeatureFlags.EmitNotifications) !== 0
+                || (getEmitFlags(node) & EmitFlags.AdviseOnEmitNode) !== 0;
+        }
+
+        /**
+         * Emits a node with possible emit notification.
+         *
+         * @param emitContext The current emit context.
+         * @param node The node to emit.
+         * @param emitCallback The callback used to emit the node.
+         */
+        function emitNodeWithNotification(emitContext: EmitContext, node: Node, emitCallback: (emitContext: EmitContext, node: Node) => void) {
+            if (node) {
+                if (isEmitNotificationEnabled(node)) {
+                    context.onEmitNode(emitContext, node, emitCallback);
+                }
+                else {
+                    emitCallback(emitContext, node);
+                }
+            }
+        }
+
+        /**
+         * Records a hoisted variable declaration for the provided name within a lexical environment.
+         */
+        function hoistVariableDeclaration(name: Identifier): void {
+            Debug.assert(!lexicalEnvironmentDisabled, "Cannot modify the lexical environment during the print phase.");
+            const decl = createVariableDeclaration(name);
+            if (!hoistedVariableDeclarations) {
+                hoistedVariableDeclarations = [decl];
+            }
+            else {
+                hoistedVariableDeclarations.push(decl);
+            }
+        }
+
+        /**
+         * Records a hoisted function declaration within a lexical environment.
+         */
+        function hoistFunctionDeclaration(func: FunctionDeclaration): void {
+            Debug.assert(!lexicalEnvironmentDisabled, "Cannot modify the lexical environment during the print phase.");
+            if (!hoistedFunctionDeclarations) {
+                hoistedFunctionDeclarations = [func];
+            }
+            else {
+                hoistedFunctionDeclarations.push(func);
+            }
+        }
+
+        /**
+         * Starts a new lexical environment. Any existing hoisted variable or function declarations
+         * are pushed onto a stack, and the related storage variables are reset.
+         */
+        function startLexicalEnvironment(): void {
+            Debug.assert(!lexicalEnvironmentDisabled, "Cannot start a lexical environment during the print phase.");
+
+            // Save the current lexical environment. Rather than resizing the array we adjust the
+            // stack size variable. This allows us to reuse existing array slots we've
+            // already allocated between transformations to avoid allocation and GC overhead during
+            // transformation.
+            lexicalEnvironmentVariableDeclarationsStack[lexicalEnvironmentStackOffset] = hoistedVariableDeclarations;
+            lexicalEnvironmentFunctionDeclarationsStack[lexicalEnvironmentStackOffset] = hoistedFunctionDeclarations;
+            lexicalEnvironmentStackOffset++;
+            hoistedVariableDeclarations = undefined;
+            hoistedFunctionDeclarations = undefined;
+        }
+
+        /**
+         * Ends a lexical environment. The previous set of hoisted declarations are restored and
+         * any hoisted declarations added in this environment are returned.
+         */
+        function endLexicalEnvironment(): Statement[] {
+            Debug.assert(!lexicalEnvironmentDisabled, "Cannot end a lexical environment during the print phase.");
+
+            let statements: Statement[];
+            if (hoistedVariableDeclarations || hoistedFunctionDeclarations) {
+                if (hoistedFunctionDeclarations) {
+                    statements = [...hoistedFunctionDeclarations];
+                }
+
+                if (hoistedVariableDeclarations) {
+                    const statement = createVariableStatement(
+                        /*modifiers*/ undefined,
+                        createVariableDeclarationList(hoistedVariableDeclarations)
+                    );
+
+                    if (!statements) {
+                        statements = [statement];
+                    }
+                    else {
+                        statements.push(statement);
+                    }
+                }
+            }
+
+            // Restore the previous lexical environment.
+            lexicalEnvironmentStackOffset--;
+            hoistedVariableDeclarations = lexicalEnvironmentVariableDeclarationsStack[lexicalEnvironmentStackOffset];
+            hoistedFunctionDeclarations = lexicalEnvironmentFunctionDeclarationsStack[lexicalEnvironmentStackOffset];
+            return statements;
+        }
+    }
+}

src/compiler/transformers/destructuring.ts

@@ -0,0 +1,445 @@
+/// <reference path="../factory.ts" />
+/// <reference path="../visitor.ts" />
+
+/*@internal*/
+namespace ts {
+    /**
+     * Flattens a destructuring assignment expression.
+     *
+     * @param root The destructuring assignment expression.
+     * @param needsValue Indicates whether the value from the right-hand-side of the
+     *                   destructuring assignment is needed as part of a larger expression.
+     * @param recordTempVariable A callback used to record new temporary variables.
+     * @param visitor An optional visitor to use to visit expressions.
+     */
+    export function flattenDestructuringAssignment(
+        context: TransformationContext,
+        node: BinaryExpression,
+        needsValue: boolean,
+        recordTempVariable: (node: Identifier) => void,
+        visitor?: (node: Node) => VisitResult<Node>): Expression {
+
+        if (isEmptyObjectLiteralOrArrayLiteral(node.left)) {
+            const right = node.right;
+            if (isDestructuringAssignment(right)) {
+                return flattenDestructuringAssignment(context, right, needsValue, recordTempVariable, visitor);
+            }
+            else {
+                return node.right;
+            }
+        }
+
+        let location: TextRange = node;
+        let value = node.right;
+        const expressions: Expression[] = [];
+        if (needsValue) {
+            // If the right-hand value of the destructuring assignment needs to be preserved (as
+            // is the case when the destructuring assignmen) is part of a larger expression),
+            // then we need to cache the right-hand value.
+            //
+            // The source map location for the assignment should point to the entire binary
+            // expression.
+            value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ true, location, emitTempVariableAssignment, visitor);
+        }
+        else if (nodeIsSynthesized(node)) {
+            // Generally, the source map location for a destructuring assignment is the root
+            // expression.
+            //
+            // However, if the root expression is synthesized (as in the case
+            // of the initializer when transforming a ForOfStatement), then the source map
+            // location should point to the right-hand value of the expression.
+            location = value;
+        }
+
+        flattenDestructuring(context, node, value, location, emitAssignment, emitTempVariableAssignment, visitor);
+
+        if (needsValue) {
+            expressions.push(value);
+        }
+
+        const expression = inlineExpressions(expressions);
+        aggregateTransformFlags(expression);
+        return expression;
+
+        function emitAssignment(name: Identifier, value: Expression, location: TextRange) {
+            const expression = createAssignment(name, value, location);
+
+            // NOTE: this completely disables source maps, but aligns with the behavior of
+            //       `emitAssignment` in the old emitter.
+            setEmitFlags(expression, EmitFlags.NoNestedSourceMaps);
+
+            aggregateTransformFlags(expression);
+            expressions.push(expression);
+        }
+
+        function emitTempVariableAssignment(value: Expression, location: TextRange) {
+            const name = createTempVariable(recordTempVariable);
+            emitAssignment(name, value, location);
+            return name;
+        }
+    }
+
+    /**
+     * Flattens binding patterns in a parameter declaration.
+     *
+     * @param node The ParameterDeclaration to flatten.
+     * @param value The rhs value for the binding pattern.
+     * @param visitor An optional visitor to use to visit expressions.
+     */
+    export function flattenParameterDestructuring(
+        context: TransformationContext,
+        node: ParameterDeclaration,
+        value: Expression,
+        visitor?: (node: Node) => VisitResult<Node>) {
+        const declarations: VariableDeclaration[] = [];
+
+        flattenDestructuring(context, node, value, node, emitAssignment, emitTempVariableAssignment, visitor);
+
+        return declarations;
+
+        function emitAssignment(name: Identifier, value: Expression, location: TextRange) {
+            const declaration = createVariableDeclaration(name, /*type*/ undefined, value, location);
+
+            // NOTE: this completely disables source maps, but aligns with the behavior of
+            //       `emitAssignment` in the old emitter.
+            setEmitFlags(declaration, EmitFlags.NoNestedSourceMaps);
+
+            aggregateTransformFlags(declaration);
+            declarations.push(declaration);
+        }
+
+        function emitTempVariableAssignment(value: Expression, location: TextRange) {
+            const name = createTempVariable(/*recordTempVariable*/ undefined);
+            emitAssignment(name, value, location);
+            return name;
+        }
+    }
+
+    /**
+     * Flattens binding patterns in a variable declaration.
+     *
+     * @param node The VariableDeclaration to flatten.
+     * @param value An optional rhs value for the binding pattern.
+     * @param visitor An optional visitor to use to visit expressions.
+     */
+    export function flattenVariableDestructuring(
+        context: TransformationContext,
+        node: VariableDeclaration,
+        value?: Expression,
+        visitor?: (node: Node) => VisitResult<Node>,
+        recordTempVariable?: (node: Identifier) => void) {
+        const declarations: VariableDeclaration[] = [];
+
+        let pendingAssignments: Expression[];
+        flattenDestructuring(context, node, value, node, emitAssignment, emitTempVariableAssignment, visitor);
+
+        return declarations;
+
+        function emitAssignment(name: Identifier, value: Expression, location: TextRange, original: Node) {
+            if (pendingAssignments) {
+                pendingAssignments.push(value);
+                value = inlineExpressions(pendingAssignments);
+                pendingAssignments = undefined;
+            }
+
+            const declaration = createVariableDeclaration(name, /*type*/ undefined, value, location);
+            declaration.original = original;
+
+            // NOTE: this completely disables source maps, but aligns with the behavior of
+            //       `emitAssignment` in the old emitter.
+            setEmitFlags(declaration, EmitFlags.NoNestedSourceMaps);
+
+            declarations.push(declaration);
+            aggregateTransformFlags(declaration);
+        }
+
+        function emitTempVariableAssignment(value: Expression, location: TextRange) {
+            const name = createTempVariable(recordTempVariable);
+            if (recordTempVariable) {
+                const assignment = createAssignment(name, value, location);
+                if (pendingAssignments) {
+                    pendingAssignments.push(assignment);
+                }
+                else {
+                    pendingAssignments = [assignment];
+                }
+            }
+            else {
+                emitAssignment(name, value, location, /*original*/ undefined);
+            }
+            return name;
+        }
+    }
+
+    /**
+     * Flattens binding patterns in a variable declaration and transforms them into an expression.
+     *
+     * @param node The VariableDeclaration to flatten.
+     * @param recordTempVariable A callback used to record new temporary variables.
+     * @param nameSubstitution An optional callback used to substitute binding names.
+     * @param visitor An optional visitor to use to visit expressions.
+     */
+    export function flattenVariableDestructuringToExpression(
+        context: TransformationContext,
+        node: VariableDeclaration,
+        recordTempVariable: (name: Identifier) => void,
+        nameSubstitution?: (name: Identifier) => Expression,
+        visitor?: (node: Node) => VisitResult<Node>) {
+
+        const pendingAssignments: Expression[] = [];
+
+        flattenDestructuring(context, node, /*value*/ undefined, node, emitAssignment, emitTempVariableAssignment, visitor);
+
+        const expression = inlineExpressions(pendingAssignments);
+        aggregateTransformFlags(expression);
+        return expression;
+
+        function emitAssignment(name: Identifier, value: Expression, location: TextRange, original: Node) {
+            const left = nameSubstitution && nameSubstitution(name) || name;
+            emitPendingAssignment(left, value, location, original);
+        }
+
+        function emitTempVariableAssignment(value: Expression, location: TextRange) {
+            const name = createTempVariable(recordTempVariable);
+            emitPendingAssignment(name, value, location, /*original*/ undefined);
+            return name;
+        }
+
+        function emitPendingAssignment(name: Expression, value: Expression, location: TextRange, original: Node) {
+            const expression = createAssignment(name, value, location);
+            expression.original = original;
+
+            // NOTE: this completely disables source maps, but aligns with the behavior of
+            //       `emitAssignment` in the old emitter.
+            setEmitFlags(expression, EmitFlags.NoNestedSourceMaps);
+
+            pendingAssignments.push(expression);
+            return expression;
+        }
+    }
+
+    function flattenDestructuring(
+        context: TransformationContext,
+        root: BindingElement | BinaryExpression,
+        value: Expression,
+        location: TextRange,
+        emitAssignment: (name: Identifier, value: Expression, location: TextRange, original: Node) => void,
+        emitTempVariableAssignment: (value: Expression, location: TextRange) => Identifier,
+        visitor?: (node: Node) => VisitResult<Node>) {
+        if (value && visitor) {
+            value = visitNode(value, visitor, isExpression);
+        }
+
+        if (isBinaryExpression(root)) {
+            emitDestructuringAssignment(root.left, value, location);
+        }
+        else {
+            emitBindingElement(root, value);
+        }
+
+        function emitDestructuringAssignment(bindingTarget: Expression | ShorthandPropertyAssignment, value: Expression, location: TextRange) {
+            // When emitting target = value use source map node to highlight, including any temporary assignments needed for this
+            let target: Expression;
+            if (isShorthandPropertyAssignment(bindingTarget)) {
+                const initializer = visitor
+                    ? visitNode(bindingTarget.objectAssignmentInitializer, visitor, isExpression)
+                    : bindingTarget.objectAssignmentInitializer;
+
+                if (initializer) {
+                    value = createDefaultValueCheck(value, initializer, location);
+                }
+
+                target = bindingTarget.name;
+            }
+            else if (isBinaryExpression(bindingTarget) && bindingTarget.operatorToken.kind === SyntaxKind.EqualsToken) {
+                const initializer = visitor
+                    ? visitNode(bindingTarget.right, visitor, isExpression)
+                    : bindingTarget.right;
+
+                value = createDefaultValueCheck(value, initializer, location);
+                target = bindingTarget.left;
+            }
+            else {
+                target = bindingTarget;
+            }
+
+            if (target.kind === SyntaxKind.ObjectLiteralExpression) {
+                emitObjectLiteralAssignment(<ObjectLiteralExpression>target, value, location);
+            }
+            else if (target.kind === SyntaxKind.ArrayLiteralExpression) {
+                emitArrayLiteralAssignment(<ArrayLiteralExpression>target, value, location);
+            }
+            else {
+                const name = getMutableClone(<Identifier>target);
+                setSourceMapRange(name, target);
+                setCommentRange(name, target);
+                emitAssignment(name, value, location, /*original*/ undefined);
+            }
+        }
+
+        function emitObjectLiteralAssignment(target: ObjectLiteralExpression, value: Expression, location: TextRange) {
+            const properties = target.properties;
+            if (properties.length !== 1) {
+                // For anything but a single element destructuring we need to generate a temporary
+                // to ensure value is evaluated exactly once.
+                // When doing so we want to hightlight the passed in source map node since thats the one needing this temp assignment
+                value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ true, location, emitTempVariableAssignment);
+            }
+
+            for (const p of properties) {
+                if (p.kind === SyntaxKind.PropertyAssignment || p.kind === SyntaxKind.ShorthandPropertyAssignment) {
+                    const propName = <Identifier | LiteralExpression>(<PropertyAssignment>p).name;
+                    const target = p.kind === SyntaxKind.ShorthandPropertyAssignment ? <ShorthandPropertyAssignment>p : (<PropertyAssignment>p).initializer || propName;
+                    // Assignment for target = value.propName should highligh whole property, hence use p as source map node
+                    emitDestructuringAssignment(target, createDestructuringPropertyAccess(value, propName), p);
+                }
+            }
+        }
+
+        function emitArrayLiteralAssignment(target: ArrayLiteralExpression, value: Expression, location: TextRange) {
+            const elements = target.elements;
+            const numElements = elements.length;
+            if (numElements !== 1) {
+                // For anything but a single element destructuring we need to generate a temporary
+                // to ensure value is evaluated exactly once.
+                // When doing so we want to hightlight the passed in source map node since thats the one needing this temp assignment
+                value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ true, location, emitTempVariableAssignment);
+            }
+
+            for (let i = 0; i < numElements; i++) {
+                const e = elements[i];
+                if (e.kind !== SyntaxKind.OmittedExpression) {
+                    // Assignment for target = value.propName should highligh whole property, hence use e as source map node
+                    if (e.kind !== SyntaxKind.SpreadElementExpression) {
+                        emitDestructuringAssignment(e, createElementAccess(value, createLiteral(i)), e);
+                    }
+                    else if (i === numElements - 1) {
+                        emitDestructuringAssignment((<SpreadElementExpression>e).expression, createArraySlice(value, i), e);
+                    }
+                }
+            }
+        }
+
+        function emitBindingElement(target: BindingElement, value: Expression) {
+            // Any temporary assignments needed to emit target = value should point to target
+            const initializer = visitor ? visitNode(target.initializer, visitor, isExpression) : target.initializer;
+            if (initializer) {
+                // Combine value and initializer
+                value = value ? createDefaultValueCheck(value, initializer, target) : initializer;
+            }
+            else if (!value) {
+                // Use 'void 0' in absence of value and initializer
+                value = createVoidZero();
+            }
+
+            const name = target.name;
+            if (isBindingPattern(name)) {
+                const elements = name.elements;
+                const numElements = elements.length;
+                if (numElements !== 1) {
+                    // For anything other than a single-element destructuring we need to generate a temporary
+                    // to ensure value is evaluated exactly once. Additionally, if we have zero elements
+                    // we need to emit *something* to ensure that in case a 'var' keyword was already emitted,
+                    // so in that case, we'll intentionally create that temporary.
+                    value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ numElements !== 0, target, emitTempVariableAssignment);
+                }
+                for (let i = 0; i < numElements; i++) {
+                    const element = elements[i];
+                    if (isOmittedExpression(element)) {
+                        continue;
+                    }
+                    else if (name.kind === SyntaxKind.ObjectBindingPattern) {
+                        // Rewrite element to a declaration with an initializer that fetches property
+                        const propName = element.propertyName || <Identifier>element.name;
+                        emitBindingElement(element, createDestructuringPropertyAccess(value, propName));
+                    }
+                    else {
+                        if (!element.dotDotDotToken) {
+                            // Rewrite element to a declaration that accesses array element at index i
+                            emitBindingElement(element, createElementAccess(value, i));
+                        }
+                        else if (i === numElements - 1) {
+                            emitBindingElement(element, createArraySlice(value, i));
+                        }
+                    }
+                }
+            }
+            else {
+                emitAssignment(name, value, target, target);
+            }
+        }
+
+        function createDefaultValueCheck(value: Expression, defaultValue: Expression, location: TextRange): Expression {
+            value = ensureIdentifier(value, /*reuseIdentifierExpressions*/ true, location, emitTempVariableAssignment);
+            return createConditional(
+                createStrictEquality(value, createVoidZero()),
+                createToken(SyntaxKind.QuestionToken),
+                defaultValue,
+                createToken(SyntaxKind.ColonToken),
+                value
+            );
+        }
+
+        /**
+         * Creates either a PropertyAccessExpression or an ElementAccessExpression for the
+         * right-hand side of a transformed destructuring assignment.
+         *
+         * @param expression The right-hand expression that is the source of the property.
+         * @param propertyName The destructuring property name.
+         */
+        function createDestructuringPropertyAccess(expression: Expression, propertyName: PropertyName): LeftHandSideExpression {
+            if (isComputedPropertyName(propertyName)) {
+                return createElementAccess(
+                    expression,
+                    ensureIdentifier(propertyName.expression, /*reuseIdentifierExpressions*/ false, /*location*/ propertyName, emitTempVariableAssignment)
+                );
+            }
+            else if (isLiteralExpression(propertyName)) {
+                const clone = getSynthesizedClone(propertyName);
+                clone.text = unescapeIdentifier(clone.text);
+                return createElementAccess(expression, clone);
+            }
+            else {
+                if (isGeneratedIdentifier(propertyName)) {
+                    const clone = getSynthesizedClone(propertyName);
+                    clone.text = unescapeIdentifier(clone.text);
+                    return createPropertyAccess(expression, clone);
+                }
+                else {
+                    return createPropertyAccess(expression, createIdentifier(unescapeIdentifier(propertyName.text)));
+                }
+            }
+        }
+    }
+
+    /**
+     * Ensures that there exists a declared identifier whose value holds the given expression.
+     * This function is useful to ensure that the expression's value can be read from in subsequent expressions.
+     * Unless 'reuseIdentifierExpressions' is false, 'value' will be returned if it is just an identifier.
+     *
+     * @param value the expression whose value needs to be bound.
+     * @param reuseIdentifierExpressions true if identifier expressions can simply be returned;
+     *                                   false if it is necessary to always emit an identifier.
+     * @param location The location to use for source maps and comments.
+     * @param emitTempVariableAssignment A callback used to emit a temporary variable.
+     * @param visitor An optional callback used to visit the value.
+     */
+    function ensureIdentifier(
+        value: Expression,
+        reuseIdentifierExpressions: boolean,
+        location: TextRange,
+        emitTempVariableAssignment: (value: Expression, location: TextRange) => Identifier,
+        visitor?: (node: Node) => VisitResult<Node>) {
+
+        if (isIdentifier(value) && reuseIdentifierExpressions) {
+            return value;
+        }
+        else {
+            if (visitor) {
+                value = visitNode(value, visitor, isExpression);
+            }
+
+            return emitTempVariableAssignment(value, location);
+        }
+    }
+}

src/compiler/transformers/es7.ts

@@ -0,0 +1,101 @@
+/// <reference path="../factory.ts" />
+/// <reference path="../visitor.ts" />
+
+/*@internal*/
+namespace ts {
+    export function transformES7(context: TransformationContext) {
+        const { hoistVariableDeclaration } = context;
+
+        return transformSourceFile;
+
+        function transformSourceFile(node: SourceFile) {
+            if (isDeclarationFile(node)) {
+                return node;
+            }
+
+            return visitEachChild(node, visitor, context);
+        }
+
+        function visitor(node: Node): VisitResult<Node> {
+            if (node.transformFlags & TransformFlags.ES7) {
+                return visitorWorker(node);
+            }
+            else if (node.transformFlags & TransformFlags.ContainsES7) {
+                return visitEachChild(node, visitor, context);
+            }
+            else {
+                return node;
+            }
+        }
+
+        function visitorWorker(node: Node): VisitResult<Node> {
+            switch (node.kind) {
+                case SyntaxKind.BinaryExpression:
+                    return visitBinaryExpression(<BinaryExpression>node);
+
+                default:
+                    Debug.failBadSyntaxKind(node);
+                    return visitEachChild(node, visitor, context);
+            }
+        }
+
+        function visitBinaryExpression(node: BinaryExpression): Expression {
+            // We are here because ES7 adds support for the exponentiation operator.
+            const left = visitNode(node.left, visitor, isExpression);
+            const right = visitNode(node.right, visitor, isExpression);
+            if (node.operatorToken.kind === SyntaxKind.AsteriskAsteriskEqualsToken) {
+                let target: Expression;
+                let value: Expression;
+                if (isElementAccessExpression(left)) {
+                    // Transforms `a[x] **= b` into `(_a = a)[_x = x] = Math.pow(_a[_x], b)`
+                    const expressionTemp = createTempVariable(hoistVariableDeclaration);
+
+                    const argumentExpressionTemp = createTempVariable(hoistVariableDeclaration);
+
+                    target = createElementAccess(
+                        createAssignment(expressionTemp, left.expression, /*location*/ left.expression),
+                        createAssignment(argumentExpressionTemp, left.argumentExpression, /*location*/ left.argumentExpression),
+                        /*location*/ left
+                    );
+
+                    value = createElementAccess(
+                        expressionTemp,
+                        argumentExpressionTemp,
+                        /*location*/ left
+                    );
+                }
+                else if (isPropertyAccessExpression(left)) {
+                    // Transforms `a.x **= b` into `(_a = a).x = Math.pow(_a.x, b)`
+                    const expressionTemp = createTempVariable(hoistVariableDeclaration);
+
+                    target = createPropertyAccess(
+                        createAssignment(expressionTemp, left.expression, /*location*/ left.expression),
+                        left.name,
+                        /*location*/ left
+                    );
+
+                    value = createPropertyAccess(
+                        expressionTemp,
+                        left.name,
+                        /*location*/ left
+                    );
+                }
+                else {
+                    // Transforms `a **= b` into `a = Math.pow(a, b)`
+                    target = left;
+                    value = left;
+                }
+
+                return createAssignment(target, createMathPow(value, right, /*location*/ node), /*location*/ node);
+            }
+            else if (node.operatorToken.kind === SyntaxKind.AsteriskAsteriskToken) {
+                // Transforms `a ** b` into `Math.pow(a, b)`
+                return createMathPow(left, right, /*location*/ node);
+            }
+            else {
+                Debug.failBadSyntaxKind(node);
+                return visitEachChild(node, visitor, context);
+            }
+        }
+    }
+}

src/compiler/transformers/jsx.ts

@@ -0,0 +1,535 @@
+/// <reference path="../factory.ts" />
+/// <reference path="../visitor.ts" />
+
+/*@internal*/
+namespace ts {
+    const entities: Map<number> = createEntitiesMap();
+
+    export function transformJsx(context: TransformationContext) {
+        const compilerOptions = context.getCompilerOptions();
+        let currentSourceFile: SourceFile;
+        return transformSourceFile;
+
+        /**
+         * Transform JSX-specific syntax in a SourceFile.
+         *
+         * @param node A SourceFile node.
+         */
+        function transformSourceFile(node: SourceFile) {
+            if (isDeclarationFile(node)) {
+                return node;
+            }
+
+            currentSourceFile = node;
+            node = visitEachChild(node, visitor, context);
+            currentSourceFile = undefined;
+            return node;
+        }
+
+        function visitor(node: Node): VisitResult<Node> {
+            if (node.transformFlags & TransformFlags.Jsx) {
+                return visitorWorker(node);
+            }
+            else if (node.transformFlags & TransformFlags.ContainsJsx) {
+                return visitEachChild(node, visitor, context);
+            }
+            else {
+                return node;
+            }
+        }
+
+        function visitorWorker(node: Node): VisitResult<Node> {
+            switch (node.kind) {
+                case SyntaxKind.JsxElement:
+                    return visitJsxElement(<JsxElement>node, /*isChild*/ false);
+
+                case SyntaxKind.JsxSelfClosingElement:
+                    return visitJsxSelfClosingElement(<JsxSelfClosingElement>node, /*isChild*/ false);
+
+                case SyntaxKind.JsxExpression:
+                    return visitJsxExpression(<JsxExpression>node);
+
+                default:
+                    Debug.failBadSyntaxKind(node);
+                    return undefined;
+            }
+        }
+
+        function transformJsxChildToExpression(node: JsxChild): Expression {
+            switch (node.kind) {
+                case SyntaxKind.JsxText:
+                    return visitJsxText(<JsxText>node);
+
+                case SyntaxKind.JsxExpression:
+                    return visitJsxExpression(<JsxExpression>node);
+
+                case SyntaxKind.JsxElement:
+                    return visitJsxElement(<JsxElement>node, /*isChild*/ true);
+
+                case SyntaxKind.JsxSelfClosingElement:
+                    return visitJsxSelfClosingElement(<JsxSelfClosingElement>node, /*isChild*/ true);
+
+                default:
+                    Debug.failBadSyntaxKind(node);
+                    return undefined;
+            }
+        }
+
+        function visitJsxElement(node: JsxElement, isChild: boolean) {
+            return visitJsxOpeningLikeElement(node.openingElement, node.children, isChild, /*location*/ node);
+        }
+
+        function visitJsxSelfClosingElement(node: JsxSelfClosingElement, isChild: boolean) {
+            return visitJsxOpeningLikeElement(node, /*children*/ undefined, isChild, /*location*/ node);
+        }
+
+        function visitJsxOpeningLikeElement(node: JsxOpeningLikeElement, children: JsxChild[], isChild: boolean, location: TextRange) {
+            const tagName = getTagName(node);
+            let objectProperties: Expression;
+            const attrs = node.attributes;
+            if (attrs.length === 0) {
+                // When there are no attributes, React wants "null"
+                objectProperties = createNull();
+            }
+            else {
+                // Map spans of JsxAttribute nodes into object literals and spans
+                // of JsxSpreadAttribute nodes into expressions.
+                const segments = flatten(
+                    spanMap(attrs, isJsxSpreadAttribute, (attrs, isSpread) => isSpread
+                        ? map(attrs, transformJsxSpreadAttributeToExpression)
+                        : createObjectLiteral(map(attrs, transformJsxAttributeToObjectLiteralElement))
+                    )
+                );
+
+                if (isJsxSpreadAttribute(attrs[0])) {
+                    // We must always emit at least one object literal before a spread
+                    // argument.
+                    segments.unshift(createObjectLiteral());
+                }
+
+                // Either emit one big object literal (no spread attribs), or
+                // a call to the __assign helper.
+                objectProperties = singleOrUndefined(segments)
+                    || createAssignHelper(currentSourceFile.externalHelpersModuleName, segments);
+            }
+
+            const element = createReactCreateElement(
+                compilerOptions.reactNamespace,
+                tagName,
+                objectProperties,
+                filter(map(children, transformJsxChildToExpression), isDefined),
+                node,
+                location
+            );
+
+            if (isChild) {
+                startOnNewLine(element);
+            }
+
+            return element;
+        }
+
+        function transformJsxSpreadAttributeToExpression(node: JsxSpreadAttribute) {
+            return visitNode(node.expression, visitor, isExpression);
+        }
+
+        function transformJsxAttributeToObjectLiteralElement(node: JsxAttribute) {
+            const name = getAttributeName(node);
+            const expression = transformJsxAttributeInitializer(node.initializer);
+            return createPropertyAssignment(name, expression);
+        }
+
+        function transformJsxAttributeInitializer(node: StringLiteral | JsxExpression) {
+            if (node === undefined) {
+                return createLiteral(true);
+            }
+            else if (node.kind === SyntaxKind.StringLiteral) {
+                const decoded = tryDecodeEntities((<StringLiteral>node).text);
+                return decoded ? createLiteral(decoded, /*location*/ node) : node;
+            }
+            else if (node.kind === SyntaxKind.JsxExpression) {
+                return visitJsxExpression(<JsxExpression>node);
+            }
+            else {
+                Debug.failBadSyntaxKind(node);
+            }
+        }
+
+        function visitJsxText(node: JsxText) {
+            const text = getTextOfNode(node, /*includeTrivia*/ true);
+            let parts: Expression[];
+            let firstNonWhitespace = 0;
+            let lastNonWhitespace = -1;
+
+            // JSX trims whitespace at the end and beginning of lines, except that the
+            // start/end of a tag is considered a start/end of a line only if that line is
+            // on the same line as the closing tag. See examples in
+            // tests/cases/conformance/jsx/tsxReactEmitWhitespace.tsx
+            for (let i = 0; i < text.length; i++) {
+                const c = text.charCodeAt(i);
+                if (isLineBreak(c)) {
+                    if (firstNonWhitespace !== -1 && (lastNonWhitespace - firstNonWhitespace + 1 > 0)) {
+                        const part = text.substr(firstNonWhitespace, lastNonWhitespace - firstNonWhitespace + 1);
+                        if (!parts) {
+                            parts = [];
+                        }
+
+                        // We do not escape the string here as that is handled by the printer
+                        // when it emits the literal. We do, however, need to decode JSX entities.
+                        parts.push(createLiteral(decodeEntities(part)));
+                    }
+
+                    firstNonWhitespace = -1;
+                }
+                else if (!isWhiteSpace(c)) {
+                    lastNonWhitespace = i;
+                    if (firstNonWhitespace === -1) {
+                        firstNonWhitespace = i;
+                    }
+                }
+            }
+
+            if (firstNonWhitespace !== -1) {
+                const part = text.substr(firstNonWhitespace);
+                if (!parts) {
+                    parts = [];
+                }
+
+                // We do not escape the string here as that is handled by the printer
+                // when it emits the literal. We do, however, need to decode JSX entities.
+                parts.push(createLiteral(decodeEntities(part)));
+            }
+
+            if (parts) {
+                return reduceLeft(parts, aggregateJsxTextParts);
+            }
+
+            return undefined;
+        }
+
+        /**
+         * Aggregates two expressions by interpolating them with a whitespace literal.
+         */
+        function aggregateJsxTextParts(left: Expression, right: Expression) {
+            return createAdd(createAdd(left, createLiteral(" ")), right);
+        }
+
+        /**
+         * Replace entities like "&nbsp;", "&#123;", and "&#xDEADBEEF;" with the characters they encode.
+         * See https://en.wikipedia.org/wiki/List_of_XML_and_HTML_character_entity_references
+         */
+        function decodeEntities(text: string): string {
+            return text.replace(/&((#((\d+)|x([\da-fA-F]+)))|(\w+));/g, (match, _all, _number, _digits, decimal, hex, word) => {
+                if (decimal) {
+                    return String.fromCharCode(parseInt(decimal, 10));
+                }
+                else if (hex) {
+                    return String.fromCharCode(parseInt(hex, 16));
+                }
+                else {
+                    const ch = entities[word];
+                    // If this is not a valid entity, then just use `match` (replace it with itself, i.e. don't replace)
+                    return ch ? String.fromCharCode(ch) : match;
+                }
+            });
+        }
+
+        /** Like `decodeEntities` but returns `undefined` if there were no entities to decode. */
+        function tryDecodeEntities(text: string): string | undefined {
+            const decoded = decodeEntities(text);
+            return decoded === text ? undefined : decoded;
+        }
+
+        function getTagName(node: JsxElement | JsxOpeningLikeElement): Expression {
+            if (node.kind === SyntaxKind.JsxElement) {
+                return getTagName((<JsxElement>node).openingElement);
+            }
+            else {
+                const name = (<JsxOpeningLikeElement>node).tagName;
+                if (isIdentifier(name) && isIntrinsicJsxName(name.text)) {
+                    return createLiteral(name.text);
+                }
+                else {
+                    return createExpressionFromEntityName(name);
+                }
+            }
+        }
+
+        /**
+         * Emit an attribute name, which is quoted if it needs to be quoted. Because
+         * these emit into an object literal property name, we don't need to be worried
+         * about keywords, just non-identifier characters
+         */
+        function getAttributeName(node: JsxAttribute): StringLiteral | Identifier {
+            const name = node.name;
+            if (/^[A-Za-z_]\w*$/.test(name.text)) {
+                return name;
+            }
+            else {
+                return createLiteral(name.text);
+            }
+        }
+
+        function visitJsxExpression(node: JsxExpression) {
+            return visitNode(node.expression, visitor, isExpression);
+        }
+    }
+
+    function createEntitiesMap(): Map<number> {
+        return createMap<number>({
+            "quot": 0x0022,
+            "amp": 0x0026,
+            "apos": 0x0027,
+            "lt": 0x003C,
+            "gt": 0x003E,
+            "nbsp": 0x00A0,
+            "iexcl": 0x00A1,
+            "cent": 0x00A2,
+            "pound": 0x00A3,
+            "curren": 0x00A4,
+            "yen": 0x00A5,
+            "brvbar": 0x00A6,
+            "sect": 0x00A7,
+            "uml": 0x00A8,
+            "copy": 0x00A9,
+            "ordf": 0x00AA,
+            "laquo": 0x00AB,
+            "not": 0x00AC,
+            "shy": 0x00AD,
+            "reg": 0x00AE,
+            "macr": 0x00AF,
+            "deg": 0x00B0,
+            "plusmn": 0x00B1,
+            "sup2": 0x00B2,
+            "sup3": 0x00B3,
+            "acute": 0x00B4,
+            "micro": 0x00B5,
+            "para": 0x00B6,
+            "middot": 0x00B7,
+            "cedil": 0x00B8,
+            "sup1": 0x00B9,
+            "ordm": 0x00BA,
+            "raquo": 0x00BB,
+            "frac14": 0x00BC,
+            "frac12": 0x00BD,
+            "frac34": 0x00BE,
+            "iquest": 0x00BF,
+            "Agrave": 0x00C0,
+            "Aacute": 0x00C1,
+            "Acirc": 0x00C2,
+            "Atilde": 0x00C3,
+            "Auml": 0x00C4,
+            "Aring": 0x00C5,
+            "AElig": 0x00C6,
+            "Ccedil": 0x00C7,
+            "Egrave": 0x00C8,
+            "Eacute": 0x00C9,
+            "Ecirc": 0x00CA,
+            "Euml": 0x00CB,
+            "Igrave": 0x00CC,
+            "Iacute": 0x00CD,
+            "Icirc": 0x00CE,
+            "Iuml": 0x00CF,
+            "ETH": 0x00D0,
+            "Ntilde": 0x00D1,
+            "Ograve": 0x00D2,
+            "Oacute": 0x00D3,
+            "Ocirc": 0x00D4,
+            "Otilde": 0x00D5,
+            "Ouml": 0x00D6,
+            "times": 0x00D7,
+            "Oslash": 0x00D8,
+            "Ugrave": 0x00D9,
+            "Uacute": 0x00DA,
+            "Ucirc": 0x00DB,
+            "Uuml": 0x00DC,
+            "Yacute": 0x00DD,
+            "THORN": 0x00DE,
+            "szlig": 0x00DF,
+            "agrave": 0x00E0,
+            "aacute": 0x00E1,
+            "acirc": 0x00E2,
+            "atilde": 0x00E3,
+            "auml": 0x00E4,
+            "aring": 0x00E5,
+            "aelig": 0x00E6,
+            "ccedil": 0x00E7,
+            "egrave": 0x00E8,
+            "eacute": 0x00E9,
+            "ecirc": 0x00EA,
+            "euml": 0x00EB,
+            "igrave": 0x00EC,
+            "iacute": 0x00ED,
+            "icirc": 0x00EE,
+            "iuml": 0x00EF,
+            "eth": 0x00F0,
+            "ntilde": 0x00F1,
+            "ograve": 0x00F2,
+            "oacute": 0x00F3,
+            "ocirc": 0x00F4,
+            "otilde": 0x00F5,
+            "ouml": 0x00F6,
+            "divide": 0x00F7,
+            "oslash": 0x00F8,
+            "ugrave": 0x00F9,
+            "uacute": 0x00FA,
+            "ucirc": 0x00FB,
+            "uuml": 0x00FC,
+            "yacute": 0x00FD,
+            "thorn": 0x00FE,
+            "yuml": 0x00FF,
+            "OElig": 0x0152,
+            "oelig": 0x0153,
+            "Scaron": 0x0160,
+            "scaron": 0x0161,
+            "Yuml": 0x0178,
+            "fnof": 0x0192,
+            "circ": 0x02C6,
+            "tilde": 0x02DC,
+            "Alpha": 0x0391,
+            "Beta": 0x0392,
+            "Gamma": 0x0393,
+            "Delta": 0x0394,
+            "Epsilon": 0x0395,
+            "Zeta": 0x0396,
+            "Eta": 0x0397,
+            "Theta": 0x0398,
+            "Iota": 0x0399,
+            "Kappa": 0x039A,
+            "Lambda": 0x039B,
+            "Mu": 0x039C,
+            "Nu": 0x039D,
+            "Xi": 0x039E,
+            "Omicron": 0x039F,
+            "Pi": 0x03A0,
+            "Rho": 0x03A1,
+            "Sigma": 0x03A3,
+            "Tau": 0x03A4,
+            "Upsilon": 0x03A5,
+            "Phi": 0x03A6,
+            "Chi": 0x03A7,
+            "Psi": 0x03A8,
+            "Omega": 0x03A9,
+            "alpha": 0x03B1,
+            "beta": 0x03B2,
+            "gamma": 0x03B3,
+            "delta": 0x03B4,
+            "epsilon": 0x03B5,
+            "zeta": 0x03B6,
+            "eta": 0x03B7,
+            "theta": 0x03B8,
+            "iota": 0x03B9,
+            "kappa": 0x03BA,
+            "lambda": 0x03BB,
+            "mu": 0x03BC,
+            "nu": 0x03BD,
+            "xi": 0x03BE,
+            "omicron": 0x03BF,
+            "pi": 0x03C0,
+            "rho": 0x03C1,
+            "sigmaf": 0x03C2,
+            "sigma": 0x03C3,
+            "tau": 0x03C4,
+            "upsilon": 0x03C5,
+            "phi": 0x03C6,
+            "chi": 0x03C7,
+            "psi": 0x03C8,
+            "omega": 0x03C9,
+            "thetasym": 0x03D1,
+            "upsih": 0x03D2,
+            "piv": 0x03D6,
+            "ensp": 0x2002,
+            "emsp": 0x2003,
+            "thinsp": 0x2009,
+            "zwnj": 0x200C,
+            "zwj": 0x200D,
+            "lrm": 0x200E,
+            "rlm": 0x200F,
+            "ndash": 0x2013,
+            "mdash": 0x2014,
+            "lsquo": 0x2018,
+            "rsquo": 0x2019,
+            "sbquo": 0x201A,
+            "ldquo": 0x201C,
+            "rdquo": 0x201D,
+            "bdquo": 0x201E,
+            "dagger": 0x2020,
+            "Dagger": 0x2021,
+            "bull": 0x2022,
+            "hellip": 0x2026,
+            "permil": 0x2030,
+            "prime": 0x2032,
+            "Prime": 0x2033,
+            "lsaquo": 0x2039,
+            "rsaquo": 0x203A,
+            "oline": 0x203E,
+            "frasl": 0x2044,
+            "euro": 0x20AC,
+            "image": 0x2111,
+            "weierp": 0x2118,
+            "real": 0x211C,
+            "trade": 0x2122,
+            "alefsym": 0x2135,
+            "larr": 0x2190,
+            "uarr": 0x2191,
+            "rarr": 0x2192,
+            "darr": 0x2193,
+            "harr": 0x2194,
+            "crarr": 0x21B5,
+            "lArr": 0x21D0,
+            "uArr": 0x21D1,
+            "rArr": 0x21D2,
+            "dArr": 0x21D3,
+            "hArr": 0x21D4,
+            "forall": 0x2200,
+            "part": 0x2202,
+            "exist": 0x2203,
+            "empty": 0x2205,
+            "nabla": 0x2207,
+            "isin": 0x2208,
+            "notin": 0x2209,
+            "ni": 0x220B,
+            "prod": 0x220F,
+            "sum": 0x2211,
+            "minus": 0x2212,
+            "lowast": 0x2217,
+            "radic": 0x221A,
+            "prop": 0x221D,
+            "infin": 0x221E,
+            "ang": 0x2220,
+            "and": 0x2227,
+            "or": 0x2228,
+            "cap": 0x2229,
+            "cup": 0x222A,
+            "int": 0x222B,
+            "there4": 0x2234,
+            "sim": 0x223C,
+            "cong": 0x2245,
+            "asymp": 0x2248,
+            "ne": 0x2260,
+            "equiv": 0x2261,
+            "le": 0x2264,
+            "ge": 0x2265,
+            "sub": 0x2282,
+            "sup": 0x2283,
+            "nsub": 0x2284,
+            "sube": 0x2286,
+            "supe": 0x2287,
+            "oplus": 0x2295,
+            "otimes": 0x2297,
+            "perp": 0x22A5,
+            "sdot": 0x22C5,
+            "lceil": 0x2308,
+            "rceil": 0x2309,
+            "lfloor": 0x230A,
+            "rfloor": 0x230B,
+            "lang": 0x2329,
+            "rang": 0x232A,
+            "loz": 0x25CA,
+            "spades": 0x2660,
+            "clubs": 0x2663,
+            "hearts": 0x2665,
+            "diams": 0x2666
+        });
+    }
+}

src/compiler/transformers/module/es6.ts

@@ -0,0 +1,144 @@
+/// <reference path="../../factory.ts" />
+/// <reference path="../../visitor.ts" />
+
+/*@internal*/
+namespace ts {
+    export function transformES6Module(context: TransformationContext) {
+        const compilerOptions = context.getCompilerOptions();
+        const resolver = context.getEmitResolver();
+
+        let currentSourceFile: SourceFile;
+
+        return transformSourceFile;
+
+        function transformSourceFile(node: SourceFile) {
+            if (isDeclarationFile(node)) {
+                return node;
+            }
+
+            if (isExternalModule(node) || compilerOptions.isolatedModules) {
+                currentSourceFile = node;
+                return visitEachChild(node, visitor, context);
+            }
+            return node;
+        }
+
+        function visitor(node: Node): VisitResult<Node> {
+            switch (node.kind) {
+                case SyntaxKind.ImportDeclaration:
+                    return visitImportDeclaration(<ImportDeclaration>node);
+                case SyntaxKind.ImportEqualsDeclaration:
+                    return visitImportEqualsDeclaration(<ImportEqualsDeclaration>node);
+                case SyntaxKind.ImportClause:
+                    return visitImportClause(<ImportClause>node);
+                case SyntaxKind.NamedImports:
+                case SyntaxKind.NamespaceImport:
+                    return visitNamedBindings(<NamedImportBindings>node);
+                case SyntaxKind.ImportSpecifier:
+                    return visitImportSpecifier(<ImportSpecifier>node);
+                case SyntaxKind.ExportAssignment:
+                    return visitExportAssignment(<ExportAssignment>node);
+                case SyntaxKind.ExportDeclaration:
+                    return visitExportDeclaration(<ExportDeclaration>node);
+                case SyntaxKind.NamedExports:
+                    return visitNamedExports(<NamedExports>node);
+                case SyntaxKind.ExportSpecifier:
+                    return visitExportSpecifier(<ExportSpecifier>node);
+            }
+
+            return node;
+        }
+
+        function visitExportAssignment(node: ExportAssignment): ExportAssignment {
+            if (node.isExportEquals) {
+                return undefined; // do not emit export equals for ES6
+            }
+            const original = getOriginalNode(node);
+            return nodeIsSynthesized(original) || resolver.isValueAliasDeclaration(original) ? node : undefined;
+        }
+
+        function visitExportDeclaration(node: ExportDeclaration): ExportDeclaration {
+            if (!node.exportClause) {
+                return resolver.moduleExportsSomeValue(node.moduleSpecifier) ? node : undefined;
+            }
+            if (!resolver.isValueAliasDeclaration(node)) {
+                return undefined;
+            }
+            const newExportClause = visitNode(node.exportClause, visitor, isNamedExports, /*optional*/ true);
+            if (node.exportClause === newExportClause) {
+                return node;
+            }
+            return newExportClause
+                ? createExportDeclaration(
+                    /*decorators*/ undefined,
+                    /*modifiers*/ undefined,
+                    newExportClause,
+                    node.moduleSpecifier)
+                : undefined;
+        }
+
+        function visitNamedExports(node: NamedExports): NamedExports {
+            const newExports = visitNodes(node.elements, visitor, isExportSpecifier);
+            if (node.elements === newExports) {
+                return node;
+            }
+            return newExports.length ? createNamedExports(newExports) : undefined;
+        }
+
+        function visitExportSpecifier(node: ExportSpecifier): ExportSpecifier {
+            return resolver.isValueAliasDeclaration(node) ? node : undefined;
+        }
+
+        function visitImportEqualsDeclaration(node: ImportEqualsDeclaration): ImportEqualsDeclaration {
+            return !isExternalModuleImportEqualsDeclaration(node) || resolver.isReferencedAliasDeclaration(node) ? node : undefined;
+        }
+
+        function visitImportDeclaration(node: ImportDeclaration) {
+            if (node.importClause) {
+                const newImportClause = visitNode(node.importClause, visitor, isImportClause);
+                if (!newImportClause.name && !newImportClause.namedBindings) {
+                    return undefined;
+                }
+                else if (newImportClause !== node.importClause) {
+                    return createImportDeclaration(
+                        /*decorators*/ undefined,
+                        /*modifiers*/ undefined,
+                        newImportClause,
+                        node.moduleSpecifier);
+                }
+            }
+            return node;
+        }
+
+        function visitImportClause(node: ImportClause): ImportClause {
+            let newDefaultImport = node.name;
+            if (!resolver.isReferencedAliasDeclaration(node)) {
+                newDefaultImport = undefined;
+            }
+            const newNamedBindings = visitNode(node.namedBindings, visitor, isNamedImportBindings, /*optional*/ true);
+            return newDefaultImport !== node.name || newNamedBindings !== node.namedBindings
+                ? createImportClause(newDefaultImport, newNamedBindings)
+                : node;
+        }
+
+        function visitNamedBindings(node: NamedImportBindings): VisitResult<NamedImportBindings> {
+            if (node.kind === SyntaxKind.NamespaceImport) {
+                return resolver.isReferencedAliasDeclaration(node) ? node : undefined;
+            }
+            else {
+                const newNamedImportElements = visitNodes((<NamedImports>node).elements, visitor, isImportSpecifier);
+                if (!newNamedImportElements || newNamedImportElements.length == 0) {
+                    return undefined;
+                }
+                if (newNamedImportElements === (<NamedImports>node).elements) {
+                    return node;
+                }
+                return createNamedImports(newNamedImportElements);
+            }
+        }
+
+        function visitImportSpecifier(node: ImportSpecifier) {
+            return resolver.isReferencedAliasDeclaration(node) ? node : undefined;
+        }
+    }
+}

src/compiler/tsc.ts

@@ -6,6 +6,11 @@ namespace ts {
         fileWatcher?: FileWatcher;
     }
 
+    interface Statistic {
+        name: string;
+        value: string;
+    }
+
     const defaultFormatDiagnosticsHost: FormatDiagnosticsHost = {
         getCurrentDirectory: () => sys.getCurrentDirectory(),
         getNewLine: () => sys.newLine,
@@ -230,18 +235,6 @@ namespace ts {
         return s;
     }
 
-    function reportStatisticalValue(name: string, value: string) {
-        sys.write(padRight(name + ":", 12) + padLeft(value.toString(), 10) + sys.newLine);
-    }
-
-    function reportCountStatistic(name: string, count: number) {
-        reportStatisticalValue(name, "" + count);
-    }
-
-    function reportTimeStatistic(name: string, time: number) {
-        reportStatisticalValue(name, (time / 1000).toFixed(2) + "s");
-    }
-
     function isJSONSupported() {
         return typeof JSON === "object" && typeof JSON.parse === "function";
     }
@@ -489,10 +482,7 @@ namespace ts {
             sourceFile.fileWatcher.close();
             sourceFile.fileWatcher = undefined;
             if (removed) {
-                const index = rootFileNames.indexOf(sourceFile.fileName);
-                if (index >= 0) {
-                    rootFileNames.splice(index, 1);
-                }
+                unorderedRemoveItem(rootFileNames, sourceFile.fileName);
             }
             startTimerForRecompilation();
         }
@@ -550,7 +540,11 @@ namespace ts {
 
     function compile(fileNames: string[], compilerOptions: CompilerOptions, compilerHost: CompilerHost) {
         const hasDiagnostics = compilerOptions.diagnostics || compilerOptions.extendedDiagnostics;
-        if (hasDiagnostics) performance.enable();
+        let statistics: Statistic[];
+        if (hasDiagnostics) {
+            performance.enable();
+            statistics = [];
+        }
 
         const program = createProgram(fileNames, compilerOptions, compilerHost);
         const exitStatus = compileProgram();
@@ -594,6 +588,7 @@ namespace ts {
                 reportTimeStatistic("Emit time", emitTime);
             }
             reportTimeStatistic("Total time", programTime + bindTime + checkTime + emitTime);
+            reportStatistics();
 
             performance.disable();
         }
@@ -635,6 +630,36 @@ namespace ts {
             }
             return ExitStatus.Success;
         }
+
+        function reportStatistics() {
+            let nameSize = 0;
+            let valueSize = 0;
+            for (const { name, value } of statistics) {
+                if (name.length > nameSize) {
+                    nameSize = name.length;
+                }
+
+                if (value.length > valueSize) {
+                    valueSize = value.length;
+                }
+            }
+
+            for (const { name, value } of statistics) {
+                sys.write(padRight(name + ":", nameSize + 2) + padLeft(value.toString(), valueSize) + sys.newLine);
+            }
+        }
+
+        function reportStatisticalValue(name: string, value: string) {
+            statistics.push({ name, value });
+        }
+
+        function reportCountStatistic(name: string, count: number) {
+            reportStatisticalValue(name, "" + count);
+        }
+
+        function reportTimeStatistic(name: string, time: number) {
+            reportStatisticalValue(name, (time / 1000).toFixed(2) + "s");
+        }
     }
 
     function printVersion() {
@@ -642,7 +667,7 @@ namespace ts {
     }
 
     function printHelp() {
-        let output = "";
+        const output: string[] = [];
 
         // We want to align our "syntax" and "examples" commands to a certain margin.
         const syntaxLength = getDiagnosticText(Diagnostics.Syntax_Colon_0, "").length;
@@ -653,17 +678,17 @@ namespace ts {
         let syntax = makePadding(marginLength - syntaxLength);
         syntax += "tsc [" + getDiagnosticText(Diagnostics.options) + "] [" + getDiagnosticText(Diagnostics.file) + " ...]";
 
-        output += getDiagnosticText(Diagnostics.Syntax_Colon_0, syntax);
-        output += sys.newLine + sys.newLine;
+        output.push(getDiagnosticText(Diagnostics.Syntax_Colon_0, syntax));
+        output.push(sys.newLine + sys.newLine);
 
         // Build up the list of examples.
         const padding = makePadding(marginLength);
-        output += getDiagnosticText(Diagnostics.Examples_Colon_0, makePadding(marginLength - examplesLength) + "tsc hello.ts") + sys.newLine;
-        output += padding + "tsc --outFile file.js file.ts" + sys.newLine;
-        output += padding + "tsc @args.txt" + sys.newLine;
-        output += sys.newLine;
+        output.push(getDiagnosticText(Diagnostics.Examples_Colon_0, makePadding(marginLength - examplesLength) + "tsc hello.ts") + sys.newLine);
+        output.push(padding + "tsc --outFile file.js file.ts" + sys.newLine);
+        output.push(padding + "tsc @args.txt" + sys.newLine);
+        output.push(sys.newLine);
 
-        output += getDiagnosticText(Diagnostics.Options_Colon) + sys.newLine;
+        output.push(getDiagnosticText(Diagnostics.Options_Colon) + sys.newLine);
 
         // Sort our options by their names, (e.g. "--noImplicitAny" comes before "--watch")
         const optsList = filter(optionDeclarations.slice(), v => !v.experimental);
@@ -730,18 +755,20 @@ namespace ts {
             const usage = usageColumn[i];
             const description = descriptionColumn[i];
             const kindsList = optionsDescriptionMap[description];
-            output += usage + makePadding(marginLength - usage.length + 2) + description + sys.newLine;
+            output.push(usage + makePadding(marginLength - usage.length + 2) + description + sys.newLine);
 
             if (kindsList) {
-                output += makePadding(marginLength + 4);
+                output.push(makePadding(marginLength + 4));
                 for (const kind of kindsList) {
-                    output += kind + " ";
+                    output.push(kind + " ");
                 }
-                output += sys.newLine;
+                output.push(sys.newLine);
             }
         }
 
-        sys.write(output);
+        for (const line of output) {
+            sys.write(line);
+        }
         return;
 
         function getParamType(option: CommandLineOption) {
@@ -763,68 +790,16 @@ namespace ts {
             reportDiagnostic(createCompilerDiagnostic(Diagnostics.A_tsconfig_json_file_is_already_defined_at_Colon_0, file), /* host */ undefined);
         }
         else {
-            const compilerOptions = extend(options, defaultInitCompilerOptions);
-            const configurations: any = {
-                compilerOptions: serializeCompilerOptions(compilerOptions)
-            };
-
-            if (fileNames && fileNames.length) {
-                // only set the files property if we have at least one file
-                configurations.files = fileNames;
-            }
-            else {
-                configurations.exclude = ["node_modules"];
-                if (compilerOptions.outDir) {
-                    configurations.exclude.push(compilerOptions.outDir);
-                }
-            }
-
-            sys.writeFile(file, JSON.stringify(configurations, undefined, 4));
+            sys.writeFile(file, JSON.stringify(generateTSConfig(options, fileNames), undefined, 4));
             reportDiagnostic(createCompilerDiagnostic(Diagnostics.Successfully_created_a_tsconfig_json_file), /* host */ undefined);
         }
 
         return;
-
-        function serializeCompilerOptions(options: CompilerOptions): Map<string | number | boolean> {
-            const result = createMap<string | number | boolean>();
-            const optionsNameMap = getOptionNameMap().optionNameMap;
-
-            for (const name in options) {
-                if (hasProperty(options, name)) {
-                    // tsconfig only options cannot be specified via command line,
-                    // so we can assume that only types that can appear here string | number | boolean
-                    const value = <string | number | boolean>options[name];
-                    switch (name) {
-                        case "init":
-                        case "watch":
-                        case "version":
-                        case "help":
-                        case "project":
-                            break;
-                        default:
-                            let optionDefinition = optionsNameMap[name.toLowerCase()];
-                            if (optionDefinition) {
-                                if (typeof optionDefinition.type === "string") {
-                                    // string, number or boolean
-                                    result[name] = value;
-                                }
-                                else {
-                                    // Enum
-                                    const typeMap = <Map<number>>optionDefinition.type;
-                                    for (const key in typeMap) {
-                                        if (typeMap[key] === value) {
-                                            result[name] = key;
-                                        }
-                                    }
-                                }
-                            }
-                            break;
-                    }
-                }
-            }
-            return result;
-        }
     }
 }
 
+if (ts.sys.tryEnableSourceMapsForHost && /^development$/i.test(ts.sys.getEnvironmentVariable("NODE_ENV"))) {
+    ts.sys.tryEnableSourceMapsForHost();
+}
+
 ts.executeCommandLine(ts.sys.args);

src/compiler/tsconfig.json

@@ -20,6 +20,19 @@
         "utilities.ts",
         "binder.ts",
         "checker.ts",
+        "factory.ts",
+        "visitor.ts",
+        "transformers/ts.ts",
+        "transformers/jsx.ts",
+        "transformers/es7.ts",
+        "transformers/es6.ts",
+        "transformers/generators.ts",
+        "transformers/destructuring.ts",
+        "transformers/module/module.ts",
+        "transformers/module/system.ts",
+        "transformers/module/es6.ts",
+        "transformer.ts",
+        "comments.ts",
         "sourcemap.ts",
         "declarationEmitter.ts",
         "emitter.ts",

src/compiler/types.ts

@@ -19,6 +19,7 @@ namespace ts {
         remove(fileName: Path): void;
 
         forEachValue(f: (key: Path, v: T) => void): void;
+        getKeys(): Path[];
         clear(): void;
     }
 
@@ -351,14 +352,24 @@ namespace ts {
         JSDocPropertyTag,
         JSDocTypeLiteral,
         JSDocLiteralType,
+        JSDocNullKeyword,
+        JSDocUndefinedKeyword,
+        JSDocNeverKeyword,
 
         // Synthesized list
         SyntaxList,
+
+        // Transformation nodes
+        NotEmittedStatement,
+        PartiallyEmittedExpression,
+
         // Enum value count
         Count,
         // Markers
         FirstAssignment = EqualsToken,
         LastAssignment = CaretEqualsToken,
+        FirstCompoundAssignment = PlusEqualsToken,
+        LastCompoundAssignment = CaretEqualsToken,
         FirstReservedWord = BreakKeyword,
         LastReservedWord = WithKeyword,
         FirstKeyword = BreakKeyword,
@@ -383,10 +394,51 @@ namespace ts {
         FirstJSDocNode = JSDocTypeExpression,
         LastJSDocNode = JSDocLiteralType,
         FirstJSDocTagNode = JSDocComment,
-        LastJSDocTagNode = JSDocLiteralType
+        LastJSDocTagNode = JSDocNeverKeyword
     }
 
     export const enum NodeFlags {
+        None =               0,
+        Let =                1 << 0,  // Variable declaration
+        Const =              1 << 1,  // Variable declaration
+        NestedNamespace =    1 << 2,  // Namespace declaration
+        Synthesized =        1 << 3,  // Node was synthesized during transformation
+        Namespace =          1 << 4,  // Namespace declaration
+        ExportContext =      1 << 5,  // Export context (initialized by binding)
+        ContainsThis =       1 << 6,  // Interface contains references to "this"
+        HasImplicitReturn =  1 << 7,  // If function implicitly returns on one of codepaths (initialized by binding)
+        HasExplicitReturn =  1 << 8,  // If function has explicit reachable return on one of codepaths (initialized by binding)
+        GlobalAugmentation = 1 << 9,  // Set if module declaration is an augmentation for the global scope
+        HasClassExtends =    1 << 10, // If the file has a non-ambient class with an extends clause in ES5 or lower (initialized by binding)
+        HasDecorators =      1 << 11, // If the file has decorators (initialized by binding)
+        HasParamDecorators = 1 << 12, // If the file has parameter decorators (initialized by binding)
+        HasAsyncFunctions =  1 << 13, // If the file has async functions (initialized by binding)
+        HasJsxSpreadAttributes = 1 << 14, // If the file as JSX spread attributes (initialized by binding)
+        DisallowInContext =  1 << 15, // If node was parsed in a context where 'in-expressions' are not allowed
+        YieldContext =       1 << 16, // If node was parsed in the 'yield' context created when parsing a generator
+        DecoratorContext =   1 << 17, // If node was parsed as part of a decorator
+        AwaitContext =       1 << 18, // If node was parsed in the 'await' context created when parsing an async function
+        ThisNodeHasError =   1 << 19, // If the parser encountered an error when parsing the code that created this node
+        JavaScriptFile =     1 << 20, // If node was parsed in a JavaScript
+        ThisNodeOrAnySubNodesHasError = 1 << 21, // If this node or any of its children had an error
+        HasAggregatedChildData = 1 << 22, // If we've computed data from children and cached it in this node
+
+        BlockScoped = Let | Const,
+
+        ReachabilityCheckFlags = HasImplicitReturn | HasExplicitReturn,
+        EmitHelperFlags = HasClassExtends | HasDecorators | HasParamDecorators | HasAsyncFunctions | HasJsxSpreadAttributes,
+        ReachabilityAndEmitFlags = ReachabilityCheckFlags | EmitHelperFlags,
+
+        // Parsing context flags
+        ContextFlags = DisallowInContext | YieldContext | DecoratorContext | AwaitContext | JavaScriptFile,
+
+        // Exclude these flags when parsing a Type
+        TypeExcludesFlags = YieldContext | AwaitContext,
+    }
+
+    export type ModifiersArray = NodeArray<Modifier>;
+
+    export const enum ModifierFlags {
         None =               0,
         Export =             1 << 0,  // Declarations
         Ambient =            1 << 1,  // Declarations
@@ -398,43 +450,14 @@ namespace ts {
         Abstract =           1 << 7,  // Class/Method/ConstructSignature
         Async =              1 << 8,  // Property/Method/Function
         Default =            1 << 9,  // Function/Class (export default declaration)
-        Let =                1 << 10,  // Variable declaration
-        Const =              1 << 11,  // Variable declaration
-        Namespace =          1 << 12,  // Namespace declaration
-        ExportContext =      1 << 13,  // Export context (initialized by binding)
-        ContainsThis =       1 << 14,  // Interface contains references to "this"
-        HasImplicitReturn =  1 << 15,  // If function implicitly returns on one of codepaths (initialized by binding)
-        HasExplicitReturn =  1 << 16,  // If function has explicit reachable return on one of codepaths (initialized by binding)
-        GlobalAugmentation = 1 << 17,  // Set if module declaration is an augmentation for the global scope
-        HasClassExtends =    1 << 18,  // If the file has a non-ambient class with an extends clause in ES5 or lower (initialized by binding)
-        HasDecorators =      1 << 19,  // If the file has decorators (initialized by binding)
-        HasParamDecorators = 1 << 20,  // If the file has parameter decorators (initialized by binding)
-        HasAsyncFunctions =  1 << 21,  // If the file has async functions (initialized by binding)
-        DisallowInContext =  1 << 22,  // If node was parsed in a context where 'in-expressions' are not allowed
-        YieldContext =       1 << 23,  // If node was parsed in the 'yield' context created when parsing a generator
-        DecoratorContext =   1 << 24,  // If node was parsed as part of a decorator
-        AwaitContext =       1 << 25,  // If node was parsed in the 'await' context created when parsing an async function
-        ThisNodeHasError =   1 << 26,  // If the parser encountered an error when parsing the code that created this node
-        JavaScriptFile =     1 << 27,  // If node was parsed in a JavaScript
-        ThisNodeOrAnySubNodesHasError = 1 << 28,  // If this node or any of its children had an error
-        HasAggregatedChildData = 1 << 29,  // If we've computed data from children and cached it in this node
-        HasJsxSpreadAttribute = 1 << 30,
+        Const =              1 << 11, // Variable declaration
+
+        HasComputedFlags =   1 << 29, // Modifier flags have been computed
 
-        Modifier = Export | Ambient | Public | Private | Protected | Static | Abstract | Default | Async | Readonly,
         AccessibilityModifier = Public | Private | Protected,
         // Accessibility modifiers and 'readonly' can be attached to a parameter in a constructor to make it a property.
         ParameterPropertyModifier = AccessibilityModifier | Readonly,
-        BlockScoped = Let | Const,
-
-        ReachabilityCheckFlags = HasImplicitReturn | HasExplicitReturn,
-        EmitHelperFlags = HasClassExtends | HasDecorators | HasParamDecorators | HasAsyncFunctions,
-        ReachabilityAndEmitFlags = ReachabilityCheckFlags | EmitHelperFlags,
-
-        // Parsing context flags
-        ContextFlags = DisallowInContext | YieldContext | DecoratorContext | AwaitContext | JavaScriptFile,
-
-        // Exclude these flags when parsing a Type
-        TypeExcludesFlags = YieldContext | AwaitContext,
+        NonPublicAccessibilityModifier = Private | Protected,
     }
 
     export const enum JsxFlags {
@@ -457,26 +480,27 @@ namespace ts {
     export interface Node extends TextRange {
         kind: SyntaxKind;
         flags: NodeFlags;
+        /* @internal */ modifierFlagsCache?: ModifierFlags;
+        /* @internal */ transformFlags?: TransformFlags;
         decorators?: NodeArray<Decorator>;              // Array of decorators (in document order)
         modifiers?: ModifiersArray;                     // Array of modifiers
         /* @internal */ id?: number;                    // Unique id (used to look up NodeLinks)
-        parent?: Node;                                  // Parent node (initialized by binding
-        /* @internal */ jsDocComments?: JSDocComment[]; // JSDoc for the node, if it has any.  Only for .js files.
+        parent?: Node;                                  // Parent node (initialized by binding)
+        /* @internal */ original?: Node;                // The original node if this is an updated node.
+        /* @internal */ startsOnNewLine?: boolean;      // Whether a synthesized node should start on a new line (used by transforms).
+        /* @internal */ jsDocComments?: JSDoc[];        // JSDoc for the node, if it has any.
         /* @internal */ symbol?: Symbol;                // Symbol declared by node (initialized by binding)
         /* @internal */ locals?: SymbolTable;           // Locals associated with node (initialized by binding)
         /* @internal */ nextContainer?: Node;           // Next container in declaration order (initialized by binding)
         /* @internal */ localSymbol?: Symbol;           // Local symbol declared by node (initialized by binding only for exported nodes)
         /* @internal */ flowNode?: FlowNode;            // Associated FlowNode (initialized by binding)
+        /* @internal */ emitNode?: EmitNode;            // Associated EmitNode (initialized by transforms)
     }
 
-    export interface NodeArray<T> extends Array<T>, TextRange {
+    export interface NodeArray<T extends Node> extends Array<T>, TextRange {
         hasTrailingComma?: boolean;
     }
 
-    export interface ModifiersArray extends NodeArray<Modifier> {
-        flags: NodeFlags;
-    }
-
     export interface Token extends Node {
         __tokenTag: any;
     }
@@ -493,10 +517,26 @@ namespace ts {
     // @kind(SyntaxKind.StaticKeyword)
     export interface Modifier extends Token { }
 
+    /*@internal*/
+    export const enum GeneratedIdentifierKind {
+        None,   // Not automatically generated.
+        Auto,   // Automatically generated identifier.
+        Loop,   // Automatically generated identifier with a preference for '_i'.
+        Unique, // Unique name based on the 'text' property.
+        Node,   // Unique name based on the node in the 'original' property.
+    }
+
     // @kind(SyntaxKind.Identifier)
     export interface Identifier extends PrimaryExpression {
         text: string;                                  // Text of identifier (with escapes converted to characters)
         originalKeywordKind?: SyntaxKind;              // Original syntaxKind which get set so that we can report an error later
+        /*@internal*/ autoGenerateKind?: GeneratedIdentifierKind; // Specifies whether to auto-generate the text for an identifier.
+        /*@internal*/ autoGenerateId?: number;         // Ensures unique generated identifiers get unique names, but clones get the same name.
+    }
+
+    // Transient identifier node (marked by id === -1)
+    export interface TransientIdentifier extends Identifier {
+        resolvedSymbol: Symbol;
     }
 
     // @kind(SyntaxKind.QualifiedName)
@@ -553,10 +593,12 @@ namespace ts {
     // @kind(SyntaxKind.ConstructSignature)
     export interface ConstructSignatureDeclaration extends SignatureDeclaration, TypeElement { }
 
+    export type BindingName = Identifier | BindingPattern;
+
     // @kind(SyntaxKind.VariableDeclaration)
     export interface VariableDeclaration extends Declaration {
         parent?: VariableDeclarationList;
-        name: Identifier | BindingPattern;  // Declared variable name
+        name: BindingName;                  // Declared variable name
         type?: TypeNode;                    // Optional type annotation
         initializer?: Expression;           // Optional initializer
     }
@@ -569,7 +611,7 @@ namespace ts {
     // @kind(SyntaxKind.Parameter)
     export interface ParameterDeclaration extends Declaration {
         dotDotDotToken?: Node;              // Present on rest parameter
-        name: Identifier | BindingPattern;  // Declared parameter name
+        name: BindingName;                  // Declared parameter name
         questionToken?: Node;               // Present on optional parameter
         type?: TypeNode;                    // Optional type annotation
         initializer?: Expression;           // Optional initializer
@@ -579,7 +621,7 @@ namespace ts {
     export interface BindingElement extends Declaration {
         propertyName?: PropertyName;        // Binding property name (in object binding pattern)
         dotDotDotToken?: Node;              // Present on rest binding element
-        name: Identifier | BindingPattern;  // Declared binding element name
+        name: BindingName;                  // Declared binding element name
         initializer?: Expression;           // Optional initializer
     }
 
@@ -604,6 +646,8 @@ namespace ts {
         name?: PropertyName;
    }
 
+    export type ObjectLiteralElementLike = PropertyAssignment | ShorthandPropertyAssignment | MethodDeclaration | AccessorDeclaration;
+
     // @kind(SyntaxKind.PropertyAssignment)
     export interface PropertyAssignment extends ObjectLiteralElement {
         _propertyAssignmentBrand: any;
@@ -644,14 +688,20 @@ namespace ts {
     }
 
     export interface BindingPattern extends Node {
-        elements: NodeArray<BindingElement>;
+        elements: NodeArray<BindingElement | ArrayBindingElement>;
     }
 
     // @kind(SyntaxKind.ObjectBindingPattern)
-    export interface ObjectBindingPattern extends BindingPattern { }
+    export interface ObjectBindingPattern extends BindingPattern {
+        elements: NodeArray<BindingElement>;
+    }
+
+    export type ArrayBindingElement = BindingElement | OmittedExpression;
 
     // @kind(SyntaxKind.ArrayBindingPattern)
-    export interface ArrayBindingPattern extends BindingPattern { }
+    export interface ArrayBindingPattern extends BindingPattern {
+        elements: NodeArray<ArrayBindingElement>;
+    }
 
     /**
      * Several node kinds share function-like features such as a signature,
@@ -807,6 +857,8 @@ namespace ts {
     // @kind(SyntaxKind.StringLiteral)
     export interface StringLiteral extends LiteralExpression {
         _stringLiteralBrand: any;
+        /* @internal */
+        textSourceNode?: Identifier | StringLiteral; // Allows a StringLiteral to get its text from another node (used by transforms).
     }
 
     // Note: 'brands' in our syntax nodes serve to give us a small amount of nominal typing.
@@ -822,7 +874,17 @@ namespace ts {
     }
 
     // @kind(SyntaxKind.OmittedExpression)
-    export interface OmittedExpression extends Expression { }
+    export interface OmittedExpression extends Expression {
+        _omittedExpressionBrand: any;
+    }
+
+    // Represents an expression that is elided as part of a transformation to emit comments on a
+    // not-emitted node. The 'expression' property of a NotEmittedExpression should be emitted.
+    // @internal
+    // @kind(SyntaxKind.NotEmittedExpression)
+    export interface PartiallyEmittedExpression extends LeftHandSideExpression {
+        expression: Expression;
+    }
 
     export interface UnaryExpression extends Expression {
         _unaryExpressionBrand: any;
@@ -934,13 +996,18 @@ namespace ts {
     // The text property of a LiteralExpression stores the interpreted value of the literal in text form. For a StringLiteral,
     // or any literal of a template, this means quotes have been removed and escapes have been converted to actual characters.
     // For a NumericLiteral, the stored value is the toString() representation of the number. For example 1, 1.00, and 1e0 are all stored as just "1".
-    // @kind(SyntaxKind.NumericLiteral)
     // @kind(SyntaxKind.RegularExpressionLiteral)
     // @kind(SyntaxKind.NoSubstitutionTemplateLiteral)
     export interface LiteralExpression extends LiteralLikeNode, PrimaryExpression {
         _literalExpressionBrand: any;
     }
 
+    // @kind(SyntaxKind.NumericLiteral)
+    export interface NumericLiteral extends LiteralExpression {
+        _numericLiteralBrand: any;
+        trailingComment?: string;
+    }
+
     // @kind(SyntaxKind.TemplateHead)
     // @kind(SyntaxKind.TemplateMiddle)
     // @kind(SyntaxKind.TemplateTail)
@@ -948,6 +1015,8 @@ namespace ts {
         _templateLiteralFragmentBrand: any;
     }
 
+    export type Template = TemplateExpression | LiteralExpression;
+
     // @kind(SyntaxKind.TemplateExpression)
     export interface TemplateExpression extends PrimaryExpression {
         head: TemplateLiteralFragment;
@@ -979,10 +1048,19 @@ namespace ts {
         expression: Expression;
     }
 
+    /**
+      * This interface is a base interface for ObjectLiteralExpression and JSXAttributes to extend from. JSXAttributes is similar to
+      * ObjectLiteralExpression in that it contains array of properties; however, JSXAttributes' properties can only be
+      * JSXAttribute or JSXSpreadAttribute. ObjectLiteralExpression, on the other hand, can only have properties of type
+      * ObjectLiteralElement (e.g. PropertyAssignment, ShorthandPropertyAssignment etc.)
+     **/
+    export interface ObjectLiteralExpressionBase<T extends ObjectLiteralElement> extends PrimaryExpression, Declaration {
+        properties: NodeArray<T>;
+    }
+
     // An ObjectLiteralExpression is the declaration node for an anonymous symbol.
     // @kind(SyntaxKind.ObjectLiteralExpression)
-    export interface ObjectLiteralExpression extends PrimaryExpression, Declaration {
-        properties: NodeArray<ObjectLiteralElement>;
+    export interface ObjectLiteralExpression extends ObjectLiteralExpressionBase<ObjectLiteralElementLike> {
         /* @internal */
         multiLine?: boolean;
     }
@@ -1026,7 +1104,7 @@ namespace ts {
     // @kind(SyntaxKind.TaggedTemplateExpression)
     export interface TaggedTemplateExpression extends MemberExpression {
         tag: LeftHandSideExpression;
-        template: LiteralExpression | TemplateExpression;
+        template: Template;
     }
 
     export type CallLikeExpression = CallExpression | NewExpression | TaggedTemplateExpression | Decorator;
@@ -1077,11 +1155,13 @@ namespace ts {
     /// Either the opening tag in a <Tag>...</Tag> pair, or the lone <Tag /> in a self-closing form
     export type JsxOpeningLikeElement = JsxSelfClosingElement | JsxOpeningElement;
 
+    export type JsxAttributeLike = JsxAttribute | JsxSpreadAttribute;
+
     // @kind(SyntaxKind.JsxAttribute)
     export interface JsxAttribute extends Node {
         name: Identifier;
         /// JSX attribute initializers are optional; <X y /> is sugar for <X y={true} />
-        initializer?: Expression;
+        initializer?: StringLiteral | JsxExpression;
     }
 
     // @kind(SyntaxKind.JsxSpreadAttribute)
@@ -1110,6 +1190,13 @@ namespace ts {
         _statementBrand: any;
     }
 
+    // Represents a statement that is elided as part of a transformation to emit comments on a
+    // not-emitted node.
+    // @internal
+    // @kind(SyntaxKind.NotEmittedStatement)
+    export interface NotEmittedStatement extends Statement {
+    }
+
     // @kind(SyntaxKind.EmptyStatement)
     export interface EmptyStatement extends Statement { }
 
@@ -1126,6 +1213,7 @@ namespace ts {
     // @kind(SyntaxKind.Block)
     export interface Block extends Statement {
         statements: NodeArray<Statement>;
+        /*@internal*/ multiLine?: boolean;
     }
 
     // @kind(SyntaxKind.VariableStatement)
@@ -1159,22 +1247,24 @@ namespace ts {
         expression: Expression;
     }
 
+    export type ForInitializer = VariableDeclarationList | Expression;
+
     // @kind(SyntaxKind.ForStatement)
     export interface ForStatement extends IterationStatement {
-        initializer?: VariableDeclarationList | Expression;
+        initializer?: ForInitializer;
         condition?: Expression;
         incrementor?: Expression;
     }
 
     // @kind(SyntaxKind.ForInStatement)
     export interface ForInStatement extends IterationStatement {
-        initializer: VariableDeclarationList | Expression;
+        initializer: ForInitializer;
         expression: Expression;
     }
 
     // @kind(SyntaxKind.ForOfStatement)
     export interface ForOfStatement extends IterationStatement {
-        initializer: VariableDeclarationList | Expression;
+        initializer: ForInitializer;
         expression: Expression;
     }
 
@@ -1304,7 +1394,7 @@ namespace ts {
     export interface EnumMember extends Declaration {
         // This does include ComputedPropertyName, but the parser will give an error
         // if it parses a ComputedPropertyName in an EnumMember
-        name: DeclarationName;
+        name: PropertyName;
         initializer?: Expression;
     }
 
@@ -1316,6 +1406,8 @@ namespace ts {
 
     export type ModuleBody = ModuleBlock | ModuleDeclaration;
 
+    export type ModuleName = Identifier | StringLiteral;
+
     // @kind(SyntaxKind.ModuleDeclaration)
     export interface ModuleDeclaration extends DeclarationStatement {
         name: Identifier | LiteralExpression;
@@ -1327,13 +1419,15 @@ namespace ts {
         statements: NodeArray<Statement>;
     }
 
+    export type ModuleReference = EntityName | ExternalModuleReference;
+
     // @kind(SyntaxKind.ImportEqualsDeclaration)
     export interface ImportEqualsDeclaration extends DeclarationStatement {
         name: Identifier;
 
         // 'EntityName' for an internal module reference, 'ExternalModuleReference' for an external
         // module reference.
-        moduleReference: EntityName | ExternalModuleReference;
+        moduleReference: ModuleReference;
     }
 
     // @kind(SyntaxKind.ExternalModuleReference)
@@ -1351,6 +1445,8 @@ namespace ts {
         moduleSpecifier: Expression;
     }
 
+    export type NamedImportBindings = NamespaceImport | NamedImports;
+
     // In case of:
     // import d from "mod" => name = d, namedBinding = undefined
     // import * as ns from "mod" => name = undefined, namedBinding: NamespaceImport = { name: ns }
@@ -1360,7 +1456,7 @@ namespace ts {
     // @kind(SyntaxKind.ImportClause)
     export interface ImportClause extends Declaration {
         name?: Identifier; // Default binding
-        namedBindings?: NamespaceImport | NamedImports;
+        namedBindings?: NamedImportBindings;
     }
 
     // @kind(SyntaxKind.NamespaceImport)
@@ -1468,7 +1564,7 @@ namespace ts {
 
     // @kind(SyntaxKind.JSDocRecordType)
     export interface JSDocRecordType extends JSDocType, TypeLiteralNode {
-        members: NodeArray<JSDocRecordMember>;
+        literal: TypeLiteralNode;
     }
 
     // @kind(SyntaxKind.JSDocTypeReference)
@@ -1516,14 +1612,16 @@ namespace ts {
     }
 
     // @kind(SyntaxKind.JSDocComment)
-    export interface JSDocComment extends Node {
-        tags: NodeArray<JSDocTag>;
+    export interface JSDoc extends Node {
+        tags: NodeArray<JSDocTag> | undefined;
+        comment: string | undefined;
     }
 
     // @kind(SyntaxKind.JSDocTag)
     export interface JSDocTag extends Node {
         atToken: Node;
         tagName: Identifier;
+        comment: string | undefined;
     }
 
     // @kind(SyntaxKind.JSDocTemplateTag)
@@ -1562,9 +1660,13 @@ namespace ts {
 
     // @kind(SyntaxKind.JSDocParameterTag)
     export interface JSDocParameterTag extends JSDocTag {
+        /** the parameter name, if provided *before* the type (TypeScript-style) */
         preParameterName?: Identifier;
         typeExpression?: JSDocTypeExpression;
+        /** the parameter name, if provided *after* the type (JSDoc-standard) */
         postParameterName?: Identifier;
+        /** the parameter name, regardless of the location it was provided */
+        parameterName: Identifier;
         isBracketed: boolean;
     }
 
@@ -1699,6 +1801,8 @@ namespace ts {
         /* @internal */ imports: LiteralExpression[];
         /* @internal */ moduleAugmentations: LiteralExpression[];
         /* @internal */ patternAmbientModules?: PatternAmbientModule[];
+        // The synthesized identifier for an imported external helpers module.
+        /* @internal */ externalHelpersModuleName?: Identifier;
     }
 
     export interface ScriptReferenceHost {
@@ -1718,6 +1822,8 @@ namespace ts {
           * @param path The path to test.
           */
         fileExists(path: string): boolean;
+
+        readFile(path: string): string;
     }
 
     export interface WriteFileCallback {
@@ -1755,7 +1861,7 @@ namespace ts {
          * used for writing the JavaScript and declaration files.  Otherwise, the writeFile parameter
          * will be invoked when writing the JavaScript and declaration files.
          */
-        emit(targetSourceFile?: SourceFile, writeFile?: WriteFileCallback, cancellationToken?: CancellationToken): EmitResult;
+        emit(targetSourceFile?: SourceFile, writeFile?: WriteFileCallback, cancellationToken?: CancellationToken, emitOnlyDtsFiles?: boolean): EmitResult;
 
         getOptionsDiagnostics(cancellationToken?: CancellationToken): Diagnostic[];
         getGlobalDiagnostics(cancellationToken?: CancellationToken): Diagnostic[];
@@ -1773,6 +1879,7 @@ namespace ts {
         // For testing purposes only.  Should not be used by any other consumers (including the
         // language service).
         /* @internal */ getDiagnosticsProducingTypeChecker(): TypeChecker;
+        /* @internal */ dropDiagnosticsProducingTypeChecker(): void;
 
         /* @internal */ getClassifiableNames(): Map<string>;
 
@@ -1886,6 +1993,7 @@ namespace ts {
         getJsxElementAttributesType(elementNode: JsxOpeningLikeElement): Type;
         getJsxIntrinsicTagNames(): Symbol[];
         isOptionalParameter(node: ParameterDeclaration): boolean;
+        getAmbientModules(): Symbol[];
 
         // Should not be called directly.  Should only be accessed through the Program instance.
         /* @internal */ getDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
@@ -1943,6 +2051,7 @@ namespace ts {
         UseFullyQualifiedType           = 0x00000080,  // Write out the fully qualified type name (eg. Module.Type, instead of Type)
         InFirstTypeArgument             = 0x00000100,  // Writing first type argument of the instantiated type
         InTypeAlias                     = 0x00000200,  // Writing type in type alias declaration
+        UseTypeAliasValue               = 0x00000400,  // Serialize the type instead of using type-alias. This is needed when we emit declaration file.
     }
 
     export const enum SymbolFormatFlags {
@@ -2016,12 +2125,13 @@ namespace ts {
                                             // function that can be reached at runtime (e.g. a `class`
                                             // declaration or a `var` declaration for the static side
                                             // of a type, such as the global `Promise` type in lib.d.ts).
-        VoidType,                           // The TypeReferenceNode resolves to a Void-like type.
+        VoidNullableOrNeverType,            // The TypeReferenceNode resolves to a Void-like, Nullable, or Never type.
         NumberLikeType,                     // The TypeReferenceNode resolves to a Number-like type.
         StringLikeType,                     // The TypeReferenceNode resolves to a String-like type.
         BooleanType,                        // The TypeReferenceNode resolves to a Boolean-like type.
         ArrayLikeType,                      // The TypeReferenceNode resolves to an Array-like type.
         ESSymbolType,                       // The TypeReferenceNode resolves to the ESSymbol type.
+        Promise,                            // The TypeReferenceNode resolved to the global Promise constructor symbol.
         TypeWithCallSignature,              // The TypeReferenceNode resolves to a Function type or a type
                                             // with call signatures.
         ObjectType,                         // The TypeReferenceNode resolves to any other type.
@@ -2030,7 +2140,7 @@ namespace ts {
     /* @internal */
     export interface EmitResolver {
         hasGlobalName(name: string): boolean;
-        getReferencedExportContainer(node: Identifier): SourceFile | ModuleDeclaration | EnumDeclaration;
+        getReferencedExportContainer(node: Identifier, prefixLocals?: boolean): SourceFile | ModuleDeclaration | EnumDeclaration;
         getReferencedImportDeclaration(node: Identifier): Declaration;
         getReferencedDeclarationWithCollidingName(node: Identifier): Declaration;
         isDeclarationWithCollidingName(node: Declaration): boolean;
@@ -2045,18 +2155,20 @@ namespace ts {
         writeReturnTypeOfSignatureDeclaration(signatureDeclaration: SignatureDeclaration, enclosingDeclaration: Node, flags: TypeFormatFlags, writer: SymbolWriter): void;
         writeTypeOfExpression(expr: Expression, enclosingDeclaration: Node, flags: TypeFormatFlags, writer: SymbolWriter): void;
         writeBaseConstructorTypeOfClass(node: ClassLikeDeclaration, enclosingDeclaration: Node, flags: TypeFormatFlags, writer: SymbolWriter): void;
-        isSymbolAccessible(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags): SymbolAccessibilityResult;
+        isSymbolAccessible(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags, shouldComputeAliasToMarkVisible: boolean): SymbolAccessibilityResult;
         isEntityNameVisible(entityName: EntityNameOrEntityNameExpression, enclosingDeclaration: Node): SymbolVisibilityResult;
         // Returns the constant value this property access resolves to, or 'undefined' for a non-constant
         getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): number;
         getReferencedValueDeclaration(reference: Identifier): Declaration;
-        getTypeReferenceSerializationKind(typeName: EntityName): TypeReferenceSerializationKind;
+        getTypeReferenceSerializationKind(typeName: EntityName, location?: Node): TypeReferenceSerializationKind;
         isOptionalParameter(node: ParameterDeclaration): boolean;
         moduleExportsSomeValue(moduleReferenceExpression: Expression): boolean;
         isArgumentsLocalBinding(node: Identifier): boolean;
         getExternalModuleFileFromDeclaration(declaration: ImportEqualsDeclaration | ImportDeclaration | ExportDeclaration | ModuleDeclaration): SourceFile;
         getTypeReferenceDirectivesForEntityName(name: EntityNameOrEntityNameExpression): string[];
         getTypeReferenceDirectivesForSymbol(symbol: Symbol, meaning?: SymbolFlags): string[];
+        isLiteralConstDeclaration(node: VariableDeclaration): boolean;
+        writeLiteralConstValue(node: VariableDeclaration, writer: SymbolWriter): void;
     }
 
     export const enum SymbolFlags {
@@ -2177,7 +2289,8 @@ namespace ts {
         mapper?: TypeMapper;                // Type mapper for instantiation alias
         referenced?: boolean;               // True if alias symbol has been referenced as a value
         containingType?: UnionOrIntersectionType; // Containing union or intersection type for synthetic property
-        hasCommonType?: boolean;            // True if constituents of synthetic property all have same type
+        hasNonUniformType?: boolean;        // True if constituents have non-uniform types
+        isPartial?: boolean;                // True if syntheric property of union type occurs in some but not all constituents
         isDiscriminantProperty?: boolean;   // True if discriminant synthetic property
         resolvedExports?: SymbolTable;      // Resolved exports of module
         exportsChecked?: boolean;           // True if exports of external module have been checked
@@ -2225,6 +2338,8 @@ namespace ts {
         BodyScopedClassBinding              = 0x00100000,  // Binding to a decorated class inside of the class's body.
         NeedsLoopOutParameter               = 0x00200000,  // Block scoped binding whose value should be explicitly copied outside of the converted loop
         AssignmentsMarked                   = 0x00400000,  // Parameter assignments have been marked
+        ClassWithConstructorReference       = 0x00800000,  // Class that contains a binding to its constructor inside of the class body.
+        ConstructorReferenceInClass         = 0x01000000,  // Binding to a class constructor inside of the class's body.
     }
 
     /* @internal */
@@ -2263,7 +2378,7 @@ namespace ts {
         Class                   = 1 << 15,  // Class
         Interface               = 1 << 16,  // Interface
         Reference               = 1 << 17,  // Generic type reference
-        Tuple                   = 1 << 18,  // Tuple
+        Tuple                   = 1 << 18,  // Synthesized generic tuple type
         Union                   = 1 << 19,  // Union (T | U)
         Intersection            = 1 << 20,  // Intersection (T & U)
         Anonymous               = 1 << 21,  // Anonymous
@@ -2271,7 +2386,7 @@ namespace ts {
         /* @internal */
         ObjectLiteral           = 1 << 23,  // Originates in an object literal
         /* @internal */
-        FreshObjectLiteral      = 1 << 24,  // Fresh object literal type
+        FreshLiteral            = 1 << 24,  // Fresh literal type
         /* @internal */
         ContainsWideningType    = 1 << 25,  // Type is or contains undefined or null widening type
         /* @internal */
@@ -2284,6 +2399,7 @@ namespace ts {
         /* @internal */
         Nullable = Undefined | Null,
         Literal = StringLiteral | NumberLiteral | BooleanLiteral | EnumLiteral,
+        StringOrNumberLiteral = StringLiteral | NumberLiteral,
         /* @internal */
         DefinitelyFalsy = StringLiteral | NumberLiteral | BooleanLiteral | Void | Undefined | Null,
         PossiblyFalsy = DefinitelyFalsy | String | Number | Boolean,
@@ -2325,12 +2441,15 @@ namespace ts {
     /* @internal */
     // Intrinsic types (TypeFlags.Intrinsic)
     export interface IntrinsicType extends Type {
-        intrinsicName: string;  // Name of intrinsic type
+        intrinsicName: string;        // Name of intrinsic type
     }
 
     // String literal types (TypeFlags.StringLiteral)
+    // Numeric literal types (TypeFlags.NumberLiteral)
     export interface LiteralType extends Type {
-        text: string;  // Text of string literal
+        text: string;               // Text of literal
+        freshType?: LiteralType;    // Fresh version of type
+        regularType?: LiteralType;  // Regular version of type
     }
 
     // Enum types (TypeFlags.Enum)
@@ -2340,7 +2459,7 @@ namespace ts {
 
     // Enum types (TypeFlags.EnumLiteral)
     export interface EnumLiteralType extends LiteralType {
-        baseType: EnumType & UnionType;
+        baseType: EnumType & UnionType;  // Base enum type
     }
 
     // Object types (TypeFlags.ObjectType)
@@ -2385,11 +2504,6 @@ namespace ts {
         instantiations: Map<TypeReference>;   // Generic instantiation cache
     }
 
-    export interface TupleType extends ObjectType {
-        elementTypes: Type[];  // Element types
-        thisType?: Type;       // This-type of tuple (only needed for tuples that are constraints of type parameters)
-    }
-
     export interface UnionOrIntersectionType extends Type {
         types: Type[];                    // Constituent types
         /* @internal */
@@ -2505,13 +2619,14 @@ namespace ts {
     export interface TypeInferences {
         primary: Type[];    // Inferences made directly to a type parameter
         secondary: Type[];  // Inferences made to a type parameter in a union type
+        topLevel: boolean;  // True if all inferences were made from top-level (not nested in object type) locations
         isFixed: boolean;   // Whether the type parameter is fixed, as defined in section 4.12.2 of the TypeScript spec
                             // If a type parameter is fixed, no more inferences can be made for the type parameter
     }
 
     /* @internal */
     export interface InferenceContext {
-        typeParameters: TypeParameter[];    // Type parameters for which inferences are made
+        signature: Signature;               // Generic signature for which inferences are made
         inferUnionTypes: boolean;           // Infer union types for disjoint candidates (otherwise undefinedType)
         inferences: TypeInferences[];       // Inferences made for each type parameter
         inferredTypes: Type[];              // Inferred type for each type parameter
@@ -2598,6 +2713,7 @@ namespace ts {
         experimentalDecorators?: boolean;
         forceConsistentCasingInFileNames?: boolean;
         /*@internal*/help?: boolean;
+        importHelpers?: boolean;
         /*@internal*/init?: boolean;
         inlineSourceMap?: boolean;
         inlineSources?: boolean;
@@ -2735,6 +2851,7 @@ namespace ts {
         raw?: any;
         errors: Diagnostic[];
         wildcardDirectories?: MapLike<WatchDirectoryFlags>;
+        compileOnSave?: boolean;
     }
 
     export const enum WatchDirectoryFlags {
@@ -2766,7 +2883,7 @@ namespace ts {
 
     /* @internal */
     export interface CommandLineOptionOfCustomType extends CommandLineOptionBase {
-        type: Map<number | string>;             // an object literal mapping named values to actual values
+        type: Map<number | string>;  // an object literal mapping named values to actual values
     }
 
     /* @internal */
@@ -2985,8 +3102,135 @@ namespace ts {
          * This method is a companion for 'resolveModuleNames' and is used to resolve 'types' references to actual type declaration files
          */
         resolveTypeReferenceDirectives?(typeReferenceDirectiveNames: string[], containingFile: string): ResolvedTypeReferenceDirective[];
+        getEnvironmentVariable?(name: string): string;
     }
 
+    /* @internal */
+    export const enum TransformFlags {
+        None = 0,
+
+        // Facts
+        // - Flags used to indicate that a node or subtree contains syntax that requires transformation.
+        TypeScript = 1 << 0,
+        ContainsTypeScript = 1 << 1,
+        Jsx = 1 << 2,
+        ContainsJsx = 1 << 3,
+        ES7 = 1 << 4,
+        ContainsES7 = 1 << 5,
+        ES6 = 1 << 6,
+        ContainsES6 = 1 << 7,
+        DestructuringAssignment = 1 << 8,
+        Generator = 1 << 9,
+        ContainsGenerator = 1 << 10,
+
+        // Markers
+        // - Flags used to indicate that a subtree contains a specific transformation.
+        ContainsDecorators = 1 << 11,
+        ContainsPropertyInitializer = 1 << 12,
+        ContainsLexicalThis = 1 << 13,
+        ContainsCapturedLexicalThis = 1 << 14,
+        ContainsLexicalThisInComputedPropertyName = 1 << 15,
+        ContainsDefaultValueAssignments = 1 << 16,
+        ContainsParameterPropertyAssignments = 1 << 17,
+        ContainsSpreadElementExpression = 1 << 18,
+        ContainsComputedPropertyName = 1 << 19,
+        ContainsBlockScopedBinding = 1 << 20,
+        ContainsBindingPattern = 1 << 21,
+        ContainsYield = 1 << 22,
+        ContainsHoistedDeclarationOrCompletion = 1 << 23,
+
+        HasComputedFlags = 1 << 29, // Transform flags have been computed.
+
+        // Assertions
+        // - Bitmasks that are used to assert facts about the syntax of a node and its subtree.
+        AssertTypeScript = TypeScript | ContainsTypeScript,
+        AssertJsx = Jsx | ContainsJsx,
+        AssertES7 = ES7 | ContainsES7,
+        AssertES6 = ES6 | ContainsES6,
+        AssertGenerator = Generator | ContainsGenerator,
+
+        // Scope Exclusions
+        // - Bitmasks that exclude flags from propagating out of a specific context
+        //   into the subtree flags of their container.
+        NodeExcludes = TypeScript | Jsx | ES7 | ES6 | DestructuringAssignment | Generator | HasComputedFlags,
+        ArrowFunctionExcludes = NodeExcludes | ContainsDecorators | ContainsDefaultValueAssignments | ContainsLexicalThis | ContainsParameterPropertyAssignments | ContainsBlockScopedBinding | ContainsYield | ContainsHoistedDeclarationOrCompletion,
+        FunctionExcludes = NodeExcludes | ContainsDecorators | ContainsDefaultValueAssignments | ContainsCapturedLexicalThis | ContainsLexicalThis | ContainsParameterPropertyAssignments | ContainsBlockScopedBinding | ContainsYield | ContainsHoistedDeclarationOrCompletion,
+        ConstructorExcludes = NodeExcludes | ContainsDefaultValueAssignments | ContainsLexicalThis | ContainsCapturedLexicalThis | ContainsBlockScopedBinding | ContainsYield | ContainsHoistedDeclarationOrCompletion,
+        MethodOrAccessorExcludes = NodeExcludes | ContainsDefaultValueAssignments | ContainsLexicalThis | ContainsCapturedLexicalThis | ContainsBlockScopedBinding | ContainsYield | ContainsHoistedDeclarationOrCompletion,
+        ClassExcludes = NodeExcludes | ContainsDecorators | ContainsPropertyInitializer | ContainsLexicalThis | ContainsCapturedLexicalThis | ContainsComputedPropertyName | ContainsParameterPropertyAssignments | ContainsLexicalThisInComputedPropertyName,
+        ModuleExcludes = NodeExcludes | ContainsDecorators | ContainsLexicalThis | ContainsCapturedLexicalThis | ContainsBlockScopedBinding | ContainsHoistedDeclarationOrCompletion,
+        TypeExcludes = ~ContainsTypeScript,
+        ObjectLiteralExcludes = NodeExcludes | ContainsDecorators | ContainsComputedPropertyName | ContainsLexicalThisInComputedPropertyName,
+        ArrayLiteralOrCallOrNewExcludes = NodeExcludes | ContainsSpreadElementExpression,
+        VariableDeclarationListExcludes = NodeExcludes | ContainsBindingPattern,
+        ParameterExcludes = NodeExcludes | ContainsBindingPattern,
+
+        // Masks
+        // - Additional bitmasks
+        TypeScriptClassSyntaxMask = ContainsParameterPropertyAssignments | ContainsPropertyInitializer | ContainsDecorators,
+        ES6FunctionSyntaxMask = ContainsCapturedLexicalThis | ContainsDefaultValueAssignments,
+    }
+
+    /* @internal */
+    export interface EmitNode {
+        flags?: EmitFlags;
+        commentRange?: TextRange;
+        sourceMapRange?: TextRange;
+        tokenSourceMapRanges?: Map<TextRange>;
+        annotatedNodes?: Node[];                // Tracks Parse-tree nodes with EmitNodes for eventual cleanup.
+        constantValue?: number;
+    }
+
+    /* @internal */
+    export const enum EmitFlags {
+        EmitEmitHelpers = 1 << 0,                // Any emit helpers should be written to this node.
+        EmitExportStar = 1 << 1,                 // The export * helper should be written to this node.
+        EmitSuperHelper = 1 << 2,                // Emit the basic _super helper for async methods.
+        EmitAdvancedSuperHelper = 1 << 3,        // Emit the advanced _super helper for async methods.
+        UMDDefine = 1 << 4,                      // This node should be replaced with the UMD define helper.
+        SingleLine = 1 << 5,                     // The contents of this node should be emitted on a single line.
+        AdviseOnEmitNode = 1 << 6,               // The printer should invoke the onEmitNode callback when printing this node.
+        NoSubstitution = 1 << 7,                 // Disables further substitution of an expression.
+        CapturesThis = 1 << 8,                   // The function captures a lexical `this`
+        NoLeadingSourceMap = 1 << 9,             // Do not emit a leading source map location for this node.
+        NoTrailingSourceMap = 1 << 10,           // Do not emit a trailing source map location for this node.
+        NoSourceMap = NoLeadingSourceMap | NoTrailingSourceMap, // Do not emit a source map location for this node.
+        NoNestedSourceMaps = 1 << 11,            // Do not emit source map locations for children of this node.
+        NoTokenLeadingSourceMaps = 1 << 12,      // Do not emit leading source map location for token nodes.
+        NoTokenTrailingSourceMaps = 1 << 13,     // Do not emit trailing source map location for token nodes.
+        NoTokenSourceMaps = NoTokenLeadingSourceMaps | NoTokenTrailingSourceMaps, // Do not emit source map locations for tokens of this node.
+        NoLeadingComments = 1 << 14,             // Do not emit leading comments for this node.
+        NoTrailingComments = 1 << 15,            // Do not emit trailing comments for this node.
+        NoComments = NoLeadingComments | NoTrailingComments, // Do not emit comments for this node.
+        NoNestedComments = 1 << 16,
+        ExportName = 1 << 17,                    // Ensure an export prefix is added for an identifier that points to an exported declaration with a local name (see SymbolFlags.ExportHasLocal).
+        LocalName = 1 << 18,                     // Ensure an export prefix is not added for an identifier that points to an exported declaration.
+        Indented = 1 << 19,                      // Adds an explicit extra indentation level for class and function bodies when printing (used to match old emitter).
+        NoIndentation = 1 << 20,                 // Do not indent the node.
+        AsyncFunctionBody = 1 << 21,
+        ReuseTempVariableScope = 1 << 22,        // Reuse the existing temp variable scope during emit.
+        CustomPrologue = 1 << 23,                // Treat the statement as if it were a prologue directive (NOTE: Prologue directives are *not* transformed).
+    }
+
+    /* @internal */
+    export const enum EmitContext {
+        SourceFile,         // Emitting a SourceFile
+        Expression,         // Emitting an Expression
+        IdentifierName,     // Emitting an IdentifierName
+        Unspecified,        // Emitting an otherwise unspecified node
+    }
+
+    /** Additional context provided to `visitEachChild` */
+    /* @internal */
+    export interface LexicalEnvironment {
+        /** Starts a new lexical environment. */
+        startLexicalEnvironment(): void;
+
+        /** Ends a lexical environment, returning any declarations. */
+        endLexicalEnvironment(): Statement[];
+    }
+
+
     export interface TextSpan {
         start: number;
         length: number;

src/harness/compilerRunner.ts

@@ -1,8 +1,6 @@
 /// <reference path="harness.ts" />
 /// <reference path="runnerbase.ts" />
 /// <reference path="typeWriter.ts" />
-// In harness baselines, null is different than undefined. See `generateActual` in `harness.ts`.
-/* tslint:disable:no-null-keyword */
 
 const enum CompilerTestType {
     Conformance,
@@ -136,27 +134,14 @@ class CompilerBaselineRunner extends RunnerBase {
                 otherFiles = undefined;
             });
 
-            function getByteOrderMarkText(file: Harness.Compiler.GeneratedFile): string {
-                return file.writeByteOrderMark ? "\u00EF\u00BB\u00BF" : "";
-            }
-
-            function getErrorBaseline(toBeCompiled: Harness.Compiler.TestFile[], otherFiles: Harness.Compiler.TestFile[], result: Harness.Compiler.CompilerResult) {
-                return Harness.Compiler.getErrorBaseline(toBeCompiled.concat(otherFiles), result.errors);
-            }
-
             // check errors
             it("Correct errors for " + fileName, () => {
-                if (this.errors) {
-                    Harness.Baseline.runBaseline("Correct errors for " + fileName, justName.replace(/\.tsx?$/, ".errors.txt"), (): string => {
-                        if (result.errors.length === 0) return null;
-                        return getErrorBaseline(toBeCompiled, otherFiles, result);
-                    });
-                }
+                 Harness.Compiler.doErrorBaseline(justName, toBeCompiled.concat(otherFiles), result.errors);
             });
 
             it (`Correct module resolution tracing for ${fileName}`, () => {
                 if (options.traceResolution) {
-                    Harness.Baseline.runBaseline("Correct module resolution tracing for " + fileName, justName.replace(/\.tsx?$/, ".trace.json"), () => {
+                    Harness.Baseline.runBaseline(justName.replace(/\.tsx?$/, ".trace.json"), () => {
                         return JSON.stringify(result.traceResults || [], undefined, 4);
                     });
                 }
@@ -165,11 +150,13 @@ class CompilerBaselineRunner extends RunnerBase {
             // Source maps?
             it("Correct sourcemap content for " + fileName, () => {
                 if (options.sourceMap || options.inlineSourceMap) {
-                    Harness.Baseline.runBaseline("Correct sourcemap content for " + fileName, justName.replace(/\.tsx?$/, ".sourcemap.txt"), () => {
+                    Harness.Baseline.runBaseline(justName.replace(/\.tsx?$/, ".sourcemap.txt"), () => {
                         const record = result.getSourceMapRecord();
-                        if (options.noEmitOnError && result.errors.length !== 0 && record === undefined) {
-                            // Because of the noEmitOnError option no files are created. We need to return null because baselining isn"t required.
+                        if ((options.noEmitOnError && result.errors.length !== 0) || record === undefined) {
+                            // Because of the noEmitOnError option no files are created. We need to return null because baselining isn't required.
+                            /* tslint:disable:no-null-keyword */
                             return null;
+                            /* tslint:enable:no-null-keyword */
                         }
                         return record;
                     });
@@ -178,87 +165,12 @@ class CompilerBaselineRunner extends RunnerBase {
 
             it("Correct JS output for " + fileName, () => {
                 if (hasNonDtsFiles && this.emit) {
-                    if (!options.noEmit && result.files.length === 0 && result.errors.length === 0) {
-                        throw new Error("Expected at least one js file to be emitted or at least one error to be created.");
-                    }
-
-                    // check js output
-                    Harness.Baseline.runBaseline("Correct JS output for " + fileName, justName.replace(/\.tsx?/, ".js"), () => {
-                        let tsCode = "";
-                        const tsSources = otherFiles.concat(toBeCompiled);
-                        if (tsSources.length > 1) {
-                            tsCode += "//// [" + fileName + "] ////\r\n\r\n";
-                        }
-                        for (let i = 0; i < tsSources.length; i++) {
-                            tsCode += "//// [" + Harness.Path.getFileName(tsSources[i].unitName) + "]\r\n";
-                            tsCode += tsSources[i].content + (i < (tsSources.length - 1) ? "\r\n" : "");
-                        }
-
-                        let jsCode = "";
-                        for (let i = 0; i < result.files.length; i++) {
-                            jsCode += "//// [" + Harness.Path.getFileName(result.files[i].fileName) + "]\r\n";
-                            jsCode += getByteOrderMarkText(result.files[i]);
-                            jsCode += result.files[i].code;
-                        }
-
-                        if (result.declFilesCode.length > 0) {
-                            jsCode += "\r\n\r\n";
-                            for (let i = 0; i < result.declFilesCode.length; i++) {
-                                jsCode += "//// [" + Harness.Path.getFileName(result.declFilesCode[i].fileName) + "]\r\n";
-                                jsCode += getByteOrderMarkText(result.declFilesCode[i]);
-                                jsCode += result.declFilesCode[i].code;
-                            }
-                        }
-
-                        const declFileCompilationResult =
-                            Harness.Compiler.compileDeclarationFiles(
-                                toBeCompiled, otherFiles, result, harnessSettings, options, /*currentDirectory*/ undefined);
-
-                        if (declFileCompilationResult && declFileCompilationResult.declResult.errors.length) {
-                            jsCode += "\r\n\r\n//// [DtsFileErrors]\r\n";
-                            jsCode += "\r\n\r\n";
-                            jsCode += getErrorBaseline(declFileCompilationResult.declInputFiles, declFileCompilationResult.declOtherFiles, declFileCompilationResult.declResult);
-                        }
-
-                        if (jsCode.length > 0) {
-                            return tsCode + "\r\n\r\n" + jsCode;
-                        }
-                        else {
-                            return null;
-                        }
-                    });
+                    Harness.Compiler.doJsEmitBaseline(justName, fileName, options, result, toBeCompiled, otherFiles, harnessSettings);
                 }
             });
 
             it("Correct Sourcemap output for " + fileName, () => {
-                if (options.inlineSourceMap) {
-                    if (result.sourceMaps.length > 0) {
-                        throw new Error("No sourcemap files should be generated if inlineSourceMaps was set.");
-                    }
-                    return null;
-                }
-                else if (options.sourceMap) {
-                    if (result.sourceMaps.length !== result.files.length) {
-                        throw new Error("Number of sourcemap files should be same as js files.");
-                    }
-
-                    Harness.Baseline.runBaseline("Correct Sourcemap output for " + fileName, justName.replace(/\.tsx?/, ".js.map"), () => {
-                        if (options.noEmitOnError && result.errors.length !== 0 && result.sourceMaps.length === 0) {
-                            // We need to return null here or the runBaseLine will actually create a empty file.
-                            // Baselining isn't required here because there is no output.
-                            return null;
-                        }
-
-                        let sourceMapCode = "";
-                        for (let i = 0; i < result.sourceMaps.length; i++) {
-                            sourceMapCode += "//// [" + Harness.Path.getFileName(result.sourceMaps[i].fileName) + "]\r\n";
-                            sourceMapCode += getByteOrderMarkText(result.sourceMaps[i]);
-                            sourceMapCode += result.sourceMaps[i].code;
-                        }
-
-                        return sourceMapCode;
-                    });
-                }
+                Harness.Compiler.doSourcemapBaseline(justName, options, result);
             });
 
             it("Correct type/symbol baselines for " + fileName, () => {
@@ -266,129 +178,7 @@ class CompilerBaselineRunner extends RunnerBase {
                     return;
                 }
 
-                // NEWTODO: Type baselines
-                if (result.errors.length !== 0) {
-                    return;
-                }
-
-                // The full walker simulates the types that you would get from doing a full
-                // compile.  The pull walker simulates the types you get when you just do
-                // a type query for a random node (like how the LS would do it).  Most of the
-                // time, these will be the same.  However, occasionally, they can be different.
-                // Specifically, when the compiler internally depends on symbol IDs to order
-                // things, then we may see different results because symbols can be created in a
-                // different order with 'pull' operations, and thus can produce slightly differing
-                // output.
-                //
-                // For example, with a full type check, we may see a type displayed as: number | string
-                // But with a pull type check, we may see it as:                        string | number
-                //
-                // These types are equivalent, but depend on what order the compiler observed
-                // certain parts of the program.
-
-                const program = result.program;
-                const allFiles = toBeCompiled.concat(otherFiles).filter(file => !!program.getSourceFile(file.unitName));
-
-                const fullWalker = new TypeWriterWalker(program, /*fullTypeCheck*/ true);
-
-                const fullResults = ts.createMap<TypeWriterResult[]>();
-                const pullResults = ts.createMap<TypeWriterResult[]>();
-
-                for (const sourceFile of allFiles) {
-                    fullResults[sourceFile.unitName] = fullWalker.getTypeAndSymbols(sourceFile.unitName);
-                    pullResults[sourceFile.unitName] = fullWalker.getTypeAndSymbols(sourceFile.unitName);
-                }
-
-                // Produce baselines.  The first gives the types for all expressions.
-                // The second gives symbols for all identifiers.
-                let e1: Error, e2: Error;
-                try {
-                    checkBaseLines(/*isSymbolBaseLine*/ false);
-                }
-                catch (e) {
-                    e1 = e;
-                }
-
-                try {
-                    checkBaseLines(/*isSymbolBaseLine*/ true);
-                }
-                catch (e) {
-                    e2 = e;
-                }
-
-                if (e1 || e2) {
-                    throw e1 || e2;
-                }
-
-                return;
-
-                function checkBaseLines(isSymbolBaseLine: boolean) {
-                    const fullBaseLine = generateBaseLine(fullResults, isSymbolBaseLine);
-                    const pullBaseLine = generateBaseLine(pullResults, isSymbolBaseLine);
-
-                    const fullExtension = isSymbolBaseLine ? ".symbols" : ".types";
-                    const pullExtension = isSymbolBaseLine ? ".symbols.pull" : ".types.pull";
-
-                    if (fullBaseLine !== pullBaseLine) {
-                        Harness.Baseline.runBaseline("Correct full information for " + fileName, justName.replace(/\.tsx?/, fullExtension), () => fullBaseLine);
-                        Harness.Baseline.runBaseline("Correct pull information for " + fileName, justName.replace(/\.tsx?/, pullExtension), () => pullBaseLine);
-                    }
-                    else {
-                        Harness.Baseline.runBaseline("Correct information for " + fileName, justName.replace(/\.tsx?/, fullExtension), () => fullBaseLine);
-                    }
-                }
-
-                function generateBaseLine(typeWriterResults: ts.Map<TypeWriterResult[]>, isSymbolBaseline: boolean): string {
-                    const typeLines: string[] = [];
-                    const typeMap: { [fileName: string]: { [lineNum: number]: string[]; } } = {};
-
-                    allFiles.forEach(file => {
-                        const codeLines = file.content.split("\n");
-                        typeWriterResults[file.unitName].forEach(result => {
-                            if (isSymbolBaseline && !result.symbol) {
-                                return;
-                            }
-
-                            const typeOrSymbolString = isSymbolBaseline ? result.symbol : result.type;
-                            const formattedLine = result.sourceText.replace(/\r?\n/g, "") + " : " + typeOrSymbolString;
-                            if (!typeMap[file.unitName]) {
-                                typeMap[file.unitName] = {};
-                            }
-
-                            let typeInfo = [formattedLine];
-                            const existingTypeInfo = typeMap[file.unitName][result.line];
-                            if (existingTypeInfo) {
-                                typeInfo = existingTypeInfo.concat(typeInfo);
-                            }
-                            typeMap[file.unitName][result.line] = typeInfo;
-                        });
-
-                        typeLines.push("=== " + file.unitName + " ===\r\n");
-                        for (let i = 0; i < codeLines.length; i++) {
-                            const currentCodeLine = codeLines[i];
-                            typeLines.push(currentCodeLine + "\r\n");
-                            if (typeMap[file.unitName]) {
-                                const typeInfo = typeMap[file.unitName][i];
-                                if (typeInfo) {
-                                    typeInfo.forEach(ty => {
-                                        typeLines.push(">" + ty + "\r\n");
-                                    });
-                                    if (i + 1 < codeLines.length && (codeLines[i + 1].match(/^\s*[{|}]\s*$/) || codeLines[i + 1].trim() === "")) {
-                                    }
-                                    else {
-                                        typeLines.push("\r\n");
-                                    }
-                                }
-                            }
-                            else {
-                                typeLines.push("No type information for this code.");
-                            }
-                        }
-                    });
-
-                    return typeLines.join("");
-                }
-
+                Harness.Compiler.doTypeAndSymbolBaseline(justName, result, toBeCompiled.concat(otherFiles).filter(file => !!result.program.getSourceFile(file.unitName)));
             });
         });
     }

src/harness/fourslash.ts

@@ -88,6 +88,10 @@ namespace FourSlash {
         marker?: Marker;
     }
 
+    interface ImplementationLocationInformation extends ts.ImplementationLocation {
+        matched?: boolean;
+    }
+
     export interface TextSpan {
         start: number;
         end: number;
@@ -202,10 +206,28 @@ namespace FourSlash {
         // Whether or not we should format on keystrokes
         public enableFormatting = true;
 
-        public formatCodeOptions: ts.FormatCodeOptions;
+        public formatCodeSettings: ts.FormatCodeSettings;
 
         private inputFiles = ts.createMap<string>();  // Map between inputFile's fileName and its content for easily looking up when resolving references
 
+        private static getDisplayPartsJson(displayParts: ts.SymbolDisplayPart[]) {
+            let result = "";
+            ts.forEach(displayParts, part => {
+                if (result) {
+                    result += ",\n    ";
+                }
+                else {
+                    result = "[\n    ";
+                }
+                result += JSON.stringify(part);
+            });
+            if (result) {
+                result += "\n]";
+            }
+
+            return result;
+        }
+
         // Add input file which has matched file name with the given reference-file path.
         // This is necessary when resolveReference flag is specified
         private addMatchedInputFile(referenceFilePath: string, extensions: string[]) {
@@ -245,22 +267,31 @@ namespace FourSlash {
         constructor(private basePath: string, private testType: FourSlashTestType, public testData: FourSlashData) {
             // Create a new Services Adapter
             this.cancellationToken = new TestCancellationToken();
-            const compilationOptions = convertGlobalOptionsToCompilerOptions(this.testData.globalOptions);
-            if (compilationOptions.typeRoots) {
-                compilationOptions.typeRoots = compilationOptions.typeRoots.map(p => ts.getNormalizedAbsolutePath(p, this.basePath));
-            }
+            let compilationOptions = convertGlobalOptionsToCompilerOptions(this.testData.globalOptions);
             compilationOptions.skipDefaultLibCheck = true;
 
-            const languageServiceAdapter = this.getLanguageServiceAdapter(testType, this.cancellationToken, compilationOptions);
-            this.languageServiceAdapterHost = languageServiceAdapter.getHost();
-            this.languageService = languageServiceAdapter.getLanguageService();
-
             // Initialize the language service with all the scripts
             let startResolveFileRef: FourSlashFile;
 
             ts.forEach(testData.files, file => {
                 // Create map between fileName and its content for easily looking up when resolveReference flag is specified
                 this.inputFiles[file.fileName] = file.content;
+
+                if (ts.getBaseFileName(file.fileName).toLowerCase() === "tsconfig.json") {
+                    const configJson = ts.parseConfigFileTextToJson(file.fileName, file.content);
+                    assert.isTrue(configJson.config !== undefined);
+
+                    // Extend our existing compiler options so that we can also support tsconfig only options
+                    if (configJson.config.compilerOptions) {
+                        const baseDirectory = ts.normalizePath(ts.getDirectoryPath(file.fileName));
+                        const tsConfig = ts.convertCompilerOptionsFromJson(configJson.config.compilerOptions, baseDirectory, file.fileName);
+
+                        if (!tsConfig.errors || !tsConfig.errors.length) {
+                            compilationOptions = ts.extend(compilationOptions, tsConfig.options);
+                        }
+                    }
+                }
+
                 if (!startResolveFileRef && file.fileOptions[metadataOptionNames.resolveReference] === "true") {
                     startResolveFileRef = file;
                 }
@@ -270,6 +301,15 @@ namespace FourSlash {
                 }
             });
 
+
+            if (compilationOptions.typeRoots) {
+                compilationOptions.typeRoots = compilationOptions.typeRoots.map(p => ts.getNormalizedAbsolutePath(p, this.basePath));
+            }
+
+            const languageServiceAdapter = this.getLanguageServiceAdapter(testType, this.cancellationToken, compilationOptions);
+            this.languageServiceAdapterHost = languageServiceAdapter.getHost();
+            this.languageService = languageServiceAdapter.getLanguageService();
+
             if (startResolveFileRef) {
                 // Add the entry-point file itself into the languageServiceShimHost
                 this.languageServiceAdapterHost.addScript(startResolveFileRef.fileName, startResolveFileRef.content, /*isRootFile*/ true);
@@ -310,24 +350,26 @@ namespace FourSlash {
                     Harness.Compiler.getDefaultLibrarySourceFile().text, /*isRootFile*/ false);
             }
 
-            this.formatCodeOptions = {
-                BaseIndentSize: 0,
-                IndentSize: 4,
-                TabSize: 4,
-                NewLineCharacter: Harness.IO.newLine(),
-                ConvertTabsToSpaces: true,
-                IndentStyle: ts.IndentStyle.Smart,
-                InsertSpaceAfterCommaDelimiter: true,
-                InsertSpaceAfterSemicolonInForStatements: true,
-                InsertSpaceBeforeAndAfterBinaryOperators: true,
-                InsertSpaceAfterKeywordsInControlFlowStatements: true,
-                InsertSpaceAfterFunctionKeywordForAnonymousFunctions: false,
-                InsertSpaceAfterOpeningAndBeforeClosingNonemptyParenthesis: false,
-                InsertSpaceAfterOpeningAndBeforeClosingNonemptyBrackets: false,
-                InsertSpaceAfterOpeningAndBeforeClosingTemplateStringBraces: false,
-                InsertSpaceAfterOpeningAndBeforeClosingJsxExpressionBraces: false,
-                PlaceOpenBraceOnNewLineForFunctions: false,
-                PlaceOpenBraceOnNewLineForControlBlocks: false,
+            this.formatCodeSettings = {
+                baseIndentSize: 0,
+                indentSize: 4,
+                tabSize: 4,
+                newLineCharacter: Harness.IO.newLine(),
+                convertTabsToSpaces: true,
+                indentStyle: ts.IndentStyle.Smart,
+                insertSpaceAfterCommaDelimiter: true,
+                insertSpaceAfterSemicolonInForStatements: true,
+                insertSpaceBeforeAndAfterBinaryOperators: true,
+                insertSpaceAfterKeywordsInControlFlowStatements: true,
+                insertSpaceAfterFunctionKeywordForAnonymousFunctions: false,
+                insertSpaceAfterOpeningAndBeforeClosingNonemptyParenthesis: false,
+                insertSpaceAfterOpeningAndBeforeClosingNonemptyBrackets: false,
+                insertSpaceAfterOpeningAndBeforeClosingNonemptyBraces: true,
+                insertSpaceAfterOpeningAndBeforeClosingTemplateStringBraces: false,
+                insertSpaceAfterOpeningAndBeforeClosingJsxExpressionBraces: false,
+                insertSpaceAfterTypeAssertion: false,
+                placeOpenBraceOnNewLineForFunctions: false,
+                placeOpenBraceOnNewLineForControlBlocks: false,
             };
 
             // Open the first file by default
@@ -507,6 +549,67 @@ namespace FourSlash {
             }
         }
 
+        public verifyGoToDefinitionIs(endMarker: string | string[]) {
+            this.verifyGoToDefinitionWorker(endMarker instanceof Array ? endMarker : [endMarker]);
+        }
+
+        public verifyGoToDefinition(arg0: any, endMarkerNames?: string | string[]) {
+            if (endMarkerNames) {
+                this.verifyGoToDefinitionPlain(arg0, endMarkerNames);
+            }
+            else if (arg0 instanceof Array) {
+                const pairs: [string | string[], string | string[]][] = arg0;
+                for (const [start, end] of pairs) {
+                    this.verifyGoToDefinitionPlain(start, end);
+                }
+            }
+            else {
+                const obj: { [startMarkerName: string]: string | string[] } = arg0;
+                for (const startMarkerName in obj) {
+                    if (ts.hasProperty(obj, startMarkerName)) {
+                        this.verifyGoToDefinitionPlain(startMarkerName, obj[startMarkerName]);
+                    }
+                }
+            }
+        }
+
+        private verifyGoToDefinitionPlain(startMarkerNames: string | string[], endMarkerNames: string | string[]) {
+            if (startMarkerNames instanceof Array) {
+                for (const start of startMarkerNames) {
+                    this.verifyGoToDefinitionSingle(start, endMarkerNames);
+                }
+            }
+            else {
+                this.verifyGoToDefinitionSingle(startMarkerNames, endMarkerNames);
+            }
+        }
+
+        public verifyGoToDefinitionForMarkers(markerNames: string[]) {
+            for (const markerName of markerNames) {
+                this.verifyGoToDefinitionSingle(`${markerName}Reference`, `${markerName}Definition`);
+            }
+        }
+
+        private verifyGoToDefinitionSingle(startMarkerName: string, endMarkerNames: string | string[]) {
+            this.goToMarker(startMarkerName);
+            this.verifyGoToDefinitionWorker(endMarkerNames instanceof Array ? endMarkerNames : [endMarkerNames]);
+        }
+
+        private verifyGoToDefinitionWorker(endMarkers: string[]) {
+            const definitions = this.languageService.getDefinitionAtPosition(this.activeFile.fileName, this.currentCaretPosition) || [];
+
+            if (endMarkers.length !== definitions.length) {
+                this.raiseError(`goToDefinitions failed - expected to find ${endMarkers.length} definitions but got ${definitions.length}`);
+            }
+
+            for (let i = 0; i < endMarkers.length; i++) {
+                const marker = this.getMarkerByName(endMarkers[i]), definition = definitions[i];
+                if (marker.fileName !== definition.fileName || marker.position !== definition.textSpan.start) {
+                    this.raiseError(`goToDefinition failed for definition ${i}: expected ${marker.fileName} at ${marker.position}, got ${definition.fileName} at ${definition.textSpan.start}`);
+                }
+            }
+        }
+
         public verifyGetEmitOutputForCurrentFile(expected: string): void {
             const emit = this.languageService.getEmitOutput(this.activeFile.fileName);
             if (emit.outputFiles.length !== 1) {
@@ -651,10 +754,10 @@ namespace FourSlash {
             }
         }
 
-        public verifyCompletionListContains(symbol: string, text?: string, documentation?: string, kind?: string) {
+        public verifyCompletionListContains(symbol: string, text?: string, documentation?: string, kind?: string, spanIndex?: number) {
             const completions = this.getCompletionListAtCaret();
             if (completions) {
-                this.assertItemInCompletionList(completions.entries, symbol, text, documentation, kind);
+                this.assertItemInCompletionList(completions.entries, symbol, text, documentation, kind, spanIndex);
             }
             else {
                 this.raiseError(`No completions at position '${this.currentCaretPosition}' when looking for '${symbol}'.`);
@@ -670,25 +773,32 @@ namespace FourSlash {
          * @param expectedText the text associated with the symbol
          * @param expectedDocumentation the documentation text associated with the symbol
          * @param expectedKind the kind of symbol (see ScriptElementKind)
+         * @param spanIndex the index of the range that the completion item's replacement text span should match
          */
-        public verifyCompletionListDoesNotContain(symbol: string, expectedText?: string, expectedDocumentation?: string, expectedKind?: string) {
+        public verifyCompletionListDoesNotContain(symbol: string, expectedText?: string, expectedDocumentation?: string, expectedKind?: string, spanIndex?: number) {
             const that = this;
+            let replacementSpan: ts.TextSpan;
+            if (spanIndex !== undefined) {
+                replacementSpan = this.getTextSpanForRangeAtIndex(spanIndex);
+            }
+
             function filterByTextOrDocumentation(entry: ts.CompletionEntry) {
                 const details = that.getCompletionEntryDetails(entry.name);
                 const documentation = ts.displayPartsToString(details.documentation);
                 const text = ts.displayPartsToString(details.displayParts);
-                if (expectedText && expectedDocumentation) {
-                    return (documentation === expectedDocumentation && text === expectedText) ? true : false;
+
+                // If any of the expected values are undefined, assume that users don't
+                // care about them.
+                if (replacementSpan && !TestState.textSpansEqual(replacementSpan, entry.replacementSpan)) {
+                    return false;
                 }
-                else if (expectedText && !expectedDocumentation) {
-                    return text === expectedText ? true : false;
+                else if (expectedText && text !== expectedText) {
+                    return false;
                 }
-                else if (expectedDocumentation && !expectedText) {
-                    return documentation === expectedDocumentation ? true : false;
+                else if (expectedDocumentation && documentation !== expectedDocumentation) {
+                    return false;
                 }
-                // Because expectedText and expectedDocumentation are undefined, we assume that
-                // users don"t care to compare them so we will treat that entry as if the entry has matching text and documentation
-                // and keep it in the list of filtered entry.
+
                 return true;
             }
 
@@ -712,6 +822,10 @@ namespace FourSlash {
                     if (expectedKind) {
                         error += "Expected kind: " + expectedKind + " to equal: " + filterCompletions[0].kind + ".";
                     }
+                    if (replacementSpan) {
+                        const spanText = filterCompletions[0].replacementSpan ? stringify(filterCompletions[0].replacementSpan) : undefined;
+                        error += "Expected replacement span: " + stringify(replacementSpan) + " to equal: " + spanText + ".";
+                    }
                     this.raiseError(error);
                 }
             }
@@ -777,6 +891,20 @@ namespace FourSlash {
             ts.forEachProperty(this.rangesByText(), ranges => this.verifyRangesReferenceEachOther(ranges));
         }
 
+        public verifyDisplayPartsOfReferencedSymbol(expected: ts.SymbolDisplayPart[]) {
+            const referencedSymbols = this.findReferencesAtCaret();
+
+            if (referencedSymbols.length === 0) {
+                this.raiseError("No referenced symbols found at current caret position");
+            }
+            else if (referencedSymbols.length > 1) {
+                this.raiseError("More than one referenced symbol found");
+            }
+
+            assert.equal(TestState.getDisplayPartsJson(referencedSymbols[0].definition.displayParts),
+                TestState.getDisplayPartsJson(expected), this.messageAtLastKnownMarker("referenced symbol definition display parts"));
+        }
+
         private verifyReferencesWorker(references: ts.ReferenceEntry[], fileName: string, start: number, end: number, isWriteAccess?: boolean, isDefinition?: boolean) {
             for (let i = 0; i < references.length; i++) {
                 const reference = references[i];
@@ -811,6 +939,10 @@ namespace FourSlash {
             return this.languageService.getReferencesAtPosition(this.activeFile.fileName, this.currentCaretPosition);
         }
 
+        private findReferencesAtCaret() {
+            return this.languageService.findReferences(this.activeFile.fileName, this.currentCaretPosition);
+        }
+
         public getSyntacticDiagnostics(expected: string) {
             const diagnostics = this.languageService.getSyntacticDiagnostics(this.activeFile.fileName);
             this.testDiagnostics(expected, diagnostics);
@@ -827,59 +959,47 @@ namespace FourSlash {
             assert.equal(actual, expected);
         }
 
-        public verifyQuickInfoString(negative: boolean, expectedText?: string, expectedDocumentation?: string) {
+        public verifyQuickInfoAt(markerName: string, expectedText: string, expectedDocumentation?: string) {
+            this.goToMarker(markerName);
+            this.verifyQuickInfoString(expectedText, expectedDocumentation);
+        }
+
+        public verifyQuickInfos(namesAndTexts: { [name: string]: string | [string, string] }) {
+            ts.forEachProperty(ts.createMap(namesAndTexts), (text, name) => {
+                if (text instanceof Array) {
+                    assert(text.length === 2);
+                    const [expectedText, expectedDocumentation] = text;
+                    this.verifyQuickInfoAt(name, expectedText, expectedDocumentation);
+                }
+                else {
+                    this.verifyQuickInfoAt(name, text);
+                }
+            });
+        }
+
+        public verifyQuickInfoString(expectedText: string, expectedDocumentation?: string) {
+            if (expectedDocumentation === "") {
+                throw new Error("Use 'undefined' instead");
+            }
+
             const actualQuickInfo = this.languageService.getQuickInfoAtPosition(this.activeFile.fileName, this.currentCaretPosition);
             const actualQuickInfoText = actualQuickInfo ? ts.displayPartsToString(actualQuickInfo.displayParts) : "";
             const actualQuickInfoDocumentation = actualQuickInfo ? ts.displayPartsToString(actualQuickInfo.documentation) : "";
 
-            if (negative) {
-                if (expectedText !== undefined) {
-                    assert.notEqual(actualQuickInfoText, expectedText, this.messageAtLastKnownMarker("quick info text"));
-                }
-                // TODO: should be '==='?
-                if (expectedDocumentation != undefined) {
-                    assert.notEqual(actualQuickInfoDocumentation, expectedDocumentation, this.messageAtLastKnownMarker("quick info doc comment"));
-                }
-            }
-            else {
-                if (expectedText !== undefined) {
-                    assert.equal(actualQuickInfoText, expectedText, this.messageAtLastKnownMarker("quick info text"));
-                }
-                // TODO: should be '==='?
-                if (expectedDocumentation != undefined) {
-                    assert.equal(actualQuickInfoDocumentation, expectedDocumentation, this.assertionMessageAtLastKnownMarker("quick info doc"));
-                }
-            }
+            assert.equal(actualQuickInfoText, expectedText, this.messageAtLastKnownMarker("quick info text"));
+            assert.equal(actualQuickInfoDocumentation, expectedDocumentation || "", this.assertionMessageAtLastKnownMarker("quick info doc"));
         }
 
         public verifyQuickInfoDisplayParts(kind: string, kindModifiers: string, textSpan: { start: number; length: number; },
             displayParts: ts.SymbolDisplayPart[],
             documentation: ts.SymbolDisplayPart[]) {
 
-            function getDisplayPartsJson(displayParts: ts.SymbolDisplayPart[]) {
-                let result = "";
-                ts.forEach(displayParts, part => {
-                    if (result) {
-                        result += ",\n    ";
-                    }
-                    else {
-                        result = "[\n    ";
-                    }
-                    result += JSON.stringify(part);
-                });
-                if (result) {
-                    result += "\n]";
-                }
-
-                return result;
-            }
-
             const actualQuickInfo = this.languageService.getQuickInfoAtPosition(this.activeFile.fileName, this.currentCaretPosition);
             assert.equal(actualQuickInfo.kind, kind, this.messageAtLastKnownMarker("QuickInfo kind"));
             assert.equal(actualQuickInfo.kindModifiers, kindModifiers, this.messageAtLastKnownMarker("QuickInfo kindModifiers"));
             assert.equal(JSON.stringify(actualQuickInfo.textSpan), JSON.stringify(textSpan), this.messageAtLastKnownMarker("QuickInfo textSpan"));
-            assert.equal(getDisplayPartsJson(actualQuickInfo.displayParts), getDisplayPartsJson(displayParts), this.messageAtLastKnownMarker("QuickInfo displayParts"));
-            assert.equal(getDisplayPartsJson(actualQuickInfo.documentation), getDisplayPartsJson(documentation), this.messageAtLastKnownMarker("QuickInfo documentation"));
+            assert.equal(TestState.getDisplayPartsJson(actualQuickInfo.displayParts), TestState.getDisplayPartsJson(displayParts), this.messageAtLastKnownMarker("QuickInfo displayParts"));
+            assert.equal(TestState.getDisplayPartsJson(actualQuickInfo.documentation), TestState.getDisplayPartsJson(documentation), this.messageAtLastKnownMarker("QuickInfo documentation"));
         }
 
         public verifyRenameLocations(findInStrings: boolean, findInComments: boolean, ranges?: Range[]) {
@@ -1132,12 +1252,10 @@ namespace FourSlash {
 
             }
             Harness.Baseline.runBaseline(
-                "Breakpoint Locations for " + this.activeFile.fileName,
                 baselineFile,
                 () => {
                     return this.baselineCurrentFileLocations(pos => this.getBreakpointStatementLocation(pos));
-                },
-                true /* run immediately */);
+                });
         }
 
         public baselineGetEmitOutput() {
@@ -1159,7 +1277,6 @@ namespace FourSlash {
             }
 
             Harness.Baseline.runBaseline(
-                "Generate getEmitOutput baseline : " + emitFiles.join(" "),
                 this.testData.globalOptions[metadataOptionNames.baselineFile],
                 () => {
                     let resultString = "";
@@ -1185,8 +1302,23 @@ namespace FourSlash {
                     });
 
                     return resultString;
-                },
-                true /* run immediately */);
+                });
+        }
+
+        public baselineQuickInfo() {
+            let baselineFile = this.testData.globalOptions[metadataOptionNames.baselineFile];
+            if (!baselineFile) {
+                baselineFile = ts.getBaseFileName(this.activeFile.fileName).replace(".ts", ".baseline");
+            }
+
+            Harness.Baseline.runBaseline(
+                baselineFile,
+                () => stringify(
+                    this.testData.markers.map(marker => ({
+                        marker,
+                        quickInfo: this.languageService.getQuickInfoAtPosition(marker.fileName, marker.position)
+                    }))
+                ));
         }
 
         public printBreakpointLocation(pos: number) {
@@ -1296,7 +1428,7 @@ namespace FourSlash {
 
                 // Handle post-keystroke formatting
                 if (this.enableFormatting) {
-                    const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, offset, ch, this.formatCodeOptions);
+                    const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, offset, ch, this.formatCodeSettings);
                     if (edits.length) {
                         offset += this.applyEdits(this.activeFile.fileName, edits, /*isFormattingEdit*/ true);
                         // this.checkPostEditInvariants();
@@ -1334,7 +1466,7 @@ namespace FourSlash {
 
                 // Handle post-keystroke formatting
                 if (this.enableFormatting) {
-                    const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, offset, ch, this.formatCodeOptions);
+                    const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, offset, ch, this.formatCodeSettings);
                     if (edits.length) {
                         offset += this.applyEdits(this.activeFile.fileName, edits, /*isFormattingEdit*/ true);
                     }
@@ -1382,7 +1514,7 @@ namespace FourSlash {
 
                 // Handle post-keystroke formatting
                 if (this.enableFormatting) {
-                    const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, offset, ch, this.formatCodeOptions);
+                    const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, offset, ch, this.formatCodeSettings);
                     if (edits.length) {
                         offset += this.applyEdits(this.activeFile.fileName, edits, /*isFormattingEdit*/ true);
                     }
@@ -1406,7 +1538,7 @@ namespace FourSlash {
 
             // Handle formatting
             if (this.enableFormatting) {
-                const edits = this.languageService.getFormattingEditsForRange(this.activeFile.fileName, start, offset, this.formatCodeOptions);
+                const edits = this.languageService.getFormattingEditsForRange(this.activeFile.fileName, start, offset, this.formatCodeSettings);
                 if (edits.length) {
                     offset += this.applyEdits(this.activeFile.fileName, edits, /*isFormattingEdit*/ true);
                 }
@@ -1479,30 +1611,30 @@ namespace FourSlash {
             return runningOffset;
         }
 
-        public copyFormatOptions(): ts.FormatCodeOptions {
-            return ts.clone(this.formatCodeOptions);
+        public copyFormatOptions(): ts.FormatCodeSettings {
+            return ts.clone(this.formatCodeSettings);
         }
 
-        public setFormatOptions(formatCodeOptions: ts.FormatCodeOptions): ts.FormatCodeOptions {
-            const oldFormatCodeOptions = this.formatCodeOptions;
-            this.formatCodeOptions = formatCodeOptions;
+        public setFormatOptions(formatCodeOptions: ts.FormatCodeOptions | ts.FormatCodeSettings): ts.FormatCodeSettings {
+            const oldFormatCodeOptions = this.formatCodeSettings;
+            this.formatCodeSettings = ts.toEditorSettings(formatCodeOptions);
             return oldFormatCodeOptions;
         }
 
         public formatDocument() {
-            const edits = this.languageService.getFormattingEditsForDocument(this.activeFile.fileName, this.formatCodeOptions);
+            const edits = this.languageService.getFormattingEditsForDocument(this.activeFile.fileName, this.formatCodeSettings);
             this.currentCaretPosition += this.applyEdits(this.activeFile.fileName, edits, /*isFormattingEdit*/ true);
             this.fixCaretPosition();
         }
 
         public formatSelection(start: number, end: number) {
-            const edits = this.languageService.getFormattingEditsForRange(this.activeFile.fileName, start, end, this.formatCodeOptions);
+            const edits = this.languageService.getFormattingEditsForRange(this.activeFile.fileName, start, end, this.formatCodeSettings);
             this.currentCaretPosition += this.applyEdits(this.activeFile.fileName, edits, /*isFormattingEdit*/ true);
             this.fixCaretPosition();
         }
 
         public formatOnType(pos: number, key: string) {
-            const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, pos, key, this.formatCodeOptions);
+            const edits = this.languageService.getFormattingEditsAfterKeystroke(this.activeFile.fileName, pos, key, this.formatCodeSettings);
             this.currentCaretPosition += this.applyEdits(this.activeFile.fileName, edits, /*isFormattingEdit*/ true);
             this.fixCaretPosition();
         }
@@ -1547,25 +1679,10 @@ namespace FourSlash {
             this.goToPosition(len);
         }
 
-        public goToDefinition(definitionIndex: number) {
-            const definitions = this.languageService.getDefinitionAtPosition(this.activeFile.fileName, this.currentCaretPosition);
-            if (!definitions || !definitions.length) {
-                this.raiseError("goToDefinition failed - expected to at least one definition location but got 0");
-            }
-
-            if (definitionIndex >= definitions.length) {
-                this.raiseError(`goToDefinition failed - definitionIndex value (${definitionIndex}) exceeds definition list size (${definitions.length})`);
-            }
-
-            const definition = definitions[definitionIndex];
-            this.openFile(definition.fileName);
-            this.currentCaretPosition = definition.textSpan.start;
-        }
-
         public goToTypeDefinition(definitionIndex: number) {
             const definitions = this.languageService.getTypeDefinitionAtPosition(this.activeFile.fileName, this.currentCaretPosition);
             if (!definitions || !definitions.length) {
-                this.raiseError("goToTypeDefinition failed - expected to at least one definition location but got 0");
+                this.raiseError("goToTypeDefinition failed - expected to find at least one definition location but got 0");
             }
 
             if (definitionIndex >= definitions.length) {
@@ -1577,28 +1694,6 @@ namespace FourSlash {
             this.currentCaretPosition = definition.textSpan.start;
         }
 
-        public verifyDefinitionLocationExists(negative: boolean) {
-            const definitions = this.languageService.getDefinitionAtPosition(this.activeFile.fileName, this.currentCaretPosition);
-
-            const foundDefinitions = definitions && definitions.length;
-
-            if (foundDefinitions && negative) {
-                this.raiseError(`goToDefinition - expected to 0 definition locations but got ${definitions.length}`);
-            }
-            else if (!foundDefinitions && !negative) {
-                this.raiseError("goToDefinition - expected to at least one definition location but got 0");
-            }
-        }
-
-        public verifyDefinitionsCount(negative: boolean, expectedCount: number) {
-            const assertFn = negative ? assert.notEqual : assert.equal;
-
-            const definitions = this.languageService.getDefinitionAtPosition(this.activeFile.fileName, this.currentCaretPosition);
-            const actualCount = definitions && definitions.length || 0;
-
-            assertFn(actualCount, expectedCount, this.messageAtLastKnownMarker("Definitions Count"));
-        }
-
         public verifyTypeDefinitionsCount(negative: boolean, expectedCount: number) {
             const assertFn = negative ? assert.notEqual : assert.equal;
 
@@ -1608,17 +1703,98 @@ namespace FourSlash {
             assertFn(actualCount, expectedCount, this.messageAtLastKnownMarker("Type definitions Count"));
         }
 
-        public verifyDefinitionsName(negative: boolean, expectedName: string, expectedContainerName: string) {
+        public verifyImplementationListIsEmpty(negative: boolean) {
+            const implementations = this.languageService.getImplementationAtPosition(this.activeFile.fileName, this.currentCaretPosition);
+
+            if (negative) {
+                assert.isTrue(implementations && implementations.length > 0, "Expected at least one implementation but got 0");
+            }
+            else {
+                assert.isUndefined(implementations, "Expected implementation list to be empty but implementations returned");
+            }
+        }
+
+        public verifyGoToDefinitionName(expectedName: string, expectedContainerName: string) {
             const definitions = this.languageService.getDefinitionAtPosition(this.activeFile.fileName, this.currentCaretPosition);
             const actualDefinitionName = definitions && definitions.length ? definitions[0].name : "";
             const actualDefinitionContainerName = definitions && definitions.length ? definitions[0].containerName : "";
-            if (negative) {
-                assert.notEqual(actualDefinitionName, expectedName, this.messageAtLastKnownMarker("Definition Info Name"));
-                assert.notEqual(actualDefinitionContainerName, expectedContainerName, this.messageAtLastKnownMarker("Definition Info Container Name"));
+            assert.equal(actualDefinitionName, expectedName, this.messageAtLastKnownMarker("Definition Info Name"));
+            assert.equal(actualDefinitionContainerName, expectedContainerName, this.messageAtLastKnownMarker("Definition Info Container Name"));
+        }
+
+        public goToImplementation() {
+            const implementations = this.languageService.getImplementationAtPosition(this.activeFile.fileName, this.currentCaretPosition);
+            if (!implementations || !implementations.length) {
+                this.raiseError("goToImplementation failed - expected to find at least one implementation location but got 0");
             }
-            else {
-                assert.equal(actualDefinitionName, expectedName, this.messageAtLastKnownMarker("Definition Info Name"));
-                assert.equal(actualDefinitionContainerName, expectedContainerName, this.messageAtLastKnownMarker("Definition Info Container Name"));
+            if (implementations.length > 1) {
+                this.raiseError(`goToImplementation failed - more than 1 implementation returned (${implementations.length})`);
+            }
+
+            const implementation = implementations[0];
+            this.openFile(implementation.fileName);
+            this.currentCaretPosition = implementation.textSpan.start;
+        }
+
+        public verifyRangesInImplementationList(markerName: string) {
+            this.goToMarker(markerName);
+            const implementations: ImplementationLocationInformation[] = this.languageService.getImplementationAtPosition(this.activeFile.fileName, this.currentCaretPosition);
+            if (!implementations || !implementations.length) {
+                this.raiseError("verifyRangesInImplementationList failed - expected to find at least one implementation location but got 0");
+            }
+
+            for (let i = 0; i < implementations.length; i++) {
+                for (let j = 0; j < implementations.length; j++) {
+                    if (i !== j && implementationsAreEqual(implementations[i], implementations[j])) {
+                        const { textSpan, fileName } = implementations[i];
+                        const end = textSpan.start + textSpan.length;
+                        this.raiseError(`Duplicate implementations returned for range (${textSpan.start}, ${end}) in ${fileName}`);
+                    }
+                }
+            }
+
+            const ranges = this.getRanges();
+
+            if (!ranges || !ranges.length) {
+                this.raiseError("verifyRangesInImplementationList failed - expected to find at least one range in test source");
+            }
+
+            const unsatisfiedRanges: Range[] = [];
+
+            for (const range of ranges) {
+                const length = range.end - range.start;
+                const matchingImpl = ts.find(implementations, impl =>
+                    range.fileName === impl.fileName && range.start === impl.textSpan.start && length === impl.textSpan.length);
+                if (matchingImpl) {
+                    matchingImpl.matched = true;
+                }
+                else {
+                    unsatisfiedRanges.push(range);
+                }
+            }
+
+            const unmatchedImplementations = implementations.filter(impl => !impl.matched);
+            if (unmatchedImplementations.length || unsatisfiedRanges.length) {
+                let error = "Not all ranges or implementations are satisfied";
+                if (unsatisfiedRanges.length) {
+                    error += "\nUnsatisfied ranges:";
+                    for (const range of unsatisfiedRanges) {
+                        error += `\n    (${range.start}, ${range.end}) in ${range.fileName}: ${this.rangeText(range)}`;
+                    }
+                }
+
+                if (unmatchedImplementations.length) {
+                    error += "\nUnmatched implementations:";
+                    for (const impl of unmatchedImplementations) {
+                        const end = impl.textSpan.start + impl.textSpan.length;
+                        error += `\n    (${impl.textSpan.start}, ${end}) in ${impl.fileName}: ${this.getFileContent(impl.fileName).slice(impl.textSpan.start, end)}`;
+                    }
+                }
+                this.raiseError(error);
+            }
+
+            function implementationsAreEqual(a: ImplementationLocationInformation, b: ImplementationLocationInformation) {
+                return a.fileName === b.fileName && TestState.textSpansEqual(a.textSpan, b.textSpan);
             }
         }
 
@@ -1627,6 +1803,10 @@ namespace FourSlash {
             return this.testData.markers.slice(0);
         }
 
+        public getMarkerNames(): string[] {
+            return Object.keys(this.testData.markerPositions);
+        }
+
         public getRanges(): Range[] {
             return this.testData.ranges;
         }
@@ -1635,8 +1815,7 @@ namespace FourSlash {
             const result = ts.createMap<Range[]>();
             for (const range of this.getRanges()) {
                 const text = this.rangeText(range);
-                const ranges = result[text] || (result[text] = []);
-                ranges.push(range);
+                ts.multiMapAdd(result, text, range);
             }
             return result;
         }
@@ -1656,11 +1835,9 @@ namespace FourSlash {
         }
 
         private getIndentation(fileName: string, position: number, indentStyle: ts.IndentStyle, baseIndentSize: number): number {
-
-            const formatOptions = ts.clone(this.formatCodeOptions);
-            formatOptions.IndentStyle = indentStyle;
-            formatOptions.BaseIndentSize = baseIndentSize;
-
+            const formatOptions = ts.clone(this.formatCodeSettings);
+            formatOptions.indentStyle = indentStyle;
+            formatOptions.baseIndentSize = baseIndentSize;
             return this.languageService.getIndentationAtPosition(fileName, position, formatOptions);
         }
 
@@ -1730,13 +1907,11 @@ namespace FourSlash {
 
         public baselineCurrentFileNameOrDottedNameSpans() {
             Harness.Baseline.runBaseline(
-                "Name OrDottedNameSpans for " + this.activeFile.fileName,
                 this.testData.globalOptions[metadataOptionNames.baselineFile],
                 () => {
                     return this.baselineCurrentFileLocations(pos =>
                         this.getNameOrDottedNameSpan(pos));
-                },
-                true /* run immediately */);
+                });
         }
 
         public printNameOrDottedNameSpans(pos: number) {
@@ -1952,11 +2127,12 @@ namespace FourSlash {
         }
 
         /*
-            Check number of navigationItems which match both searchValue and matchKind.
+            Check number of navigationItems which match both searchValue and matchKind,
+            if a filename is passed in, limit the results to that file.
             Report an error if expected value and actual value do not match.
         */
-        public verifyNavigationItemsCount(expected: number, searchValue: string, matchKind?: string) {
-            const items = this.languageService.getNavigateToItems(searchValue);
+        public verifyNavigationItemsCount(expected: number, searchValue: string, matchKind?: string, fileName?: string) {
+            const items = this.languageService.getNavigateToItems(searchValue, /*maxResultCount*/ undefined, fileName);
             let actual = 0;
             let item: ts.NavigateToItem;
 
@@ -2155,7 +2331,7 @@ namespace FourSlash {
             return text.substring(startPos, endPos);
         }
 
-        private assertItemInCompletionList(items: ts.CompletionEntry[], name: string, text?: string, documentation?: string, kind?: string) {
+        private assertItemInCompletionList(items: ts.CompletionEntry[], name: string, text?: string, documentation?: string, kind?: string, spanIndex?: number) {
             for (let i = 0; i < items.length; i++) {
                 const item = items[i];
                 if (item.name === name) {
@@ -2174,6 +2350,11 @@ namespace FourSlash {
                         assert.equal(item.kind, kind, this.assertionMessageAtLastKnownMarker("completion item kind for " + name));
                     }
 
+                    if (spanIndex !== undefined) {
+                        const span = this.getTextSpanForRangeAtIndex(spanIndex);
+                        assert.isTrue(TestState.textSpansEqual(span, item.replacementSpan), this.assertionMessageAtLastKnownMarker(stringify(span) + " does not equal " + stringify(item.replacementSpan) + " replacement span for " + name));
+                    }
+
                     return;
                 }
             }
@@ -2230,6 +2411,17 @@ namespace FourSlash {
             return `line ${(pos.line + 1)}, col ${pos.character}`;
         }
 
+        private getTextSpanForRangeAtIndex(index: number): ts.TextSpan {
+            const ranges = this.getRanges();
+            if (ranges && ranges.length > index) {
+                const range = ranges[index];
+                return { start: range.start, length: range.end - range.start };
+            }
+            else {
+                this.raiseError("Supplied span index: " + index + " does not exist in range list of size: " + (ranges ? 0 : ranges.length));
+            }
+        }
+
         public getMarkerByName(markerName: string) {
             const markerPos = this.testData.markerPositions[markerName];
             if (markerPos === undefined) {
@@ -2253,6 +2445,10 @@ namespace FourSlash {
         public resetCancelled(): void {
             this.cancellationToken.resetCancelled();
         }
+
+        private static textSpansEqual(a: ts.TextSpan, b: ts.TextSpan) {
+            return a && b && a.start === b.start && a.length === b.length;
+        }
     }
 
     export function runFourSlashTest(basePath: string, testType: FourSlashTestType, fileName: string) {
@@ -2261,12 +2457,16 @@ namespace FourSlash {
     }
 
     export function runFourSlashTestContent(basePath: string, testType: FourSlashTestType, content: string, fileName: string): void {
+        // Give file paths an absolute path for the virtual file system
+        const absoluteBasePath = ts.combinePaths(Harness.virtualFileSystemRoot, basePath);
+        const absoluteFileName = ts.combinePaths(Harness.virtualFileSystemRoot, fileName);
+
         // Parse out the files and their metadata
-        const testData = parseTestData(basePath, content, fileName);
-        const state = new TestState(basePath, testType, testData);
+        const testData = parseTestData(absoluteBasePath, content, absoluteFileName);
+        const state = new TestState(absoluteBasePath, testType, testData);
         const output = ts.transpileModule(content, { reportDiagnostics: true });
         if (output.diagnostics.length > 0) {
-            throw new Error(`Syntax error in ${basePath}: ${output.diagnostics[0].messageText}`);
+            throw new Error(`Syntax error in ${absoluteBasePath}: ${output.diagnostics[0].messageText}`);
         }
         runCode(output.outputText, state);
     }
@@ -2731,6 +2931,10 @@ namespace FourSlashInterface {
             return this.state.getMarkers();
         }
 
+        public markerNames(): string[] {
+            return this.state.getMarkerNames();
+        }
+
         public marker(name?: string): FourSlash.Marker {
             return this.state.getMarkerByName(name);
         }
@@ -2766,14 +2970,14 @@ namespace FourSlashInterface {
             this.state.goToEOF();
         }
 
-        public definition(definitionIndex = 0) {
-            this.state.goToDefinition(definitionIndex);
-        }
-
         public type(definitionIndex = 0) {
             this.state.goToTypeDefinition(definitionIndex);
         }
 
+        public implementation() {
+            this.state.goToImplementation();
+        }
+
         public position(position: number, fileIndex?: number): void;
         public position(position: number, fileName?: string): void;
         public position(position: number, fileNameOrIndex?: any): void {
@@ -2819,12 +3023,12 @@ namespace FourSlashInterface {
 
         // Verifies the completion list contains the specified symbol. The
         // completion list is brought up if necessary
-        public completionListContains(symbol: string, text?: string, documentation?: string, kind?: string) {
+        public completionListContains(symbol: string, text?: string, documentation?: string, kind?: string, spanIndex?: number) {
             if (this.negative) {
-                this.state.verifyCompletionListDoesNotContain(symbol, text, documentation, kind);
+                this.state.verifyCompletionListDoesNotContain(symbol, text, documentation, kind, spanIndex);
             }
             else {
-                this.state.verifyCompletionListContains(symbol, text, documentation, kind);
+                this.state.verifyCompletionListContains(symbol, text, documentation, kind, spanIndex);
             }
         }
 
@@ -2866,28 +3070,16 @@ namespace FourSlashInterface {
             this.state.verifyErrorExistsAfterMarker(markerName, !this.negative, /*after*/ false);
         }
 
-        public quickInfoIs(expectedText?: string, expectedDocumentation?: string) {
-            this.state.verifyQuickInfoString(this.negative, expectedText, expectedDocumentation);
-        }
-
         public quickInfoExists() {
             this.state.verifyQuickInfoExists(this.negative);
         }
 
-        public definitionCountIs(expectedCount: number) {
-            this.state.verifyDefinitionsCount(this.negative, expectedCount);
-        }
-
         public typeDefinitionCountIs(expectedCount: number) {
             this.state.verifyTypeDefinitionsCount(this.negative, expectedCount);
         }
 
-        public definitionLocationExists() {
-            this.state.verifyDefinitionLocationExists(this.negative);
-        }
-
-        public verifyDefinitionsName(name: string, containerName: string) {
-            this.state.verifyDefinitionsName(this.negative, name, containerName);
+        public implementationListIsEmpty() {
+            this.state.verifyImplementationListIsEmpty(this.negative);
         }
 
         public isValidBraceCompletionAtPosition(openingBrace: string) {
@@ -2900,6 +3092,18 @@ namespace FourSlashInterface {
             super(state);
         }
 
+        public quickInfoIs(expectedText: string, expectedDocumentation?: string) {
+            this.state.verifyQuickInfoString(expectedText, expectedDocumentation);
+        }
+
+        public quickInfoAt(markerName: string, expectedText?: string, expectedDocumentation?: string) {
+            this.state.verifyQuickInfoAt(markerName, expectedText, expectedDocumentation);
+        }
+
+        public quickInfos(namesAndTexts: { [name: string]: string }) {
+            this.state.verifyQuickInfos(namesAndTexts);
+        }
+
         public caretAtMarker(markerName?: string) {
             this.state.verifyCaretAtMarker(markerName);
         }
@@ -2933,6 +3137,25 @@ namespace FourSlashInterface {
             this.state.verifyCurrentFileContent(text);
         }
 
+        public goToDefinitionIs(endMarkers: string | string[]) {
+            this.state.verifyGoToDefinitionIs(endMarkers);
+        }
+
+        public goToDefinition(startMarkerName: string | string[], endMarkerName: string | string[]): void;
+        public goToDefinition(startsAndEnds: [string | string[], string | string[]][]): void;
+        public goToDefinition(startsAndEnds: { [startMarkerName: string]: string | string[] }): void;
+        public goToDefinition(arg0: any, endMarkerName?: string | string[]) {
+            this.state.verifyGoToDefinition(arg0, endMarkerName);
+        }
+
+        public goToDefinitionForMarkers(...markerNames: string[]) {
+            this.state.verifyGoToDefinitionForMarkers(markerNames);
+        }
+
+        public goToDefinitionName(name: string, containerName: string) {
+            this.state.verifyGoToDefinitionName(name, containerName);
+        }
+
         public verifyGetEmitOutputForCurrentFile(expected: string): void {
             this.state.verifyGetEmitOutputForCurrentFile(expected);
         }
@@ -2953,6 +3176,10 @@ namespace FourSlashInterface {
             this.state.verifyRangesReferenceEachOther(ranges);
         }
 
+        public findReferencesDefinitionDisplayPartsAtCaretAre(expected: ts.SymbolDisplayPart[]) {
+            this.state.verifyDisplayPartsOfReferencedSymbol(expected);
+        }
+
         public rangesWithSameTextReferenceEachOther() {
             this.state.verifyRangesWithSameTextReferenceEachOther();
         }
@@ -3005,6 +3232,10 @@ namespace FourSlashInterface {
             this.state.baselineGetEmitOutput();
         }
 
+        public baselineQuickInfo() {
+            this.state.baselineQuickInfo();
+        }
+
         public nameOrDottedNameSpanTextIs(text: string) {
             this.state.verifyCurrentNameOrDottedNameSpanText(text);
         }
@@ -3037,8 +3268,8 @@ namespace FourSlashInterface {
             this.state.verifyNavigationBar(json);
         }
 
-        public navigationItemsListCount(count: number, searchValue: string, matchKind?: string) {
-            this.state.verifyNavigationItemsCount(count, searchValue, matchKind);
+        public navigationItemsListCount(count: number, searchValue: string, matchKind?: string, fileName?: string) {
+            this.state.verifyNavigationItemsCount(count, searchValue, matchKind, fileName);
         }
 
         public navigationItemsListContains(
@@ -3119,6 +3350,10 @@ namespace FourSlashInterface {
         public ProjectInfo(expected: string[]) {
             this.state.verifyProjectInfo(expected);
         }
+
+        public allRangesAppearInImplementationList(markerName: string) {
+            this.state.verifyRangesInImplementationList(markerName);
+        }
     }
 
     export class Edit {
@@ -3248,7 +3483,7 @@ namespace FourSlashInterface {
             this.state.formatDocument();
         }
 
-        public copyFormatOptions(): ts.FormatCodeOptions {
+        public copyFormatOptions(): ts.FormatCodeSettings {
             return this.state.copyFormatOptions();
         }
 
@@ -3268,7 +3503,7 @@ namespace FourSlashInterface {
         public setOption(name: string, value: string): void;
         public setOption(name: string, value: boolean): void;
         public setOption(name: string, value: any): void {
-            this.state.formatCodeOptions[name] = value;
+            (<any>this.state.formatCodeSettings)[name] = value;
         }
     }
 

src/harness/harness.ts

@@ -374,7 +374,7 @@ namespace Utils {
         // call this on both nodes to ensure all propagated flags have been set (and thus can be
         // compared).
         assert.equal(ts.containsParseError(node1), ts.containsParseError(node2));
-        assert.equal(node1.flags, node2.flags, "node1.flags !== node2.flags");
+        assert.equal(node1.flags & ~ts.NodeFlags.ReachabilityAndEmitFlags, node2.flags & ~ts.NodeFlags.ReachabilityAndEmitFlags, "node1.flags !== node2.flags");
 
         ts.forEachChild(node1,
             child1 => {
@@ -416,6 +416,60 @@ namespace Utils {
 
         throw new Error("Could not find child in parent");
     }
+
+    const maxHarnessFrames = 1;
+
+    export function filterStack(error: Error, stackTraceLimit: number = Infinity) {
+        const stack = <string>(<any>error).stack;
+        if (stack) {
+            const lines = stack.split(/\r\n?|\n/g);
+            const filtered: string[] = [];
+            let frameCount = 0;
+            let harnessFrameCount = 0;
+            for (let line of lines) {
+                if (isStackFrame(line)) {
+                    if (frameCount >= stackTraceLimit
+                        || isMocha(line)
+                        || isNode(line)) {
+                        continue;
+                    }
+
+                    if (isHarness(line)) {
+                        if (harnessFrameCount >= maxHarnessFrames) {
+                            continue;
+                        }
+
+                        harnessFrameCount++;
+                    }
+
+                    line = line.replace(/\bfile:\/\/\/(.*?)(?=(:\d+)*($|\)))/, (_, path) => ts.sys.resolvePath(path));
+                    frameCount++;
+                }
+
+                filtered.push(line);
+            }
+
+            (<any>error).stack = filtered.join(Harness.IO.newLine());
+        }
+
+        return error;
+    }
+
+    function isStackFrame(line: string) {
+        return /^\s+at\s/.test(line);
+    }
+
+    function isMocha(line: string) {
+        return /[\\/](node_modules|components)[\\/]mocha(js)?[\\/]|[\\/]mocha\.js/.test(line);
+    }
+
+    function isNode(line: string) {
+        return /\((timers|events|node|module)\.js:/.test(line);
+    }
+
+    function isHarness(line: string) {
+        return /[\\/]src[\\/]harness[\\/]|[\\/]run\.js/.test(line);
+    }
 }
 
 namespace Harness.Path {
@@ -452,12 +506,17 @@ namespace Harness {
         getExecutingFilePath(): string;
         exit(exitCode?: number): void;
         readDirectory(path: string, extension?: string[], exclude?: string[], include?: string[]): string[];
+        tryEnableSourceMapsForHost?(): void;
+        getEnvironmentVariable?(name: string): string;
     }
     export var IO: IO;
 
     // harness always uses one kind of new line
     const harnessNewLine = "\r\n";
 
+    // Root for file paths that are stored in a virtual file system
+    export const virtualFileSystemRoot = "/";
+
     namespace IOImpl {
         declare class Enumerator {
             public atEnd(): boolean;
@@ -490,6 +549,7 @@ namespace Harness {
             export const directoryExists: typeof IO.directoryExists = fso.FolderExists;
             export const fileExists: typeof IO.fileExists = fso.FileExists;
             export const log: typeof IO.log = global.WScript && global.WScript.StdOut.WriteLine;
+            export const getEnvironmentVariable: typeof IO.getEnvironmentVariable = name => ts.sys.getEnvironmentVariable(name);
             export const readDirectory: typeof IO.readDirectory = (path, extension, exclude, include) => ts.sys.readDirectory(path, extension, exclude, include);
 
             export function createDirectory(path: string) {
@@ -559,7 +619,13 @@ namespace Harness {
             export const writeFile: typeof IO.writeFile = (path, content) => ts.sys.writeFile(path, content);
             export const fileExists: typeof IO.fileExists = fs.existsSync;
             export const log: typeof IO.log = s => console.log(s);
+            export const getEnvironmentVariable: typeof IO.getEnvironmentVariable = name => ts.sys.getEnvironmentVariable(name);
 
+            export function tryEnableSourceMapsForHost() {
+                if (ts.sys.tryEnableSourceMapsForHost) {
+                    ts.sys.tryEnableSourceMapsForHost();
+                }
+            }
             export const readDirectory: typeof IO.readDirectory = (path, extension, exclude, include) => ts.sys.readDirectory(path, extension, exclude, include);
 
             export function createDirectory(path: string) {
@@ -710,7 +776,16 @@ namespace Harness {
                 return dirPath;
             }
             export let directoryName: typeof IO.directoryName = Utils.memoize(directoryNameImpl);
-            export const resolvePath = (path: string) => directoryName(path);
+
+            export function resolvePath(path: string) {
+                const response = Http.getFileFromServerSync(serverRoot + path + "?resolve=true");
+                if (response.status === 200) {
+                    return response.responseText;
+                }
+                else {
+                    return undefined;
+                }
+            }
 
             export function fileExists(path: string): boolean {
                 const response = Http.getFileFromServerSync(serverRoot + path);
@@ -784,7 +859,9 @@ namespace Harness {
 namespace Harness {
     export const libFolder = "built/local/";
     const tcServicesFileName = ts.combinePaths(libFolder, Utils.getExecutionEnvironment() === Utils.ExecutionEnvironment.Browser ? "typescriptServicesInBrowserTest.js" : "typescriptServices.js");
-    export const tcServicesFile = IO.readFile(tcServicesFileName);
+    export const tcServicesFile = IO.readFile(tcServicesFileName) + (Utils.getExecutionEnvironment() !== Utils.ExecutionEnvironment.Browser
+        ? IO.newLine() + `//# sourceURL=${IO.resolvePath(tcServicesFileName)}`
+        : "");
 
     export interface SourceMapEmitterCallback {
         (emittedFile: string, emittedLine: number, emittedColumn: number, sourceFile: string, sourceLine: number, sourceColumn: number, sourceName: string): void;
@@ -1328,6 +1405,233 @@ namespace Harness {
                 Harness.IO.newLine() + Harness.IO.newLine() + outputLines.join("\r\n");
         }
 
+        export function doErrorBaseline(baselinePath: string, inputFiles: TestFile[], errors: ts.Diagnostic[]) {
+            Harness.Baseline.runBaseline(baselinePath.replace(/\.tsx?$/, ".errors.txt"), (): string => {
+                if (!errors || (errors.length === 0)) {
+                    /* tslint:disable:no-null-keyword */
+                    return null;
+                    /* tslint:enable:no-null-keyword */
+                }
+                return getErrorBaseline(inputFiles, errors);
+            });
+        }
+
+        export function doTypeAndSymbolBaseline(baselinePath: string, result: CompilerResult, allFiles: {unitName: string, content: string}[], opts?: Harness.Baseline.BaselineOptions) {
+            if (result.errors.length !== 0) {
+                return;
+            }
+            // The full walker simulates the types that you would get from doing a full
+            // compile.  The pull walker simulates the types you get when you just do
+            // a type query for a random node (like how the LS would do it).  Most of the
+            // time, these will be the same.  However, occasionally, they can be different.
+            // Specifically, when the compiler internally depends on symbol IDs to order
+            // things, then we may see different results because symbols can be created in a
+            // different order with 'pull' operations, and thus can produce slightly differing
+            // output.
+            //
+            // For example, with a full type check, we may see a type displayed as: number | string
+            // But with a pull type check, we may see it as:                        string | number
+            //
+            // These types are equivalent, but depend on what order the compiler observed
+            // certain parts of the program.
+
+            const program = result.program;
+
+            const fullWalker = new TypeWriterWalker(program, /*fullTypeCheck*/ true);
+
+            const fullResults = ts.createMap<TypeWriterResult[]>();
+
+            for (const sourceFile of allFiles) {
+                fullResults[sourceFile.unitName] = fullWalker.getTypeAndSymbols(sourceFile.unitName);
+            }
+
+            // Produce baselines.  The first gives the types for all expressions.
+            // The second gives symbols for all identifiers.
+            let typesError: Error, symbolsError: Error;
+            try {
+                checkBaseLines(/*isSymbolBaseLine*/ false);
+            }
+            catch (e) {
+                typesError = e;
+            }
+
+            try {
+                checkBaseLines(/*isSymbolBaseLine*/ true);
+            }
+            catch (e) {
+                symbolsError = e;
+            }
+
+            if (typesError && symbolsError) {
+                throw new Error(typesError.message + ts.sys.newLine + symbolsError.message);
+            }
+
+            if (typesError) {
+                throw typesError;
+            }
+
+            if (symbolsError) {
+                throw symbolsError;
+            }
+
+            return;
+
+            function checkBaseLines(isSymbolBaseLine: boolean) {
+                const fullBaseLine = generateBaseLine(fullResults, isSymbolBaseLine);
+
+                const fullExtension = isSymbolBaseLine ? ".symbols" : ".types";
+
+                // When calling this function from rwc-runner, the baselinePath will have no extension.
+                // As rwc test- file is stored in json which ".json" will get stripped off.
+                // When calling this function from compiler-runner, the baselinePath will then has either ".ts" or ".tsx" extension
+                const outputFileName = ts.endsWith(baselinePath, ".ts") || ts.endsWith(baselinePath, ".tsx") ?
+                    baselinePath.replace(/\.tsx?/, fullExtension) : baselinePath.concat(fullExtension);
+                Harness.Baseline.runBaseline(outputFileName, () => fullBaseLine, opts);
+            }
+
+            function generateBaseLine(typeWriterResults: ts.Map<TypeWriterResult[]>, isSymbolBaseline: boolean): string {
+                const typeLines: string[] = [];
+                const typeMap: { [fileName: string]: { [lineNum: number]: string[]; } } = {};
+
+                allFiles.forEach(file => {
+                    const codeLines = file.content.split("\n");
+                    typeWriterResults[file.unitName].forEach(result => {
+                        if (isSymbolBaseline && !result.symbol) {
+                            return;
+                        }
+
+                        const typeOrSymbolString = isSymbolBaseline ? result.symbol : result.type;
+                        const formattedLine = result.sourceText.replace(/\r?\n/g, "") + " : " + typeOrSymbolString;
+                        if (!typeMap[file.unitName]) {
+                            typeMap[file.unitName] = {};
+                        }
+
+                        let typeInfo = [formattedLine];
+                        const existingTypeInfo = typeMap[file.unitName][result.line];
+                        if (existingTypeInfo) {
+                            typeInfo = existingTypeInfo.concat(typeInfo);
+                        }
+                        typeMap[file.unitName][result.line] = typeInfo;
+                    });
+
+                    typeLines.push("=== " + file.unitName + " ===\r\n");
+                    for (let i = 0; i < codeLines.length; i++) {
+                        const currentCodeLine = codeLines[i];
+                        typeLines.push(currentCodeLine + "\r\n");
+                        if (typeMap[file.unitName]) {
+                            const typeInfo = typeMap[file.unitName][i];
+                            if (typeInfo) {
+                                typeInfo.forEach(ty => {
+                                    typeLines.push(">" + ty + "\r\n");
+                                });
+                                if (i + 1 < codeLines.length && (codeLines[i + 1].match(/^\s*[{|}]\s*$/) || codeLines[i + 1].trim() === "")) {
+                                }
+                                else {
+                                    typeLines.push("\r\n");
+                                }
+                            }
+                        }
+                        else {
+                            typeLines.push("No type information for this code.");
+                        }
+                    }
+                });
+
+                return typeLines.join("");
+            }
+        }
+
+        function getByteOrderMarkText(file: Harness.Compiler.GeneratedFile): string {
+            return file.writeByteOrderMark ? "\u00EF\u00BB\u00BF" : "";
+        }
+
+        export function doSourcemapBaseline(baselinePath: string, options: ts.CompilerOptions, result: CompilerResult) {
+            if (options.inlineSourceMap) {
+                if (result.sourceMaps.length > 0) {
+                    throw new Error("No sourcemap files should be generated if inlineSourceMaps was set.");
+                }
+                return;
+            }
+            else if (options.sourceMap) {
+                if (result.sourceMaps.length !== result.files.length) {
+                    throw new Error("Number of sourcemap files should be same as js files.");
+                }
+
+                Harness.Baseline.runBaseline(baselinePath.replace(/\.tsx?/, ".js.map"), () => {
+                    if ((options.noEmitOnError && result.errors.length !== 0) || result.sourceMaps.length === 0) {
+                        // We need to return null here or the runBaseLine will actually create a empty file.
+                        // Baselining isn't required here because there is no output.
+                        /* tslint:disable:no-null-keyword */
+                        return null;
+                        /* tslint:enable:no-null-keyword */
+                    }
+
+                    let sourceMapCode = "";
+                    for (let i = 0; i < result.sourceMaps.length; i++) {
+                        sourceMapCode += "//// [" + Harness.Path.getFileName(result.sourceMaps[i].fileName) + "]\r\n";
+                        sourceMapCode += getByteOrderMarkText(result.sourceMaps[i]);
+                        sourceMapCode += result.sourceMaps[i].code;
+                    }
+
+                    return sourceMapCode;
+                });
+            }
+        }
+
+        export function doJsEmitBaseline(baselinePath: string, header: string, options: ts.CompilerOptions, result: CompilerResult, toBeCompiled: Harness.Compiler.TestFile[], otherFiles: Harness.Compiler.TestFile[], harnessSettings: Harness.TestCaseParser.CompilerSettings) {
+            if (!options.noEmit && result.files.length === 0 && result.errors.length === 0) {
+                throw new Error("Expected at least one js file to be emitted or at least one error to be created.");
+            }
+
+            // check js output
+            Harness.Baseline.runBaseline(baselinePath.replace(/\.tsx?/, ".js"), () => {
+                let tsCode = "";
+                const tsSources = otherFiles.concat(toBeCompiled);
+                if (tsSources.length > 1) {
+                    tsCode += "//// [" + header + "] ////\r\n\r\n";
+                }
+                for (let i = 0; i < tsSources.length; i++) {
+                    tsCode += "//// [" + Harness.Path.getFileName(tsSources[i].unitName) + "]\r\n";
+                    tsCode += tsSources[i].content + (i < (tsSources.length - 1) ? "\r\n" : "");
+                }
+
+                let jsCode = "";
+                for (let i = 0; i < result.files.length; i++) {
+                    jsCode += "//// [" + Harness.Path.getFileName(result.files[i].fileName) + "]\r\n";
+                    jsCode += getByteOrderMarkText(result.files[i]);
+                    jsCode += result.files[i].code;
+                }
+
+                if (result.declFilesCode.length > 0) {
+                    jsCode += "\r\n\r\n";
+                    for (let i = 0; i < result.declFilesCode.length; i++) {
+                        jsCode += "//// [" + Harness.Path.getFileName(result.declFilesCode[i].fileName) + "]\r\n";
+                        jsCode += getByteOrderMarkText(result.declFilesCode[i]);
+                        jsCode += result.declFilesCode[i].code;
+                    }
+                }
+
+                const declFileCompilationResult =
+                    Harness.Compiler.compileDeclarationFiles(
+                        toBeCompiled, otherFiles, result, harnessSettings, options, /*currentDirectory*/ undefined);
+
+                if (declFileCompilationResult && declFileCompilationResult.declResult.errors.length) {
+                    jsCode += "\r\n\r\n//// [DtsFileErrors]\r\n";
+                    jsCode += "\r\n\r\n";
+                    jsCode += Harness.Compiler.getErrorBaseline(declFileCompilationResult.declInputFiles.concat(declFileCompilationResult.declOtherFiles), declFileCompilationResult.declResult.errors);
+                }
+
+                if (jsCode.length > 0) {
+                    return tsCode + "\r\n\r\n" + jsCode;
+                }
+                else {
+                    /* tslint:disable:no-null-keyword */
+                    return null;
+                    /* tslint:enable:no-null-keyword */
+                }
+            });
+        }
+
         export function collateOutputs(outputFiles: Harness.Compiler.GeneratedFile[]): string {
             // Collect, test, and sort the fileNames
             outputFiles.sort((a, b) => cleanName(a.fileName).localeCompare(cleanName(b.fileName)));
@@ -1421,7 +1725,7 @@ namespace Harness {
             }
 
             public getSourceMapRecord() {
-                if (this.sourceMapData) {
+                if (this.sourceMapData && this.sourceMapData.length > 0) {
                     return Harness.SourceMapRecorder.getSourceMapRecord(this.sourceMapData, this.program, this.files);
                 }
             }
@@ -1540,7 +1844,8 @@ namespace Harness {
             const parseConfigHost: ts.ParseConfigHost = {
                 useCaseSensitiveFileNames: false,
                 readDirectory: (name) => [],
-                fileExists: (name) => true
+                fileExists: (name) => true,
+                readFile: (name) => ts.forEach(testUnitData, data => data.name.toLowerCase() === name.toLowerCase() ? data.content : undefined)
             };
 
             // check if project has tsconfig.json in the list of files
@@ -1558,7 +1863,7 @@ namespace Harness {
                     tsConfig.options.configFilePath = data.name;
 
                     // delete entry from the list
-                    testUnitData.splice(i, 1);
+                    ts.orderedRemoveItemAt(testUnitData, i);
 
                     break;
                 }
@@ -1604,31 +1909,7 @@ namespace Harness {
         }
 
         const fileCache: { [idx: string]: boolean } = {};
-        function generateActual(actualFileName: string, generateContent: () => string): string {
-            // For now this is written using TypeScript, because sys is not available when running old test cases.
-            // But we need to move to sys once we have
-            // Creates the directory including its parent if not already present
-            function createDirectoryStructure(dirName: string) {
-                if (fileCache[dirName] || IO.directoryExists(dirName)) {
-                    fileCache[dirName] = true;
-                    return;
-                }
-
-                const parentDirectory = IO.directoryName(dirName);
-                if (parentDirectory != "") {
-                    createDirectoryStructure(parentDirectory);
-                }
-                IO.createDirectory(dirName);
-                fileCache[dirName] = true;
-            }
-
-            // Create folders if needed
-            createDirectoryStructure(Harness.IO.directoryName(actualFileName));
-
-            // Delete the actual file in case it fails
-            if (IO.fileExists(actualFileName)) {
-                IO.deleteFile(actualFileName);
-            }
+        function generateActual(generateContent: () => string): string {
 
             const actual = generateContent();
 
@@ -1663,42 +1944,49 @@ namespace Harness {
             return { expected, actual };
         }
 
-        function writeComparison(expected: string, actual: string, relativeFileName: string, actualFileName: string, descriptionForDescribe: string) {
+        function writeComparison(expected: string, actual: string, relativeFileName: string, actualFileName: string) {
+            // For now this is written using TypeScript, because sys is not available when running old test cases.
+            // But we need to move to sys once we have
+            // Creates the directory including its parent if not already present
+            function createDirectoryStructure(dirName: string) {
+                if (fileCache[dirName] || IO.directoryExists(dirName)) {
+                    fileCache[dirName] = true;
+                    return;
+                }
+
+                const parentDirectory = IO.directoryName(dirName);
+                if (parentDirectory != "") {
+                    createDirectoryStructure(parentDirectory);
+                }
+                IO.createDirectory(dirName);
+                fileCache[dirName] = true;
+            }
+
+            // Create folders if needed
+            createDirectoryStructure(Harness.IO.directoryName(actualFileName));
+
+            // Delete the actual file in case it fails
+            if (IO.fileExists(actualFileName)) {
+                IO.deleteFile(actualFileName);
+            }
+
             const encoded_actual = Utils.encodeString(actual);
             if (expected !== encoded_actual) {
                 if (actual === NoContent) {
-                    IO.writeFile(relativeFileName + ".delete", "");
+                    IO.writeFile(actualFileName + ".delete", "");
                 }
                 else {
-                    IO.writeFile(relativeFileName, actual);
+                    IO.writeFile(actualFileName, actual);
                 }
-                // Overwrite & issue error
-                const errMsg = "The baseline file " + relativeFileName + " has changed.";
-                throw new Error(errMsg);
+                throw new Error(`The baseline file ${relativeFileName} has changed.`);
             }
         }
 
-        export function runBaseline(
-            descriptionForDescribe: string,
-            relativeFileName: string,
-            generateContent: () => string,
-            runImmediately = false,
-            opts?: BaselineOptions): void {
-
-            let actual = <string>undefined;
+        export function runBaseline(relativeFileName: string, generateContent: () => string, opts?: BaselineOptions): void {
             const actualFileName = localPath(relativeFileName, opts && opts.Baselinefolder, opts && opts.Subfolder);
-
-            if (runImmediately) {
-                actual = generateActual(actualFileName, generateContent);
-                const comparison = compareToBaseline(actual, relativeFileName, opts);
-                writeComparison(comparison.expected, comparison.actual, relativeFileName, actualFileName, descriptionForDescribe);
-            }
-            else {
-                actual = generateActual(actualFileName, generateContent);
-
-                const comparison = compareToBaseline(actual, relativeFileName, opts);
-                writeComparison(comparison.expected, comparison.actual, relativeFileName, actualFileName, descriptionForDescribe);
-            }
+            const actual = generateActual(generateContent);
+            const comparison = compareToBaseline(actual, relativeFileName, opts);
+            writeComparison(comparison.expected, comparison.actual, relativeFileName, actualFileName);
         }
     }
 

src/harness/harnessLanguageService.ts

@@ -123,7 +123,7 @@ namespace Harness.LanguageService {
     }
 
     export class LanguageServiceAdapterHost {
-        protected fileNameToScript = ts.createMap<ScriptInfo>();
+        protected virtualFileSystem: Utils.VirtualFileSystem = new Utils.VirtualFileSystem(virtualFileSystemRoot, /*useCaseSensitiveFilenames*/false);
 
         constructor(protected cancellationToken = DefaultHostCancellationToken.Instance,
                     protected settings = ts.getDefaultCompilerOptions()) {
@@ -135,22 +135,24 @@ namespace Harness.LanguageService {
 
         public getFilenames(): string[] {
             const fileNames: string[] = [];
-            ts.forEachProperty(this.fileNameToScript, (scriptInfo) => {
+            for (const virtualEntry of this.virtualFileSystem.getAllFileEntries()){
+                const scriptInfo = virtualEntry.content;
                 if (scriptInfo.isRootFile) {
                     // only include root files here
                     // usually it means that we won't include lib.d.ts in the list of root files so it won't mess the computation of compilation root dir.
                     fileNames.push(scriptInfo.fileName);
                 }
-            });
+            }
             return fileNames;
         }
 
         public getScriptInfo(fileName: string): ScriptInfo {
-            return this.fileNameToScript[fileName];
+            const fileEntry = this.virtualFileSystem.traversePath(fileName);
+            return fileEntry && fileEntry.isFile() ? (<Utils.VirtualFile>fileEntry).content : undefined;
         }
 
         public addScript(fileName: string, content: string, isRootFile: boolean): void {
-            this.fileNameToScript[fileName] = new ScriptInfo(fileName, content, isRootFile);
+            this.virtualFileSystem.addFile(fileName, new ScriptInfo(fileName, content, isRootFile));
         }
 
         public editScript(fileName: string, start: number, end: number, newText: string) {
@@ -171,7 +173,7 @@ namespace Harness.LanguageService {
           * @param col 0 based index
           */
         public positionToLineAndCharacter(fileName: string, position: number): ts.LineAndCharacter {
-            const script: ScriptInfo = this.fileNameToScript[fileName];
+            const script: ScriptInfo = this.getScriptInfo(fileName);
             assert.isOk(script);
 
             return ts.computeLineAndCharacterOfPosition(script.getLineMap(), position);
@@ -182,8 +184,14 @@ namespace Harness.LanguageService {
     class NativeLanguageServiceHost extends LanguageServiceAdapterHost implements ts.LanguageServiceHost {
         getCompilationSettings() { return this.settings; }
         getCancellationToken() { return this.cancellationToken; }
-        getDirectories(path: string): string[] { return []; }
-        getCurrentDirectory(): string { return ""; }
+        getDirectories(path: string): string[] {
+            const dir = this.virtualFileSystem.traversePath(path);
+            if (dir && dir.isDirectory()) {
+                return ts.map((<Utils.VirtualDirectory>dir).getDirectories(), (d) => ts.combinePaths(path, d.name));
+            }
+            return [];
+        }
+        getCurrentDirectory(): string { return virtualFileSystemRoot; }
         getDefaultLibFileName(): string { return Harness.Compiler.defaultLibFileName; }
         getScriptFileNames(): string[] { return this.getFilenames(); }
         getScriptSnapshot(fileName: string): ts.IScriptSnapshot {
@@ -196,6 +204,25 @@ namespace Harness.LanguageService {
             return script ? script.version.toString() : undefined;
         }
 
+        fileExists(fileName: string): boolean {
+            const script = this.getScriptSnapshot(fileName);
+            return script !== undefined;
+        }
+        readDirectory(path: string, extensions?: string[], exclude?: string[], include?: string[]): string[] {
+            return ts.matchFiles(path, extensions, exclude, include,
+            /*useCaseSensitiveFileNames*/false,
+            this.getCurrentDirectory(),
+            (p) => this.virtualFileSystem.getAccessibleFileSystemEntries(p));
+        }
+        readFile(path: string, encoding?: string): string {
+            const snapshot = this.getScriptSnapshot(path);
+            return snapshot.getText(0, snapshot.getLength());
+        }
+        getTypeRootsVersion() {
+            return 0;
+        }
+
+
         log(s: string): void { }
         trace(s: string): void { }
         error(s: string): void { }
@@ -384,6 +411,9 @@ namespace Harness.LanguageService {
         getCompletionEntryDetails(fileName: string, position: number, entryName: string): ts.CompletionEntryDetails {
             return unwrapJSONCallResult(this.shim.getCompletionEntryDetails(fileName, position, entryName));
         }
+        getCompletionEntrySymbol(fileName: string, position: number, entryName: string): ts.Symbol {
+            throw new Error("getCompletionEntrySymbol not implemented across the shim layer.");
+        }
         getQuickInfoAtPosition(fileName: string, position: number): ts.QuickInfo {
             return unwrapJSONCallResult(this.shim.getQuickInfoAtPosition(fileName, position));
         }
@@ -408,6 +438,9 @@ namespace Harness.LanguageService {
         getTypeDefinitionAtPosition(fileName: string, position: number): ts.DefinitionInfo[] {
             return unwrapJSONCallResult(this.shim.getTypeDefinitionAtPosition(fileName, position));
         }
+        getImplementationAtPosition(fileName: string, position: number): ts.ImplementationLocation[] {
+            return unwrapJSONCallResult(this.shim.getImplementationAtPosition(fileName, position));
+        }
         getReferencesAtPosition(fileName: string, position: number): ts.ReferenceEntry[] {
             return unwrapJSONCallResult(this.shim.getReferencesAtPosition(fileName, position));
         }
@@ -462,6 +495,9 @@ namespace Harness.LanguageService {
         getNonBoundSourceFile(fileName: string): ts.SourceFile {
             throw new Error("SourceFile can not be marshaled across the shim layer.");
         }
+        getSourceFile(fileName: string): ts.SourceFile {
+            throw new Error("SourceFile can not be marshaled across the shim layer.");
+        }
         dispose(): void { this.shim.dispose({}); }
     }
 
@@ -572,7 +608,6 @@ namespace Harness.LanguageService {
             this.writeMessage(message);
         }
 
-
         readFile(fileName: string): string {
             if (fileName.indexOf(Harness.Compiler.defaultLibFileName) >= 0) {
                 fileName = Harness.Compiler.defaultLibFileName;
@@ -617,6 +652,10 @@ namespace Harness.LanguageService {
             return [];
         }
 
+        getEnvironmentVariable(name: string): string {
+            return ts.sys.getEnvironmentVariable(name);
+        }
+
         readDirectory(path: string, extension?: string[], exclude?: string[], include?: string[]): string[] {
             throw new Error("Not implemented Yet.");
         }
@@ -644,7 +683,11 @@ namespace Harness.LanguageService {
             return true;
         }
 
-        isVerbose() {
+        getLogFileName(): string {
+            return undefined;
+        }
+
+        hasLevel() {
             return false;
         }
 
@@ -666,6 +709,14 @@ namespace Harness.LanguageService {
         clearTimeout(timeoutId: any): void {
             clearTimeout(timeoutId);
         }
+
+        setImmediate(callback: (...args: any[]) => void, ms: number, ...args: any[]): any {
+            return setImmediate(callback, args);
+        }
+
+        clearImmediate(timeoutId: any): void {
+            clearImmediate(timeoutId);
+        }
     }
 
     export class ServerLanguageServiceAdapter implements LanguageServiceAdapter {
@@ -680,8 +731,12 @@ namespace Harness.LanguageService {
             // host to answer server queries about files on disk
             const serverHost = new SessionServerHost(clientHost);
             const server = new ts.server.Session(serverHost,
-                Buffer ? Buffer.byteLength : (string: string, encoding?: string) => string.length,
-                process.hrtime, serverHost);
+                { isCancellationRequested: () => false },
+                /*useOneInferredProject*/ false,
+                /*typingsInstaller*/ undefined,
+                Utils.byteLength,
+                process.hrtime, serverHost,
+                /*canUseEvents*/ true);
 
             // Fake the connection between the client and the server
             serverHost.writeMessage = client.onMessage.bind(client);

src/harness/loggedIO.ts

@@ -1,6 +1,8 @@
 /// <reference path="..\..\src\compiler\sys.ts" />
 /// <reference path="..\..\src\harness\harness.ts" />
+/// <reference path="..\..\src\harness\harnessLanguageService.ts" />
 /// <reference path="..\..\src\harness\runnerbase.ts" />
+/// <reference path="..\..\src\harness\typeWriter.ts" />
 
 interface FileInformation {
     contents: string;

src/harness/projectsRunner.ts

@@ -222,6 +222,7 @@ class ProjectRunner extends RunnerBase {
                     useCaseSensitiveFileNames: Harness.IO.useCaseSensitiveFileNames(),
                     fileExists,
                     readDirectory,
+                    readFile
                 };
                 const configParseResult = ts.parseJsonConfigFileContent(configObject, configParseHost, ts.getDirectoryPath(configFileName), compilerOptions);
                 if (configParseResult.errors.length > 0) {
@@ -292,6 +293,10 @@ class ProjectRunner extends RunnerBase {
                 return Harness.IO.fileExists(getFileNameInTheProjectTest(fileName));
             }
 
+            function readFile(fileName: string): string {
+                return Harness.IO.readFile(getFileNameInTheProjectTest(fileName));
+            }
+
             function getSourceFileText(fileName: string): string {
                 let text: string = undefined;
                 try {
@@ -459,7 +464,7 @@ class ProjectRunner extends RunnerBase {
                     });
 
                     it("Resolution information of (" + moduleNameToString(moduleKind) + "): " + testCaseFileName, () => {
-                        Harness.Baseline.runBaseline("Resolution information of (" + moduleNameToString(compilerResult.moduleKind) + "): " + testCaseFileName, getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".json", () => {
+                        Harness.Baseline.runBaseline(getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".json", () => {
                             return JSON.stringify(getCompilerResolutionInfo(), undefined, "    ");
                         });
                     });
@@ -467,13 +472,12 @@ class ProjectRunner extends RunnerBase {
 
                     it("Errors for (" + moduleNameToString(moduleKind) + "): " + testCaseFileName, () => {
                         if (compilerResult.errors.length) {
-                            Harness.Baseline.runBaseline("Errors for (" + moduleNameToString(compilerResult.moduleKind) + "): " + testCaseFileName, getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".errors.txt", () => {
+                            Harness.Baseline.runBaseline(getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".errors.txt", () => {
                                 return getErrorsBaseline(compilerResult);
                             });
                         }
                     });
 
-
                     it("Baseline of emitted result (" + moduleNameToString(moduleKind) + "): " + testCaseFileName, () => {
                         if (testCase.baselineCheck) {
                             const errs: Error[] = [];
@@ -481,7 +485,7 @@ class ProjectRunner extends RunnerBase {
                                 // There may be multiple files with different baselines. Run all and report at the end, else
                                 // it stops copying the remaining emitted files from 'local/projectOutput' to 'local/project'.
                                 try {
-                                    Harness.Baseline.runBaseline("Baseline of emitted result (" + moduleNameToString(compilerResult.moduleKind) + "): " + testCaseFileName, getBaselineFolder(compilerResult.moduleKind) + outputFile.fileName, () => {
+                                    Harness.Baseline.runBaseline(getBaselineFolder(compilerResult.moduleKind) + outputFile.fileName, () => {
                                         try {
                                             return Harness.IO.readFile(getProjectOutputFolder(outputFile.fileName, compilerResult.moduleKind));
                                         }
@@ -500,23 +504,21 @@ class ProjectRunner extends RunnerBase {
                         }
                     });
 
-
-                    it("SourceMapRecord for (" + moduleNameToString(moduleKind) + "): " + testCaseFileName, () => {
-                        if (compilerResult.sourceMapData) {
-                            Harness.Baseline.runBaseline("SourceMapRecord for (" + moduleNameToString(compilerResult.moduleKind) + "): " + testCaseFileName, getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".sourcemap.txt", () => {
-                                return Harness.SourceMapRecorder.getSourceMapRecord(compilerResult.sourceMapData, compilerResult.program,
-                                    ts.filter(compilerResult.outputFiles, outputFile => Harness.Compiler.isJS(outputFile.emittedFileName)));
-                            });
-                        }
-                    });
+                    // it("SourceMapRecord for (" + moduleNameToString(moduleKind) + "): " + testCaseFileName, () => {
+                    //     if (compilerResult.sourceMapData) {
+                    //         Harness.Baseline.runBaseline(getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".sourcemap.txt", () => {
+                    //             return Harness.SourceMapRecorder.getSourceMapRecord(compilerResult.sourceMapData, compilerResult.program,
+                    //                 ts.filter(compilerResult.outputFiles, outputFile => Harness.Compiler.isJS(outputFile.emittedFileName)));
+                    //         });
+                    //     }
+                    // });
 
                     // Verify that all the generated .d.ts files compile
-
                     it("Errors in generated Dts files for (" + moduleNameToString(moduleKind) + "): " + testCaseFileName, () => {
                         if (!compilerResult.errors.length && testCase.declaration) {
                             const dTsCompileResult = compileCompileDTsFiles(compilerResult);
                             if (dTsCompileResult && dTsCompileResult.errors.length) {
-                                Harness.Baseline.runBaseline("Errors in generated Dts files for (" + moduleNameToString(compilerResult.moduleKind) + "): " + testCaseFileName, getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".dts.errors.txt", () => {
+                                Harness.Baseline.runBaseline(getBaselineFolder(compilerResult.moduleKind) + testCaseJustName + ".dts.errors.txt", () => {
                                     return getErrorsBaseline(dTsCompileResult);
                                 });
                             }

src/harness/runner.ts

@@ -82,6 +82,7 @@ interface TestConfig {
     light?: boolean;
     taskConfigsFolder?: string;
     workerCount?: number;
+    stackTraceLimit?: number | "full";
     tasks?: TaskSet[];
     test?: string[];
     runUnitTests?: boolean;
@@ -116,6 +117,13 @@ if (testConfigContent !== "") {
         }
     }
 
+    if (testConfig.stackTraceLimit === "full") {
+        (<any>Error).stackTraceLimit = Infinity;
+    }
+    else if ((+testConfig.stackTraceLimit | 0) > 0) {
+        (<any>Error).stackTraceLimit = testConfig.stackTraceLimit;
+    }
+
     if (testConfig.test && testConfig.test.length > 0) {
         for (const option of testConfig.test) {
             if (!option) {

src/harness/rwcRunner.ts

@@ -79,6 +79,7 @@ namespace RWC {
                             useCaseSensitiveFileNames: Harness.IO.useCaseSensitiveFileNames(),
                             fileExists: Harness.IO.fileExists,
                             readDirectory: Harness.IO.readDirectory,
+                            readFile: Harness.IO.readFile
                         };
                         const configParseResult = ts.parseJsonConfigFileContent(parsedTsconfigFileContents.config, configParseHost, ts.getDirectoryPath(tsconfigFile.path));
                         fileNames = configParseResult.fileNames;
@@ -158,55 +159,56 @@ namespace RWC {
 
 
             it("has the expected emitted code", () => {
-                Harness.Baseline.runBaseline("has the expected emitted code", baseName + ".output.js", () => {
+                Harness.Baseline.runBaseline(`${baseName}.output.js`, () => {
                     return Harness.Compiler.collateOutputs(compilerResult.files);
-                }, false, baselineOpts);
+                }, baselineOpts);
             });
 
             it("has the expected declaration file content", () => {
-                Harness.Baseline.runBaseline("has the expected declaration file content", baseName + ".d.ts", () => {
+                Harness.Baseline.runBaseline(`${baseName}.d.ts`, () => {
                     if (!compilerResult.declFilesCode.length) {
                         return null;
                     }
 
                     return Harness.Compiler.collateOutputs(compilerResult.declFilesCode);
-                }, false, baselineOpts);
+                }, baselineOpts);
             });
 
             it("has the expected source maps", () => {
-                Harness.Baseline.runBaseline("has the expected source maps", baseName + ".map", () => {
+                Harness.Baseline.runBaseline(`${baseName}.map`, () => {
                     if (!compilerResult.sourceMaps.length) {
                         return null;
                     }
 
                     return Harness.Compiler.collateOutputs(compilerResult.sourceMaps);
-                }, false, baselineOpts);
+                }, baselineOpts);
             });
 
             /*it("has correct source map record", () => {
                 if (compilerOptions.sourceMap) {
-                    Harness.Baseline.runBaseline("has correct source map record", baseName + ".sourcemap.txt", () => {
+                    Harness.Baseline.runBaseline(baseName + ".sourcemap.txt", () => {
                         return compilerResult.getSourceMapRecord();
-                    }, false, baselineOpts);
+                    }, baselineOpts);
                 }
             });*/
 
             it("has the expected errors", () => {
-                Harness.Baseline.runBaseline("has the expected errors", baseName + ".errors.txt", () => {
+                Harness.Baseline.runBaseline(`${baseName}.errors.txt`, () => {
                     if (compilerResult.errors.length === 0) {
                         return null;
                     }
                     // Do not include the library in the baselines to avoid noise
                     const baselineFiles = inputFiles.concat(otherFiles).filter(f => !Harness.isDefaultLibraryFile(f.unitName));
-                    return Harness.Compiler.getErrorBaseline(baselineFiles, compilerResult.errors);
-                }, false, baselineOpts);
+                    const errors = compilerResult.errors.filter(e => !Harness.isDefaultLibraryFile(e.file.fileName));
+                    return Harness.Compiler.getErrorBaseline(baselineFiles, errors);
+                }, baselineOpts);
             });
 
             // Ideally, a generated declaration file will have no errors. But we allow generated
             // declaration file errors as part of the baseline.
             it("has the expected errors in generated declaration files", () => {
                 if (compilerOptions.declaration && !compilerResult.errors.length) {
-                    Harness.Baseline.runBaseline("has the expected errors in generated declaration files", baseName + ".dts.errors.txt", () => {
+                    Harness.Baseline.runBaseline(`${baseName}.dts.errors.txt`, () => {
                         const declFileCompilationResult = Harness.Compiler.compileDeclarationFiles(
                             inputFiles, otherFiles, compilerResult, /*harnessSettings*/ undefined, compilerOptions, currentDirectory);
 
@@ -217,11 +219,17 @@ namespace RWC {
                         return Harness.Compiler.minimalDiagnosticsToString(declFileCompilationResult.declResult.errors) +
                             Harness.IO.newLine() + Harness.IO.newLine() +
                             Harness.Compiler.getErrorBaseline(declFileCompilationResult.declInputFiles.concat(declFileCompilationResult.declOtherFiles), declFileCompilationResult.declResult.errors);
-                    }, false, baselineOpts);
+                    }, baselineOpts);
                 }
             });
 
-            // TODO: Type baselines (need to refactor out from compilerRunner)
+            it("has the expected types", () => {
+                // We don't need to pass the extension here because "doTypeAndSymbolBaseline" will append appropriate extension of ".types" or ".symbols"
+                Harness.Compiler.doTypeAndSymbolBaseline(baseName, compilerResult, inputFiles
+                    .concat(otherFiles)
+                    .filter(file => !!compilerResult.program.getSourceFile(file.unitName))
+                    .filter(e => !Harness.isDefaultLibraryFile(e.unitName)), baselineOpts);
+            });
         });
     }
 }

src/harness/test262Runner.ts

@@ -67,21 +67,21 @@ class Test262BaselineRunner extends RunnerBase {
             });
 
             it("has the expected emitted code", () => {
-                Harness.Baseline.runBaseline("has the expected emitted code", testState.filename + ".output.js", () => {
+                Harness.Baseline.runBaseline(testState.filename + ".output.js", () => {
                     const files = testState.compilerResult.files.filter(f => f.fileName !== Test262BaselineRunner.helpersFilePath);
                     return Harness.Compiler.collateOutputs(files);
-                }, false, Test262BaselineRunner.baselineOptions);
+                }, Test262BaselineRunner.baselineOptions);
             });
 
             it("has the expected errors", () => {
-                Harness.Baseline.runBaseline("has the expected errors", testState.filename + ".errors.txt", () => {
+                Harness.Baseline.runBaseline(testState.filename + ".errors.txt", () => {
                     const errors = testState.compilerResult.errors;
                     if (errors.length === 0) {
                         return null;
                     }
 
                     return Harness.Compiler.getErrorBaseline(testState.inputFiles, errors);
-                }, false, Test262BaselineRunner.baselineOptions);
+                }, Test262BaselineRunner.baselineOptions);
             });
 
             it("satisfies invariants", () => {
@@ -90,10 +90,10 @@ class Test262BaselineRunner extends RunnerBase {
             });
 
             it("has the expected AST", () => {
-                Harness.Baseline.runBaseline("has the expected AST", testState.filename + ".AST.txt", () => {
+                Harness.Baseline.runBaseline(testState.filename + ".AST.txt", () => {
                     const sourceFile = testState.compilerResult.program.getSourceFile(Test262BaselineRunner.getTestFilePath(testState.filename));
                     return Utils.sourceFileToJSON(sourceFile);
-                }, false, Test262BaselineRunner.baselineOptions);
+                }, Test262BaselineRunner.baselineOptions);
             });
         });
     }

src/harness/tsconfig.json

@@ -22,6 +22,19 @@
         "../compiler/utilities.ts",
         "../compiler/binder.ts",
         "../compiler/checker.ts",
+        "../compiler/factory.ts",
+        "../compiler/visitor.ts",
+        "../compiler/transformers/ts.ts",
+        "../compiler/transformers/jsx.ts",
+        "../compiler/transformers/es7.ts",
+        "../compiler/transformers/es6.ts",
+        "../compiler/transformers/generators.ts",
+        "../compiler/transformers/destructuring.ts",
+        "../compiler/transformers/module/module.ts",
+        "../compiler/transformers/module/system.ts",
+        "../compiler/transformers/module/es6.ts",
+        "../compiler/transformer.ts",
+        "../compiler/comments.ts",
         "../compiler/sourcemap.ts",
         "../compiler/declarationEmitter.ts",
         "../compiler/emitter.ts",
@@ -86,9 +99,14 @@
         "./unittests/moduleResolution.ts",
         "./unittests/tsconfigParsing.ts",
         "./unittests/commandLineParsing.ts",
+        "./unittests/configurationExtension.ts",
         "./unittests/convertCompilerOptionsFromJson.ts",
         "./unittests/convertTypingOptionsFromJson.ts",
         "./unittests/tsserverProjectSystem.ts",
-        "./unittests/matchFiles.ts"
+        "./unittests/matchFiles.ts",
+        "./unittests/initializeTSConfig.ts",
+        "./unittests/compileOnSave.ts",
+        "./unittests/typingsInstaller.ts",
+        "./unittests/projectErrors.ts"
     ]
 }

src/harness/typeWriter.ts

@@ -29,7 +29,7 @@ class TypeWriterWalker {
     }
 
     private visitNode(node: ts.Node): void {
-        if (ts.isExpression(node) || node.kind === ts.SyntaxKind.Identifier) {
+        if (ts.isPartOfExpression(node) || node.kind === ts.SyntaxKind.Identifier) {
             this.logTypeAndSymbol(node);
         }
 

src/harness/unittests/cachingInServerLSHost.ts

@@ -47,6 +47,7 @@ namespace ts {
                 return "";
             },
             getDirectories: (path: string) => [],
+            getEnvironmentVariable: (name: string) => "",
             readDirectory: (path: string, extension?: string[], exclude?: string[], include?: string[]): string[] => {
                 throw new Error("NYI");
             },
@@ -63,26 +64,29 @@ namespace ts {
                 };
             },
             setTimeout,
-            clearTimeout
+            clearTimeout,
+            setImmediate,
+            clearImmediate
         };
     }
 
     function createProject(rootFile: string, serverHost: server.ServerHost): { project: server.Project, rootScriptInfo: server.ScriptInfo } {
         const logger: server.Logger = {
             close() { },
-            isVerbose: () => false,
+            hasLevel: () => false,
             loggingEnabled: () => false,
             perftrc: (s: string) => { },
             info: (s: string) => { },
             startGroup: () => { },
             endGroup: () => { },
-            msg: (s: string, type?: string) => { }
+            msg: (s: string, type?: string) => { },
+            getLogFileName: (): string => undefined
         };
 
-        const projectService = new server.ProjectService(serverHost, logger);
-        const rootScriptInfo = projectService.openFile(rootFile, /* openedByClient */true);
-        const project = projectService.createInferredProject(rootScriptInfo);
-        project.setProjectOptions({ files: [rootScriptInfo.fileName], compilerOptions: { module: ts.ModuleKind.AMD } });
+        const projectService = new server.ProjectService(serverHost, logger, { isCancellationRequested: () => false }, /*useOneInferredProject*/ false, /*typingsInstaller*/ undefined);
+        const rootScriptInfo = projectService.getOrCreateScriptInfo(rootFile, /* openedByClient */true, /*containingProject*/ undefined);
+        const project = projectService.createInferredProjectWithRootFileIfNecessary(rootScriptInfo);
+        project.setCompilerOptions({ module: ts.ModuleKind.AMD } );
         return {
             project,
             rootScriptInfo
@@ -105,10 +109,9 @@ namespace ts {
             const { project, rootScriptInfo } = createProject(root.name, serverHost);
 
             // ensure that imported file was found
-            let diags = project.compilerService.languageService.getSemanticDiagnostics(imported.name);
+            let diags = project.getLanguageService().getSemanticDiagnostics(imported.name);
             assert.equal(diags.length, 1);
 
-            let content = rootScriptInfo.getText();
 
             const originalFileExists = serverHost.fileExists;
             {
@@ -120,10 +123,9 @@ namespace ts {
 
                 const newContent = `import {x} from "f1"
                 var x: string = 1;`;
-                rootScriptInfo.editContent(0, content.length, newContent);
-                content = newContent;
+                rootScriptInfo.editContent(0, root.content.length, newContent);
                 // trigger synchronization to make sure that import will be fetched from the cache
-                diags = project.compilerService.languageService.getSemanticDiagnostics(imported.name);
+                diags = project.getLanguageService().getSemanticDiagnostics(imported.name);
                 // ensure file has correct number of errors after edit
                 assert.equal(diags.length, 1);
             }
@@ -138,12 +140,11 @@ namespace ts {
                     return originalFileExists.call(serverHost, fileName);
                 };
                 const newContent = `import {x} from "f2"`;
-                rootScriptInfo.editContent(0, content.length, newContent);
-                content = newContent;
+                rootScriptInfo.editContent(0, root.content.length, newContent);
 
                 try {
                     // trigger synchronization to make sure that LSHost will try to find 'f2' module on disk
-                    project.compilerService.languageService.getSemanticDiagnostics(imported.name);
+                    project.getLanguageService().getSemanticDiagnostics(imported.name);
                     assert.isTrue(false, `should not find file '${imported.name}'`);
                 }
                 catch (e) {
@@ -164,20 +165,18 @@ namespace ts {
                 };
 
                 const newContent = `import {x} from "f1"`;
-                rootScriptInfo.editContent(0, content.length, newContent);
-                content = newContent;
-                project.compilerService.languageService.getSemanticDiagnostics(imported.name);
+                rootScriptInfo.editContent(0, root.content.length, newContent);
+                project.getLanguageService().getSemanticDiagnostics(imported.name);
                 assert.isTrue(fileExistsCalled);
 
                 // setting compiler options discards module resolution cache
                 fileExistsCalled = false;
 
-                const opts = ts.clone(project.projectOptions);
-                opts.compilerOptions = ts.clone(opts.compilerOptions);
-                opts.compilerOptions.target = ts.ScriptTarget.ES5;
-                project.setProjectOptions(opts);
+                const compilerOptions = ts.clone(project.getCompilerOptions());
+                compilerOptions.target = ts.ScriptTarget.ES5;
+                project.setCompilerOptions(compilerOptions);
 
-                project.compilerService.languageService.getSemanticDiagnostics(imported.name);
+                project.getLanguageService().getSemanticDiagnostics(imported.name);
                 assert.isTrue(fileExistsCalled);
             }
         });
@@ -210,8 +209,8 @@ namespace ts {
             };
 
             const { project, rootScriptInfo } = createProject(root.name, serverHost);
-            const content = rootScriptInfo.getText();
-            let diags = project.compilerService.languageService.getSemanticDiagnostics(root.name);
+
+            let diags = project.getLanguageService().getSemanticDiagnostics(root.name);
             assert.isTrue(fileExistsCalledForBar, "'fileExists' should be called");
             assert.isTrue(diags.length === 1, "one diagnostic expected");
             assert.isTrue(typeof diags[0].messageText === "string" && ((<string>diags[0].messageText).indexOf("Cannot find module") === 0), "should be 'cannot find module' message");
@@ -219,9 +218,9 @@ namespace ts {
             // assert that import will success once file appear on disk
             fileMap[imported.name] = imported;
             fileExistsCalledForBar = false;
-            rootScriptInfo.editContent(0, content.length, `import {y} from "bar"`);
+            rootScriptInfo.editContent(0, root.content.length, `import {y} from "bar"`);
 
-            diags = project.compilerService.languageService.getSemanticDiagnostics(root.name);
+            diags = project.getLanguageService().getSemanticDiagnostics(root.name);
             assert.isTrue(fileExistsCalledForBar, "'fileExists' should be called");
             assert.isTrue(diags.length === 0);
         });

src/harness/unittests/commandLineParsing.ts

@@ -60,7 +60,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,invalidOption", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -263,7 +263,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -283,7 +283,7 @@ namespace ts {
             assertParseResult(["--lib", "es5, ", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 

src/harness/unittests/compileOnSave.ts

@@ -0,0 +1,494 @@
+/// <reference path="../harness.ts" />
+/// <reference path="./tsserverProjectSystem.ts" />
+/// <reference path="../../server/typingsInstaller/typingsInstaller.ts" />
+
+namespace ts.projectSystem {
+    function createTestTypingsInstaller(host: server.ServerHost) {
+        return new TestTypingsInstaller("/a/data/", /*throttleLimit*/5, host);
+    }
+
+    describe("CompileOnSave affected list", () => {
+        function sendAffectedFileRequestAndCheckResult(session: server.Session, request: server.protocol.Request, expectedFileList: { projectFileName: string, files: FileOrFolder[] }[]) {
+            const response: server.protocol.CompileOnSaveAffectedFileListSingleProject[] = session.executeCommand(request).response;
+            const actualResult = response.sort((list1, list2) => compareStrings(list1.projectFileName, list2.projectFileName));
+            expectedFileList = expectedFileList.sort((list1, list2) => compareStrings(list1.projectFileName, list2.projectFileName));
+
+            assert.equal(actualResult.length, expectedFileList.length, `Actual result project number is different from the expected project number`);
+
+            for (let i = 0; i < actualResult.length; i++) {
+                const actualResultSingleProject = actualResult[i];
+                const expectedResultSingleProject = expectedFileList[i];
+                assert.equal(actualResultSingleProject.projectFileName, expectedResultSingleProject.projectFileName, `Actual result contains different projects than the expected result`);
+
+                const actualResultSingleProjectFileNameList = actualResultSingleProject.fileNames.sort();
+                const expectedResultSingleProjectFileNameList = map(expectedResultSingleProject.files, f => f.path).sort();
+                assert.isTrue(
+                    arrayIsEqualTo(actualResultSingleProjectFileNameList, expectedResultSingleProjectFileNameList),
+                    `For project ${actualResultSingleProject.projectFileName}, the actual result is ${actualResultSingleProjectFileNameList}, while expected ${expectedResultSingleProjectFileNameList}`);
+            }
+        }
+
+        describe("for configured projects", () => {
+            let moduleFile1: FileOrFolder;
+            let file1Consumer1: FileOrFolder;
+            let file1Consumer2: FileOrFolder;
+            let moduleFile2: FileOrFolder;
+            let globalFile3: FileOrFolder;
+            let configFile: FileOrFolder;
+            let changeModuleFile1ShapeRequest1: server.protocol.Request;
+            let changeModuleFile1InternalRequest1: server.protocol.Request;
+            let changeModuleFile1ShapeRequest2: server.protocol.Request;
+            // A compile on save affected file request using file1
+            let moduleFile1FileListRequest: server.protocol.Request;
+
+            beforeEach(() => {
+                moduleFile1 = {
+                    path: "/a/b/moduleFile1.ts",
+                    content: "export function Foo() { };"
+                };
+
+                file1Consumer1 = {
+                    path: "/a/b/file1Consumer1.ts",
+                    content: `import {Foo} from "./moduleFile1"; export var y = 10;`
+                };
+
+                file1Consumer2 = {
+                    path: "/a/b/file1Consumer2.ts",
+                    content: `import {Foo} from "./moduleFile1"; let z = 10;`
+                };
+
+                moduleFile2 = {
+                    path: "/a/b/moduleFile2.ts",
+                    content: `export var Foo4 = 10;`
+                };
+
+                globalFile3 = {
+                    path: "/a/b/globalFile3.ts",
+                    content: `interface GlobalFoo { age: number }`
+                };
+
+                configFile = {
+                    path: "/a/b/tsconfig.json",
+                    content: `{
+                        "compileOnSave": true
+                    }`
+                };
+
+                // Change the content of file1 to `export var T: number;export function Foo() { };`
+                changeModuleFile1ShapeRequest1 = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: moduleFile1.path,
+                    line: 1,
+                    offset: 1,
+                    endLine: 1,
+                    endOffset: 1,
+                    insertString: `export var T: number;`
+                });
+
+                // Change the content of file1 to `export var T: number;export function Foo() { };`
+                changeModuleFile1InternalRequest1 = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: moduleFile1.path,
+                    line: 1,
+                    offset: 1,
+                    endLine: 1,
+                    endOffset: 1,
+                    insertString: `var T1: number;`
+                });
+
+                // Change the content of file1 to `export var T: number;export function Foo() { };`
+                changeModuleFile1ShapeRequest2 = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: moduleFile1.path,
+                    line: 1,
+                    offset: 1,
+                    endLine: 1,
+                    endOffset: 1,
+                    insertString: `export var T2: number;`
+                });
+
+                moduleFile1FileListRequest = makeSessionRequest<server.protocol.FileRequestArgs>(server.CommandNames.CompileOnSaveAffectedFileList, { file: moduleFile1.path, projectFileName: configFile.path });
+            });
+
+            it("should contains only itself if a module file's shape didn't change, and all files referencing it if its shape changed", () => {
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer2, globalFile3, moduleFile2, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([moduleFile1, file1Consumer1], session);
+
+                // Send an initial compileOnSave request
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2] }]);
+                session.executeCommand(changeModuleFile1ShapeRequest1);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2] }]);
+
+                // Change the content of file1 to `export var T: number;export function Foo() { console.log('hi'); };`
+                const changeFile1InternalRequest = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: moduleFile1.path,
+                    line: 1,
+                    offset: 46,
+                    endLine: 1,
+                    endOffset: 46,
+                    insertString: `console.log('hi');`
+                });
+                session.executeCommand(changeFile1InternalRequest);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1] }]);
+            });
+
+            it("should be up-to-date with the reference map changes", () => {
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer2, globalFile3, moduleFile2, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([moduleFile1, file1Consumer1], session);
+
+                // Send an initial compileOnSave request
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2] }]);
+
+                // Change file2 content to `let y = Foo();`
+                const removeFile1Consumer1ImportRequest = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: file1Consumer1.path,
+                    line: 1,
+                    offset: 1,
+                    endLine: 1,
+                    endOffset: 28,
+                    insertString: ""
+                });
+                session.executeCommand(removeFile1Consumer1ImportRequest);
+                session.executeCommand(changeModuleFile1ShapeRequest1);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer2] }]);
+
+                // Add the import statements back to file2
+                const addFile2ImportRequest = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: file1Consumer1.path,
+                    line: 1,
+                    offset: 1,
+                    endLine: 1,
+                    endOffset: 1,
+                    insertString: `import {Foo} from "./moduleFile1";`
+                });
+                session.executeCommand(addFile2ImportRequest);
+
+                // Change the content of file1 to `export var T2: string;export var T: number;export function Foo() { };`
+                const changeModuleFile1ShapeRequest2 = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: moduleFile1.path,
+                    line: 1,
+                    offset: 1,
+                    endLine: 1,
+                    endOffset: 1,
+                    insertString: `export var T2: string;`
+                });
+                session.executeCommand(changeModuleFile1ShapeRequest2);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2] }]);
+            });
+
+            it("should be up-to-date with changes made in non-open files", () => {
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer2, globalFile3, moduleFile2, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([moduleFile1], session);
+
+                // Send an initial compileOnSave request
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2] }]);
+
+                file1Consumer1.content = `let y = 10;`;
+                host.reloadFS([moduleFile1, file1Consumer1, file1Consumer2, configFile, libFile]);
+                host.triggerFileWatcherCallback(file1Consumer1.path, /*removed*/ false);
+
+                session.executeCommand(changeModuleFile1ShapeRequest1);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer2] }]);
+            });
+
+            it("should be up-to-date with deleted files", () => {
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer2, globalFile3, moduleFile2, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([moduleFile1], session);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2] }]);
+
+                session.executeCommand(changeModuleFile1ShapeRequest1);
+                // Delete file1Consumer2
+                host.reloadFS([moduleFile1, file1Consumer1, configFile, libFile]);
+                host.triggerFileWatcherCallback(file1Consumer2.path, /*removed*/ true);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1] }]);
+            });
+
+            it("should be up-to-date with newly created files", () => {
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer2, globalFile3, moduleFile2, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([moduleFile1], session);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2] }]);
+
+                const file1Consumer3: FileOrFolder = {
+                    path: "/a/b/file1Consumer3.ts",
+                    content: `import {Foo} from "./moduleFile1"; let y = Foo();`
+                };
+                host.reloadFS([moduleFile1, file1Consumer1, file1Consumer2, file1Consumer3, globalFile3, configFile, libFile]);
+                host.triggerDirectoryWatcherCallback(ts.getDirectoryPath(file1Consumer3.path), file1Consumer3.path);
+                host.runQueuedTimeoutCallbacks();
+                session.executeCommand(changeModuleFile1ShapeRequest1);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2, file1Consumer3] }]);
+            });
+
+            it("should detect changes in non-root files", () => {
+                moduleFile1 = {
+                    path: "/a/b/moduleFile1.ts",
+                    content: "export function Foo() { };"
+                };
+
+                file1Consumer1 = {
+                    path: "/a/b/file1Consumer1.ts",
+                    content: `import {Foo} from "./moduleFile1"; let y = Foo();`
+                };
+
+                configFile = {
+                    path: "/a/b/tsconfig.json",
+                    content: `{
+                        "compileOnSave": true,
+                        "files": ["${file1Consumer1.path}"]
+                    }`
+                };
+
+                const host = createServerHost([moduleFile1, file1Consumer1, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([moduleFile1, file1Consumer1], session);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1] }]);
+
+                // change file1 shape now, and verify both files are affected
+                session.executeCommand(changeModuleFile1ShapeRequest1);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1] }]);
+
+                // change file1 internal, and verify only file1 is affected
+                session.executeCommand(changeModuleFile1InternalRequest1);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1] }]);
+            });
+
+            it("should return all files if a global file changed shape", () => {
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer2, globalFile3, moduleFile2, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([globalFile3], session);
+                const changeGlobalFile3ShapeRequest = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: globalFile3.path,
+                    line: 1,
+                    offset: 1,
+                    endLine: 1,
+                    endOffset: 1,
+                    insertString: `var T2: string;`
+                });
+
+                // check after file1 shape changes
+                session.executeCommand(changeGlobalFile3ShapeRequest);
+                const globalFile3FileListRequest = makeSessionRequest<server.protocol.FileRequestArgs>(server.CommandNames.CompileOnSaveAffectedFileList, { file: globalFile3.path });
+                sendAffectedFileRequestAndCheckResult(session, globalFile3FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer2, globalFile3, moduleFile2] }]);
+            });
+
+            it("should return empty array if CompileOnSave is not enabled", () => {
+                configFile = {
+                    path: "/a/b/tsconfig.json",
+                    content: `{}`
+                };
+
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer2, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+                openFilesForSession([moduleFile1], session);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, []);
+            });
+
+            it("should always return the file itself if '--isolatedModules' is specified", () => {
+                configFile = {
+                    path: "/a/b/tsconfig.json",
+                    content: `{
+                        "compileOnSave": true,
+                        "compilerOptions": {
+                            "isolatedModules": true
+                        }
+                    }`
+                };
+
+                const host = createServerHost([moduleFile1, file1Consumer1, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+                openFilesForSession([moduleFile1], session);
+
+                const file1ChangeShapeRequest = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: moduleFile1.path,
+                    line: 1,
+                    offset: 27,
+                    endLine: 1,
+                    endOffset: 27,
+                    insertString: `Point,`
+                });
+                session.executeCommand(file1ChangeShapeRequest);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1] }]);
+            });
+
+            it("should always return the file itself if '--out' or '--outFile' is specified", () => {
+                configFile = {
+                    path: "/a/b/tsconfig.json",
+                    content: `{
+                        "compileOnSave": true,
+                        "compilerOptions": {
+                            "module": "system",
+                            "outFile": "/a/b/out.js"
+                        }
+                    }`
+                };
+
+                const host = createServerHost([moduleFile1, file1Consumer1, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+                openFilesForSession([moduleFile1], session);
+
+                const file1ChangeShapeRequest = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: moduleFile1.path,
+                    line: 1,
+                    offset: 27,
+                    endLine: 1,
+                    endOffset: 27,
+                    insertString: `Point,`
+                });
+                session.executeCommand(file1ChangeShapeRequest);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1] }]);
+            });
+
+            it("should return cascaded affected file list", () => {
+                const file1Consumer1Consumer1: FileOrFolder = {
+                    path: "/a/b/file1Consumer1Consumer1.ts",
+                    content: `import {y} from "./file1Consumer1";`
+                };
+                const host = createServerHost([moduleFile1, file1Consumer1, file1Consumer1Consumer1, globalFile3, configFile, libFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([moduleFile1, file1Consumer1], session);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer1Consumer1] }]);
+
+                const changeFile1Consumer1ShapeRequest = makeSessionRequest<server.protocol.ChangeRequestArgs>(server.CommandNames.Change, {
+                    file: file1Consumer1.path,
+                    line: 2,
+                    offset: 1,
+                    endLine: 2,
+                    endOffset: 1,
+                    insertString: `export var T: number;`
+                });
+                session.executeCommand(changeModuleFile1ShapeRequest1);
+                session.executeCommand(changeFile1Consumer1ShapeRequest);
+                sendAffectedFileRequestAndCheckResult(session, moduleFile1FileListRequest, [{ projectFileName: configFile.path, files: [moduleFile1, file1Consumer1, file1Consumer1Consumer1] }]);
+            });
+
+            it("should work fine for files with circular references", () => {
+                const file1: FileOrFolder = {
+                    path: "/a/b/file1.ts",
+                    content: `
+                    /// <reference path="./file2.ts" />
+                    export var t1 = 10;`
+                };
+                const file2: FileOrFolder = {
+                    path: "/a/b/file2.ts",
+                    content: `
+                    /// <reference path="./file1.ts" />
+                    export var t2 = 10;`
+                };
+                const host = createServerHost([file1, file2, configFile]);
+                const typingsInstaller = createTestTypingsInstaller(host);
+                const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+                openFilesForSession([file1, file2], session);
+                const file1AffectedListRequest = makeSessionRequest<server.protocol.FileRequestArgs>(server.CommandNames.CompileOnSaveAffectedFileList, { file: file1.path });
+                sendAffectedFileRequestAndCheckResult(session, file1AffectedListRequest, [{ projectFileName: configFile.path, files: [file1, file2] }]);
+            });
+
+            it("should return results for all projects if not specifying projectFileName", () => {
+                const file1: FileOrFolder = { path: "/a/b/file1.ts", content: "export var t = 10;" };
+                const file2: FileOrFolder = { path: "/a/b/file2.ts", content: `import {t} from "./file1"; var t2 = 11;` };
+                const file3: FileOrFolder = { path: "/a/c/file2.ts", content: `import {t} from "../b/file1"; var t3 = 11;` };
+                const configFile1: FileOrFolder = { path: "/a/b/tsconfig.json", content: `{ "compileOnSave": true }` };
+                const configFile2: FileOrFolder = { path: "/a/c/tsconfig.json", content: `{ "compileOnSave": true }` };
+
+                const host = createServerHost([file1, file2, file3, configFile1, configFile2]);
+                const session = createSession(host);
+
+                openFilesForSession([file1, file2, file3], session);
+                const file1AffectedListRequest = makeSessionRequest<server.protocol.FileRequestArgs>(server.CommandNames.CompileOnSaveAffectedFileList, { file: file1.path });
+
+                sendAffectedFileRequestAndCheckResult(session, file1AffectedListRequest, [
+                    { projectFileName: configFile1.path, files: [file1, file2] },
+                    { projectFileName: configFile2.path, files: [file1, file3] }
+                ]);
+            });
+
+            it("should detect removed code file", () => {
+                const referenceFile1: FileOrFolder = {
+                    path: "/a/b/referenceFile1.ts",
+                    content: `
+                    /// <reference path="./moduleFile1.ts" />
+                    export var x = Foo();`
+                };
+                const host = createServerHost([moduleFile1, referenceFile1, configFile]);
+                const session = createSession(host);
+
+                openFilesForSession([referenceFile1], session);
+                host.reloadFS([referenceFile1, configFile]);
+                host.triggerFileWatcherCallback(moduleFile1.path, /*removed*/ true);
+
+                const request = makeSessionRequest<server.protocol.FileRequestArgs>(server.CommandNames.CompileOnSaveAffectedFileList, { file: referenceFile1.path });
+                sendAffectedFileRequestAndCheckResult(session, request, [
+                    { projectFileName: configFile.path, files: [referenceFile1] }
+                ]);
+                const requestForMissingFile = makeSessionRequest<server.protocol.FileRequestArgs>(server.CommandNames.CompileOnSaveAffectedFileList, { file: moduleFile1.path });
+                sendAffectedFileRequestAndCheckResult(session, requestForMissingFile, []);
+            });
+
+            it("should detect non-existing code file", () => {
+                const referenceFile1: FileOrFolder = {
+                    path: "/a/b/referenceFile1.ts",
+                    content: `
+                    /// <reference path="./moduleFile2.ts" />
+                    export var x = Foo();`
+                };
+                const host = createServerHost([referenceFile1, configFile]);
+                const session = createSession(host);
+
+                openFilesForSession([referenceFile1], session);
+                const request = makeSessionRequest<server.protocol.FileRequestArgs>(server.CommandNames.CompileOnSaveAffectedFileList, { file: referenceFile1.path });
+                sendAffectedFileRequestAndCheckResult(session, request, [
+                    { projectFileName: configFile.path, files: [referenceFile1] }
+                ]);
+            });
+        });
+    });
+
+    describe("EmitFile test", () => {
+        it("should emit specified file", () => {
+            const file1 = {
+                path: "/a/b/f1.ts",
+                content: `export function Foo() { return 10; }`
+            };
+            const file2 = {
+                path: "/a/b/f2.ts",
+                content: `import {Foo} from "./f1"; let y = Foo();`
+            };
+            const configFile = {
+                path: "/a/b/tsconfig.json",
+                content: `{}`
+            };
+            const host = createServerHost([file1, file2, configFile, libFile]);
+            const typingsInstaller = createTestTypingsInstaller(host);
+            const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+
+            openFilesForSession([file1, file2], session);
+            const compileFileRequest = makeSessionRequest<server.protocol.CompileOnSaveEmitFileRequestArgs>(server.CommandNames.CompileOnSaveEmitFile, { file: file1.path, projectFileName: configFile.path });
+            session.executeCommand(compileFileRequest);
+
+            const expectedEmittedFileName = "/a/b/f1.js";
+            assert.isTrue(host.fileExists(expectedEmittedFileName));
+            assert.equal(host.readFile(expectedEmittedFileName), `"use strict";\r\nfunction Foo() { return 10; }\r\nexports.Foo = Foo;\r\n`);
+        });
+    });
+}

src/harness/unittests/configurationExtension.ts

@@ -0,0 +1,187 @@
+/// <reference path="..\harness.ts" />
+/// <reference path="..\virtualFileSystem.ts" />
+
+namespace ts {
+    const testContents = {
+        "/dev/tsconfig.json": `{
+  "extends": "./configs/base",
+  "files": [
+    "main.ts",
+    "supplemental.ts"
+  ]
+}`,
+        "/dev/tsconfig.nostrictnull.json": `{
+  "extends": "./tsconfig",
+  "compilerOptions": {
+    "strictNullChecks": false
+  }
+}`,
+        "/dev/configs/base.json": `{
+  "compilerOptions": {
+    "allowJs": true,
+    "noImplicitAny": true,
+    "strictNullChecks": true
+  }
+}`,
+        "/dev/configs/tests.json": `{
+  "compilerOptions": {
+    "preserveConstEnums": true,
+    "removeComments": false,
+    "sourceMap": true
+  },
+  "exclude": [
+    "../tests/baselines",
+    "../tests/scenarios"
+  ],
+  "include": [
+    "../tests/**/*.ts"
+  ]
+}`,
+        "/dev/circular.json": `{
+    "extends": "./circular2",
+    "compilerOptions": {
+        "module": "amd"
+    }
+}`,
+        "/dev/circular2.json": `{
+    "extends": "./circular",
+    "compilerOptions": {
+        "module": "commonjs"
+    }
+}`,
+        "/dev/missing.json": `{
+    "extends": "./missing2",
+    "compilerOptions": {
+        "types": []
+    }
+}`,
+        "/dev/failure.json": `{
+    "extends": "./failure2.json",
+    "compilerOptions": {
+        "typeRoots": []
+    }
+}`,
+        "/dev/failure2.json": `{
+    "excludes": ["*.js"]
+}`,
+        "/dev/configs/first.json": `{
+    "extends": "./base",
+    "compilerOptions": {
+        "module": "commonjs"
+    },
+    "files": ["../main.ts"]
+}`,
+        "/dev/configs/second.json": `{
+    "extends": "./base",
+    "compilerOptions": {
+        "module": "amd"
+    },
+    "include": ["../supplemental.*"]
+}`,
+        "/dev/extends.json": `{ "extends": 42 }`,
+        "/dev/extends2.json": `{ "extends": "configs/base" }`,
+        "/dev/main.ts": "",
+        "/dev/supplemental.ts": "",
+        "/dev/tests/unit/spec.ts": "",
+        "/dev/tests/utils.ts": "",
+        "/dev/tests/scenarios/first.json": "",
+        "/dev/tests/baselines/first/output.ts": ""
+    };
+
+    const caseInsensitiveBasePath = "c:/dev/";
+    const caseInsensitiveHost = new Utils.MockParseConfigHost(caseInsensitiveBasePath, /*useCaseSensitiveFileNames*/ false, mapObject(testContents, (key, content) => [`c:${key}`, content]));
+
+    const caseSensitiveBasePath = "/dev/";
+    const caseSensitiveHost = new Utils.MockParseConfigHost(caseSensitiveBasePath, /*useCaseSensitiveFileNames*/ true, testContents);
+
+    function verifyDiagnostics(actual: Diagnostic[], expected: {code: number, category: DiagnosticCategory, messageText: string}[]) {
+        assert.isTrue(expected.length === actual.length, `Expected error: ${JSON.stringify(expected)}. Actual error: ${JSON.stringify(actual)}.`);
+        for (let i = 0; i < actual.length; i++) {
+            const actualError = actual[i];
+            const expectedError = expected[i];
+            assert.equal(actualError.code, expectedError.code, "Error code mismatch");
+            assert.equal(actualError.category, expectedError.category, "Category mismatch");
+            assert.equal(flattenDiagnosticMessageText(actualError.messageText, "\n"), expectedError.messageText);
+        }
+    }
+
+    describe("Configuration Extension", () => {
+        forEach<[string, string, Utils.MockParseConfigHost], void>([
+            ["under a case insensitive host", caseInsensitiveBasePath, caseInsensitiveHost],
+            ["under a case sensitive host", caseSensitiveBasePath, caseSensitiveHost]
+        ], ([testName, basePath, host]) => {
+            function testSuccess(name: string, entry: string, expected: CompilerOptions, expectedFiles: string[]) {
+                it(name, () => {
+                    const {config, error} = ts.readConfigFile(entry, name => host.readFile(name));
+                    assert(config && !error, flattenDiagnosticMessageText(error && error.messageText, "\n"));
+                    const parsed = ts.parseJsonConfigFileContent(config, host, basePath, {}, entry);
+                    assert(!parsed.errors.length, flattenDiagnosticMessageText(parsed.errors[0] && parsed.errors[0].messageText, "\n"));
+                    expected.configFilePath = entry;
+                    assert.deepEqual(parsed.options, expected);
+                    assert.deepEqual(parsed.fileNames, expectedFiles);
+                });
+            }
+
+            function testFailure(name: string, entry: string, expectedDiagnostics: {code: number, category: DiagnosticCategory, messageText: string}[]) {
+                it(name, () => {
+                    const {config, error} = ts.readConfigFile(entry, name => host.readFile(name));
+                    assert(config && !error, flattenDiagnosticMessageText(error && error.messageText, "\n"));
+                    const parsed = ts.parseJsonConfigFileContent(config, host, basePath, {}, entry);
+                    verifyDiagnostics(parsed.errors, expectedDiagnostics);
+                });
+            }
+
+            describe(testName, () => {
+                testSuccess("can resolve an extension with a base extension", "tsconfig.json", {
+                    allowJs: true,
+                    noImplicitAny: true,
+                    strictNullChecks: true,
+                }, [
+                    combinePaths(basePath, "main.ts"),
+                    combinePaths(basePath, "supplemental.ts"),
+                ]);
+
+                testSuccess("can resolve an extension with a base extension that overrides options", "tsconfig.nostrictnull.json", {
+                    allowJs: true,
+                    noImplicitAny: true,
+                    strictNullChecks: false,
+                }, [
+                    combinePaths(basePath, "main.ts"),
+                    combinePaths(basePath, "supplemental.ts"),
+                ]);
+
+                testFailure("can report errors on circular imports", "circular.json", [
+                    {
+                        code: 18000,
+                        category: DiagnosticCategory.Error,
+                        messageText: `Circularity detected while resolving configuration: ${[combinePaths(basePath, "circular.json"), combinePaths(basePath, "circular2.json"), combinePaths(basePath, "circular.json")].join(" -> ")}`
+                    }
+                ]);
+
+                testFailure("can report missing configurations", "missing.json", [{
+                    code: 6096,
+                    category: DiagnosticCategory.Message,
+                    messageText: `File './missing2' does not exist.`
+                }]);
+
+                testFailure("can report errors in extended configs", "failure.json", [{
+                    code: 6114,
+                    category: DiagnosticCategory.Error,
+                    messageText: `Unknown option 'excludes'. Did you mean 'exclude'?`
+                }]);
+
+                testFailure("can error when 'extends' is not a string", "extends.json", [{
+                    code: 5024,
+                    category: DiagnosticCategory.Error,
+                    messageText: `Compiler option 'extends' requires a value of type string.`
+                }]);
+
+                testFailure("can error when 'extends' is neither relative nor rooted.", "extends2.json", [{
+                    code: 18001,
+                    category: DiagnosticCategory.Error,
+                    messageText: `The path in an 'extends' options must be relative or rooted.`
+                }]);
+            });
+        });
+    });
+}

src/harness/unittests/convertCompilerOptionsFromJson.ts

@@ -233,7 +233,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -264,7 +264,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -295,7 +295,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -326,7 +326,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
+                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -403,6 +403,8 @@ namespace ts {
                 {
                     compilerOptions: <CompilerOptions>{
                         allowJs: true,
+                        maxNodeModuleJsDepth: 2,
+                        allowSyntheticDefaultImports: true,
                         module: ModuleKind.CommonJS,
                         target: ScriptTarget.ES5,
                         noImplicitAny: false,
@@ -429,6 +431,8 @@ namespace ts {
                 {
                     compilerOptions: <CompilerOptions>{
                         allowJs: false,
+                        maxNodeModuleJsDepth: 2,
+                        allowSyntheticDefaultImports: true,
                         module: ModuleKind.CommonJS,
                         target: ScriptTarget.ES5,
                         noImplicitAny: false,
@@ -450,7 +454,9 @@ namespace ts {
                 {
                     compilerOptions:
                     {
-                        allowJs: true
+                        allowJs: true,
+                        maxNodeModuleJsDepth: 2,
+                        allowSyntheticDefaultImports: true
                     },
                     errors: [{
                         file: undefined,
@@ -469,7 +475,9 @@ namespace ts {
                 {
                     compilerOptions:
                     {
-                        allowJs: true
+                        allowJs: true,
+                        maxNodeModuleJsDepth: 2,
+                        allowSyntheticDefaultImports: true
                     },
                     errors: <Diagnostic[]>[]
                 }

src/harness/unittests/initializeTSConfig.ts

@@ -0,0 +1,44 @@
+/// <reference path="..\harness.ts" />
+/// <reference path="..\..\compiler\commandLineParser.ts" />
+
+namespace ts {
+    describe("initTSConfig", () => {
+        function initTSConfigCorrectly(name: string, commandLinesArgs: string[]) {
+            describe(name, () => {
+                const commandLine = parseCommandLine(commandLinesArgs);
+                const initResult = generateTSConfig(commandLine.options, commandLine.fileNames);
+                const outputFileName = `tsConfig/${name.replace(/[^a-z0-9\-. ]/ig, "")}/tsconfig.json`;
+
+                it(`Correct output for ${outputFileName}`, () => {
+                    Harness.Baseline.runBaseline(outputFileName, () => {
+                        if (initResult) {
+                            return JSON.stringify(initResult, undefined, 4);
+                        }
+                        else {
+                            // This can happen if compiler recieve invalid compiler-options
+                            /* tslint:disable:no-null-keyword */
+                            return null;
+                            /* tslint:enable:no-null-keyword */
+                        }
+                    });
+                });
+            });
+        }
+
+        initTSConfigCorrectly("Default initialized TSConfig", ["--init"]);
+
+        initTSConfigCorrectly("Initialized TSConfig with files options", ["--init", "file0.st", "file1.ts", "file2.ts"]);
+
+        initTSConfigCorrectly("Initialized TSConfig with boolean value compiler options", ["--init", "--noUnusedLocals"]);
+
+        initTSConfigCorrectly("Initialized TSConfig with enum value compiler options", ["--init", "--target", "es5", "--jsx", "react"]);
+
+        initTSConfigCorrectly("Initialized TSConfig with list compiler options", ["--init", "--types", "jquery,mocha"]);
+
+        initTSConfigCorrectly("Initialized TSConfig with list compiler options with enum value", ["--init", "--lib", "es5,es2015.core"]);
+
+        initTSConfigCorrectly("Initialized TSConfig with incorrect compiler option", ["--init", "--someNonExistOption"]);
+
+        initTSConfigCorrectly("Initialized TSConfig with incorrect compiler option value", ["--init", "--lib", "nonExistLib,es5,es2015.promise"]);
+    });
+}

src/harness/unittests/moduleResolution.ts

@@ -446,8 +446,8 @@ export = C;
                 "/a/B/c/moduleB.ts": `import a = require("./moduleC")`,
                 "/a/B/c/moduleC.ts": "export var x",
                 "/a/B/c/moduleD.ts": `
-import a = require("./moduleA.ts");
-import b = require("./moduleB.ts");
+import a = require("./moduleA");
+import b = require("./moduleB");
                 `
             });
             test(files, { module: ts.ModuleKind.CommonJS, forceConsistentCasingInFileNames: true },  "/a/B/c", /*useCaseSensitiveFileNames*/ false, ["moduleD.ts"], [1149]);
@@ -458,8 +458,8 @@ import b = require("./moduleB.ts");
                 "/a/B/c/moduleB.ts": `import a = require("./moduleC")`,
                 "/a/B/c/moduleC.ts": "export var x",
                 "/a/B/c/moduleD.ts": `
-import a = require("./moduleA.ts");
-import b = require("./moduleB.ts");
+import a = require("./moduleA");
+import b = require("./moduleB");
                 `
             });
             test(files, { module: ts.ModuleKind.CommonJS, forceConsistentCasingInFileNames: true },  "/a/B/c", /*useCaseSensitiveFileNames*/ false, ["moduleD.ts"], []);

src/harness/unittests/projectErrors.ts

@@ -0,0 +1,186 @@
+/// <reference path="../harness.ts" />
+/// <reference path="./tsserverProjectSystem.ts" />
+/// <reference path="../../server/typingsInstaller/typingsInstaller.ts" />
+
+namespace ts.projectSystem {
+    describe("Project errors", () => {
+        function checkProjectErrors(projectFiles: server.ProjectFilesWithTSDiagnostics, expectedErrors: string[]) {
+            assert.isTrue(projectFiles !== undefined, "missing project files");
+            const errors = projectFiles.projectErrors;
+            assert.equal(errors ? errors.length : 0, expectedErrors.length, `expected ${expectedErrors.length} error in the list`);
+            if (expectedErrors.length) {
+                for (let i = 0; i < errors.length; i++) {
+                    const actualMessage = flattenDiagnosticMessageText(errors[i].messageText, "\n");
+                    const expectedMessage = expectedErrors[i];
+                    assert.isTrue(actualMessage.indexOf(expectedMessage) === 0, `error message does not match, expected ${actualMessage} to start with ${expectedMessage}`);
+                }
+            }
+        }
+
+        it("external project - diagnostics for missing files", () => {
+            const file1 = {
+                path: "/a/b/app.ts",
+                content: ""
+            };
+            const file2 = {
+                path: "/a/b/lib.ts",
+                content: ""
+            };
+            // only file1 exists - expect error
+            const host = createServerHost([file1]);
+            const projectService = createProjectService(host);
+            const projectFileName = "/a/b/test.csproj";
+
+            {
+                projectService.openExternalProject({
+                    projectFileName,
+                    options: {},
+                    rootFiles: toExternalFiles([file1.path, file2.path])
+                });
+
+                projectService.checkNumberOfProjects({ externalProjects: 1 });
+                const knownProjects = projectService.synchronizeProjectList([]);
+                checkProjectErrors(knownProjects[0], ["File '/a/b/lib.ts' not found."]);
+            }
+            // only file2 exists - expect error
+            host.reloadFS([file2]);
+            {
+                projectService.openExternalProject({
+                    projectFileName,
+                    options: {},
+                    rootFiles: toExternalFiles([file1.path, file2.path])
+                });
+                projectService.checkNumberOfProjects({ externalProjects: 1 });
+                const knownProjects = projectService.synchronizeProjectList([]);
+                checkProjectErrors(knownProjects[0], ["File '/a/b/app.ts' not found."]);
+            }
+
+            // both files exist - expect no errors
+            host.reloadFS([file1, file2]);
+            {
+                projectService.openExternalProject({
+                    projectFileName,
+                    options: {},
+                    rootFiles: toExternalFiles([file1.path, file2.path])
+                });
+
+                projectService.checkNumberOfProjects({ externalProjects: 1 });
+                const knownProjects = projectService.synchronizeProjectList([]);
+                checkProjectErrors(knownProjects[0], []);
+            }
+        });
+
+        it("configured projects - diagnostics for missing files", () => {
+            const file1 = {
+                path: "/a/b/app.ts",
+                content: ""
+            };
+            const file2 = {
+                path: "/a/b/lib.ts",
+                content: ""
+            };
+            const config = {
+                path: "/a/b/tsconfig.json",
+                content: JSON.stringify({ files: [file1, file2].map(f => getBaseFileName(f.path)) })
+            };
+            const host = createServerHost([file1, config]);
+            const projectService = createProjectService(host);
+
+            projectService.openClientFile(file1.path);
+            projectService.checkNumberOfProjects({ configuredProjects: 1 });
+            checkProjectErrors(projectService.synchronizeProjectList([])[0], ["File '/a/b/lib.ts' not found."]);
+
+            host.reloadFS([file1, file2, config]);
+
+            projectService.openClientFile(file1.path);
+            projectService.checkNumberOfProjects({ configuredProjects: 1 });
+            checkProjectErrors(projectService.synchronizeProjectList([])[0], []);
+        });
+
+        it("configured projects - diagnostics for corrupted config 1", () => {
+            const file1 = {
+                path: "/a/b/app.ts",
+                content: ""
+            };
+            const file2 = {
+                path: "/a/b/lib.ts",
+                content: ""
+            };
+            const correctConfig = {
+                path: "/a/b/tsconfig.json",
+                content: JSON.stringify({ files: [file1, file2].map(f => getBaseFileName(f.path)) })
+            };
+            const corruptedConfig = {
+                path: correctConfig.path,
+                content: correctConfig.content.substr(1)
+            };
+            const host = createServerHost([file1, file2, corruptedConfig]);
+            const projectService = createProjectService(host);
+
+            projectService.openClientFile(file1.path);
+            {
+                projectService.checkNumberOfProjects({ configuredProjects: 1 });
+                const configuredProject = forEach(projectService.synchronizeProjectList([]), f => f.info.projectName === corruptedConfig.path && f);
+                assert.isTrue(configuredProject !== undefined, "should find configured project");
+                checkProjectErrors(configuredProject,  [
+                    "')' expected.",
+                    "Declaration or statement expected.",
+                    "Declaration or statement expected.",
+                    "Failed to parse file '/a/b/tsconfig.json'"
+                ]);
+            }
+            // fix config and trigger watcher
+            host.reloadFS([file1, file2, correctConfig]);
+            host.triggerFileWatcherCallback(correctConfig.path, /*false*/);
+            {
+                projectService.checkNumberOfProjects({ configuredProjects: 1 });
+                const configuredProject = forEach(projectService.synchronizeProjectList([]), f => f.info.projectName === corruptedConfig.path && f);
+                assert.isTrue(configuredProject !== undefined, "should find configured project");
+                checkProjectErrors(configuredProject, []);
+            }
+        });
+
+        it("configured projects - diagnostics for corrupted config 2", () => {
+            const file1 = {
+                path: "/a/b/app.ts",
+                content: ""
+            };
+            const file2 = {
+                path: "/a/b/lib.ts",
+                content: ""
+            };
+            const correctConfig = {
+                path: "/a/b/tsconfig.json",
+                content: JSON.stringify({ files: [file1, file2].map(f => getBaseFileName(f.path)) })
+            };
+            const corruptedConfig = {
+                path: correctConfig.path,
+                content: correctConfig.content.substr(1)
+            };
+            const host = createServerHost([file1, file2, correctConfig]);
+            const projectService = createProjectService(host);
+
+            projectService.openClientFile(file1.path);
+            {
+                projectService.checkNumberOfProjects({ configuredProjects: 1 });
+                const configuredProject = forEach(projectService.synchronizeProjectList([]), f => f.info.projectName === corruptedConfig.path && f);
+                assert.isTrue(configuredProject !== undefined, "should find configured project");
+                checkProjectErrors(configuredProject, []);
+            }
+            // break config and trigger watcher
+            host.reloadFS([file1, file2, corruptedConfig]);
+            host.triggerFileWatcherCallback(corruptedConfig.path, /*false*/);
+            {
+                projectService.checkNumberOfProjects({ configuredProjects: 1 });
+                const configuredProject = forEach(projectService.synchronizeProjectList([]), f => f.info.projectName === corruptedConfig.path && f);
+                assert.isTrue(configuredProject !== undefined, "should find configured project");
+                checkProjectErrors(configuredProject, [
+                    "')' expected.",
+                    "Declaration or statement expected.",
+                    "Declaration or statement expected.",
+                    "Failed to parse file '/a/b/tsconfig.json'"
+                ]);
+            }
+        });
+    });
+}

src/harness/unittests/services/formatting/testCode/testCode/formatting/classes.ts

@@ -1,79 +0,0 @@
-         class                    a                  {    
-                                                        constructor       (       n   :                 number    )             ;
-                                                        constructor       (       s   :                 string    )             ;
-                                                        constructor       (       ns   :                 any    )                            {    
-
-                                                        }
-
-                                                            public                 pgF       (           )                            {                  }   ;
-
-                                                            public                 pv   ;
-                                                            public                 get              d       (           )                            {    
-                                                                                                                return              30   ;
-                                                        }
-                                                            public                 set              d       (           )                            {    
-                                                        }
-
-                                                            public                 static                    get              p2       (           )                            {    
-                                                                                                                return                  {                  x   :                 30   ,                  y   :                 40              }   ;
-                                                        }
-
-                                                                         private                static                    d2       (           )                            {    
-                                                        }
-                                                                         private                static                    get              p3       (           )                            {    
-                                                                                                                return              "string"   ;
-                                                        }
-                                                                         private                pv3   ;
-
-                                                                         private                foo       (       n   :                 number    )             :                 string   ;
-                                                                         private                foo       (       s   :                 string    )             :                 string   ;
-                                                                         private                foo       (       ns   :                 any    )                            {    
-                                                                                                                return              ns.toString       (           )             ;
-                                                        }
-}
-
-         class                    b              extends              a                  {    
-}
-
-         class   m1b      { 
-
-}
-
-                                                interface   m1ib                               { 
-                                                        
-  }
-         class                    c              extends              m1b                  {    
-}
-
-         class                    ib2              implements              m1ib                  {    
-}
-
-    declare                            class                    aAmbient                  {    
-                                                        constructor                     (       n   :                 number    )             ;
-                                                        constructor                     (       s   :                 string    )             ;
-                                                            public                 pgF       (           )             :                 void   ;
-                                                            public                 pv   ;
-                                                            public                 d                 :                 number   ;
-                                                        static                    p2                 :                     {                  x   :                 number   ;              y   :                 number   ;              }   ;
-                                                        static                    d2       (           )             ;
-                                                        static                    p3   ;
-                                                                         private                pv3   ;
-                                                                         private                foo       (       s    )             ;
-}
-
-         class                    d                  {    
-                                                                         private                foo       (       n   :                 number    )             :                 string   ;
-                                                                         private                foo       (       ns   :                 any    )                            {    
-                                                                                                                return              ns.toString       (           )             ;
-                                                        }
-                                                                         private                foo       (       s   :                 string    )             :                 string   ;
-}
-
-         class                    e                  {    
-                                                                         private                foo       (       ns   :                 any    )                            {    
-                                                                                                                return              ns.toString       (           )             ;
-                                                        }
-                                                                         private                foo       (       s   :                 string    )             :                 string   ;
-                                                                         private                foo       (       n   :                 number    )             :                 string   ;
-}
-

src/harness/unittests/services/formatting/testCode/testCode/formatting/classesBaseline.ts

@@ -1,79 +0,0 @@
-class a {
-    constructor(n: number);
-    constructor(s: string);
-    constructor(ns: any) {
-
-    }
-
-    public pgF() { };
-
-    public pv;
-    public get d() {
-        return 30;
-    }
-    public set d() {
-    }
-
-    public static get p2() {
-        return { x: 30, y: 40 };
-    }
-
-    private static d2() {
-    }
-    private static get p3() {
-        return "string";
-    }
-    private pv3;
-
-    private foo(n: number): string;
-    private foo(s: string): string;
-    private foo(ns: any) {
-        return ns.toString();
-    }
-}
-
-class b extends a {
-}
-
-class m1b {
-
-}
-
-interface m1ib {
-
-}
-class c extends m1b {
-}
-
-class ib2 implements m1ib {
-}
-
-declare class aAmbient {
-    constructor(n: number);
-    constructor(s: string);
-    public pgF(): void;
-    public pv;
-    public d: number;
-    static p2: { x: number; y: number; };
-    static d2();
-    static p3;
-    private pv3;
-    private foo(s);
-}
-
-class d {
-    private foo(n: number): string;
-    private foo(ns: any) {
-        return ns.toString();
-    }
-    private foo(s: string): string;
-}
-
-class e {
-    private foo(ns: any) {
-        return ns.toString();
-    }
-    private foo(s: string): string;
-    private foo(n: number): string;
-}
-

src/harness/unittests/services/formatting/testCode/testCode/formatting/colonAndQMark.ts

@@ -1,4 +0,0 @@
-class foo {
-    constructor (n?: number, m? = 5, o?: string = "") { }
-    x:number = 1?2:3;
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/colonAndQMarkBaseline.ts

@@ -1,4 +0,0 @@
-class foo {
-    constructor(n?: number, m? = 5, o?: string = "") { }
-    x: number = 1 ? 2 : 3;
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/documentReadyFunction.ts

@@ -1,3 +0,0 @@
-$    (   document   )   .  ready  (   function   (   )   {   
-    alert    (           'i am ready'  )   ;
-           }                 );

src/harness/unittests/services/formatting/testCode/testCode/formatting/documentReadyFunctionBaseLine.ts

@@ -1,3 +0,0 @@
-$(document).ready(function() {
-    alert('i am ready');
-});

src/harness/unittests/services/formatting/testCode/testCode/formatting/emptyBlock.ts

@@ -1 +0,0 @@
-{}

src/harness/unittests/services/formatting/testCode/testCode/formatting/emptyBlockBaseline.ts

@@ -1 +0,0 @@
-{ }

src/harness/unittests/services/formatting/testCode/testCode/formatting/emptyInterfaceLiteral.ts

@@ -1,10 +0,0 @@
-    function    foo  (  x  :    {    }    )    {    }
-
-foo    (  {     }   )    ;
-
-
-    
-            interface    bar    {
-                x   :    {     }   ;
-       y  :       (         )    =>    {     }   ;   
-                                                    }

src/harness/unittests/services/formatting/testCode/testCode/formatting/emptyInterfaceLiteralBaseLine.ts

@@ -1,10 +0,0 @@
-function foo(x: {}) { }
-
-foo({});
-
-
-
-interface bar {
-    x: {};
-    y: () => {};
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/fatArrowFunctions.ts

@@ -1,112 +0,0 @@
-// valid    
-    (         )           =>    1  ;   
-    (        arg )           =>    2  ;   
-        arg       =>    2  ;   
-      (        arg     = 1 )           =>    3  ;   
-    (        arg    ?        )           =>    4  ;   
-    (        arg    :    number )           =>    5  ;   
-      (        arg    :    number     = 0 )           =>    6  ;   
-    (        arg        ?                  :    number )           =>    7  ;   
-    (                 ...     arg    :    number   [      ]    )           =>    8  ;   
-      (        arg1   ,    arg2 )           =>    12  ;   
-    (        arg1     = 1   ,    arg2     =3 )           =>    13  ;   
-      (        arg1    ?          ,    arg2    ?        )           =>    14  ;   
-    (        arg1    :    number   ,    arg2    :    number )           =>    15  ;   
-    (        arg1    :    number     = 0   ,    arg2    :    number     = 1 )           =>    16  ;   
-      (        arg1    ?           :    number   ,    arg2    ?           :    number )           =>    17  ;   
-    (        arg1   ,             ...     arg2    :    number   [      ]    )           =>    18  ;   
-      (        arg1   ,    arg2    ?           :    number )           =>    19  ;   
-
-// in paren
-    (            (         )           =>    21 )      ;   
-    (            (        arg )           =>    22 )      ;   
-    (            (        arg     = 1 )           =>    23 )      ;   
-    (            (        arg    ?        )           =>    24 )      ;   
-    (            (        arg    :    number )           =>    25 )      ;   
-    (            (        arg    :    number     = 0 )           =>    26 )      ;   
-    (            (        arg    ?           :    number )           =>    27 )      ;   
-    (            (                 ...     arg    :    number   [      ]    )           =>    28 )      ;   
-
-// in multiple paren
-    (            (            (            (            (        arg )           =>    { return 32  ;    } )     )     )     )      ;   
-
-// in ternary exression
-      false        ?            (         )           =>    41     :    null  ;   
-   false        ?            (        arg )           =>    42     :    null  ;   
-    false        ?            (        arg     = 1 )           =>    43     :    null  ;   
-      false        ?            (        arg    ?        )           =>    44     :    null  ;   
-    false        ?            (        arg    :    number )           =>    45     :    null  ;   
-   false        ?            (        arg    ?           :    number )           =>    46     :    null  ;   
-      false        ?            (        arg    ?           :    number     = 0 )           =>    47     :    null  ;   
-   false        ?            (                 ...     arg    :    number   [      ]    )           =>    48     :    null  ;   
-
-// in ternary exression within paren
-   false        ?            (            (         )           =>    51 )         :    null  ;   
-    false        ?            (            (        arg )           =>    52 )         :    null  ;   
-    false        ?            (            (        arg     = 1 )           =>    53 )         :    null  ;   
-      false        ?            (            (        arg    ?        )           =>    54 )         :    null  ;   
-    false        ?            (            (        arg    :    number )           =>    55 )         :    null  ;   
-      false        ?            (            (        arg    ?           :    number )           =>    56 )         :    null  ;   
-    false        ?            (            (        arg    ?           :    number     = 0 )           =>    57 )         :    null  ;   
-   false        ?            (            (                 ...     arg    :    number   [      ]    )           =>    58 )         :    null  ;   
-
-// ternary exression's else clause
-   false        ?        null     :        (         )           =>    61  ;   
-        false        ?        null     :        (        arg )           =>    62  ;   
-   false        ?        null     :        (        arg     = 1 )           =>    63  ;   
-      false        ?        null     :        (        arg    ?        )           =>    64  ;   
-   false        ?        null     :        (        arg    :    number )           =>    65  ;   
-    false        ?        null     :        (        arg    ?           :    number )           =>    66  ;   
-        false        ?        null     :        (        arg    ?           :    number     = 0 )           =>    67  ;   
-    false        ?        null     :        (                 ...     arg    :    number   [      ]    )           =>    68  ;   
-
-
-// nested ternary expressions
-    (        a    ?        )           =>    { return a  ;    }     ?            (        b    ?         )           =>    { return b  ;    }     :        (        c    ?         )           =>    { return c  ;    }  ;   
-
-//multiple levels
-    (        a    ?        )           =>    { return a  ;    }     ?            (        b )          =>       (        c )          =>   81     :        (        c )          =>       (        d )          =>   82  ;   
-
-
-// In Expressions
-    (            (        arg )           =>    90 )     instanceof Function  ;   
-      (            (        arg     = 1 )           =>    91 )     instanceof Function  ;   
-        (            (        arg    ?         )           =>    92 )     instanceof Function  ;   
-      (            (        arg    :    number )           =>    93 )     instanceof Function  ;   
-    (            (        arg    :    number     = 1 )           =>    94 )     instanceof Function  ;   
-        (            (        arg    ?           :    number )           =>    95 )     instanceof Function  ;   
-      (            (                 ...     arg    :    number   [      ]    )           =>    96 )     instanceof Function  ;   
-
-''    +        (        arg )           =>    100  ;   
-        (            (        arg )           =>    0 )        +    ''    +        (        arg )           =>    101  ;   
-          (            (        arg     = 1 )           =>    0 )        +    ''    +        (        arg     = 2 )           =>    102  ;   
-    (            (        arg    ?        )           =>    0 )        +    ''    +        (        arg    ?        )           =>    103  ;   
-      (            (        arg    :   number )           =>    0 )        +    ''    +        (        arg    :   number )           =>    104  ;   
-        (            (        arg    :   number     = 1 )           =>    0 )        +    ''    +        (        arg    :   number     = 2 )           =>    105  ;   
-    (            (        arg    ?           :   number     = 1 )           =>    0 )        +    ''    +        (        arg    ?           :   number     = 2 )           =>    106  ;   
-      (            (                 ...     arg    :   number   [      ]    )           =>    0 )        +    ''    +        (                 ...     arg    :   number   [      ]    )           =>    107  ;   
-    (            (        arg1   ,    arg2    ?        )           =>    0 )        +    ''    +        (        arg1   ,   arg2    ?        )           =>    108  ;   
-      (            (        arg1   ,             ...     arg2    :   number   [      ]    )           =>    0 )        +    ''    +        (        arg1   ,             ...     arg2    :   number   [      ]    )           =>    108  ;   
-
-
-// Function Parameters
-function foo    (                 ...     arg    :    any   [      ]    )     { }
-
-foo    (        
-        (        a )           =>    110   ,    
-        (            (        a )           =>    111 )       ,    
-        (        a )           =>    {
-        return 112  ;   
-    }   ,   
-        (        a    ?         )           =>    113   ,    
-        (        a   ,    b    ?         )           =>    114   ,    
-        (        a    :    number )           =>    115   ,    
-        (        a    :    number     = 0 )           =>    116   ,    
-        (        a     = 0 )           =>    117   ,    
-        (        a    ?           :    number     = 0 )           =>    118   ,    
-        (        a    ?    ,   b   ?          :    number     = 0 )           =>    118   ,    
-        (                 ...     a    :    number   [      ]    )           =>    119   ,    
-        (        a   ,    b    ?            = 0   ,             ...     c    :    number   [      ]    )           =>    120   ,   
-        (        a )           =>        (        b )           =>        (        c )           =>    121   ,   
-        false       ?            (        a )           =>    0     :        (        b )           =>    122
- )      ;   

src/harness/unittests/services/formatting/testCode/testCode/formatting/fatArrowFunctionsBaseline.ts

@@ -1,112 +0,0 @@
-// valid    
-() => 1;
-(arg) => 2;
-arg => 2;
-(arg = 1) => 3;
-(arg?) => 4;
-(arg: number) => 5;
-(arg: number = 0) => 6;
-(arg?: number) => 7;
-(...arg: number[]) => 8;
-(arg1, arg2) => 12;
-(arg1 = 1, arg2 = 3) => 13;
-(arg1?, arg2?) => 14;
-(arg1: number, arg2: number) => 15;
-(arg1: number = 0, arg2: number = 1) => 16;
-(arg1?: number, arg2?: number) => 17;
-(arg1, ...arg2: number[]) => 18;
-(arg1, arg2?: number) => 19;
-
-// in paren
-(() => 21);
-((arg) => 22);
-((arg = 1) => 23);
-((arg?) => 24);
-((arg: number) => 25);
-((arg: number = 0) => 26);
-((arg?: number) => 27);
-((...arg: number[]) => 28);
-
-// in multiple paren
-(((((arg) => { return 32; }))));
-
-// in ternary exression
-false ? () => 41 : null;
-false ? (arg) => 42 : null;
-false ? (arg = 1) => 43 : null;
-false ? (arg?) => 44 : null;
-false ? (arg: number) => 45 : null;
-false ? (arg?: number) => 46 : null;
-false ? (arg?: number = 0) => 47 : null;
-false ? (...arg: number[]) => 48 : null;
-
-// in ternary exression within paren
-false ? (() => 51) : null;
-false ? ((arg) => 52) : null;
-false ? ((arg = 1) => 53) : null;
-false ? ((arg?) => 54) : null;
-false ? ((arg: number) => 55) : null;
-false ? ((arg?: number) => 56) : null;
-false ? ((arg?: number = 0) => 57) : null;
-false ? ((...arg: number[]) => 58) : null;
-
-// ternary exression's else clause
-false ? null : () => 61;
-false ? null : (arg) => 62;
-false ? null : (arg = 1) => 63;
-false ? null : (arg?) => 64;
-false ? null : (arg: number) => 65;
-false ? null : (arg?: number) => 66;
-false ? null : (arg?: number = 0) => 67;
-false ? null : (...arg: number[]) => 68;
-
-
-// nested ternary expressions
-(a?) => { return a; } ? (b?) => { return b; } : (c?) => { return c; };
-
-//multiple levels
-(a?) => { return a; } ? (b) => (c) => 81 : (c) => (d) => 82;
-
-
-// In Expressions
-((arg) => 90) instanceof Function;
-((arg = 1) => 91) instanceof Function;
-((arg?) => 92) instanceof Function;
-((arg: number) => 93) instanceof Function;
-((arg: number = 1) => 94) instanceof Function;
-((arg?: number) => 95) instanceof Function;
-((...arg: number[]) => 96) instanceof Function;
-
-'' + (arg) => 100;
-((arg) => 0) + '' + (arg) => 101;
-((arg = 1) => 0) + '' + (arg = 2) => 102;
-((arg?) => 0) + '' + (arg?) => 103;
-((arg: number) => 0) + '' + (arg: number) => 104;
-((arg: number = 1) => 0) + '' + (arg: number = 2) => 105;
-((arg?: number = 1) => 0) + '' + (arg?: number = 2) => 106;
-((...arg: number[]) => 0) + '' + (...arg: number[]) => 107;
-((arg1, arg2?) => 0) + '' + (arg1, arg2?) => 108;
-((arg1, ...arg2: number[]) => 0) + '' + (arg1, ...arg2: number[]) => 108;
-
-
-// Function Parameters
-function foo(...arg: any[]) { }
-
-foo(
-        (a) => 110,
-        ((a) => 111),
-        (a) => {
-            return 112;
-        },
-        (a?) => 113,
-        (a, b?) => 114,
-        (a: number) => 115,
-        (a: number = 0) => 116,
-        (a = 0) => 117,
-        (a?: number = 0) => 118,
-        (a?, b?: number = 0) => 118,
-        (...a: number[]) => 119,
-        (a, b? = 0, ...c: number[]) => 120,
-        (a) => (b) => (c) => 121,
-        false ? (a) => 0 : (b) => 122
- );

src/harness/unittests/services/formatting/testCode/testCode/formatting/formatDebuggerStatement.ts

@@ -1,2 +0,0 @@
-if(false){debugger;}
-  if    (   false   )   {    debugger  ;   }

src/harness/unittests/services/formatting/testCode/testCode/formatting/formatDebuggerStatementBaseline.ts

@@ -1,2 +0,0 @@
-if (false) { debugger; }
-if (false) { debugger; }

src/harness/unittests/services/formatting/testCode/testCode/formatting/formatvariableDeclarationList.ts

@@ -1,13 +0,0 @@
-var   fun1   =   function   (     )     {   
-            var               x   =   'foo'             ,
-                z   =   'bar'           ;
-                return  x            ;
-},
-
-fun2   =   (                function        (   f               )   {
-            var   fun   =   function   (        )       {
-                        console         .  log             (           f     (  )  )       ;
-            },
-            x   =   'Foo'           ;
-                return   fun            ;
-}   (           fun1            )   )       ;

src/harness/unittests/services/formatting/testCode/testCode/formatting/formatvariableDeclarationListBaseline.ts

@@ -1,13 +0,0 @@
-var fun1 = function() {
-    var x = 'foo',
-        z = 'bar';
-    return x;
-},
-
-fun2 = (function(f) {
-    var fun = function() {
-        console.log(f());
-    },
-    x = 'Foo';
-    return fun;
-} (fun1));

src/harness/unittests/services/formatting/testCode/testCode/formatting/implicitModule.ts

@@ -1,3 +0,0 @@
-        export class A {
-
-        }

src/harness/unittests/services/formatting/testCode/testCode/formatting/implicitModuleBaseline.ts

@@ -1,3 +0,0 @@
-export class A {
-
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/importDeclaration.ts

@@ -1,6 +0,0 @@
-module Foo {
-}
-
-import bar  =    Foo;
-
-import bar2=Foo;

src/harness/unittests/services/formatting/testCode/testCode/formatting/importDeclarationBaseline.ts

@@ -1,6 +0,0 @@
-module Foo {
-}
-
-import bar = Foo;
-
-import bar2 = Foo;

src/harness/unittests/services/formatting/testCode/testCode/formatting/main.ts

@@ -1,95 +0,0 @@
-
-var a;var c          , b;var  $d
-var $e 
-var f
-a++;b++;
-
-function        f     (     )        {
-    for (i = 0; i < 10; i++) {
-        k = abc + 123 ^ d;
-        a = XYZ[m  (a[b[c][d]])];
-        break;
-
-        switch ( variable){
-       case  1: abc += 425;
-break;
-case 404 : a [x--/2]%=3 ;
-                    break ;
-                case vari : v[--x ] *=++y*( m + n / k[z]);
-                for (a in b){
-             for (a = 0; a < 10; ++a) {
-              a++;--a;
-                   if (a == b) {
-                          a++;b--;
-                     }
-else
-if (a == c){
-++a;
-(--c)+=d;
-$c = $a + --$b;
-}
-if (a == b)
-if (a != b) {
- if (a !== b)
- if (a === b)
- --a;
- else
-  --a;
-  else {
-  a--;++b;
-a++
-                    }
-                    }
-                    }
-                    for (x in y) {
-m-=m;
-k=1+2+3+4;
-}
-}
-    break;
-                
-    }
-    }
-    var a  ={b:function(){}};
-    return {a:1,b:2}
-}
-
-var z = 1;
-            for (i = 0; i < 10; i++)
-     for (j = 0; j < 10; j++)
-for (k = 0; k < 10; ++k) { 
-z++;
-}
-
-for (k = 0; k < 10; k += 2) { 
-z++;
-}
-
-    $(document).ready ();
-
-
- function  pageLoad() {
- $('#TextBox1' ) .     unbind   (  ) ;
-$('#TextBox1' ) . datepicker ( ) ; 
-}
-
-        function pageLoad    (     )    {
-    var webclass=[
-                { 'student'     :
-                { 'id': '1', 'name': 'Linda Jones', 'legacySkill': 'Access, VB 5.0' }
-        }   ,
-{    'student':
-{'id':'2','name':'Adam Davidson','legacySkill':'Cobol,MainFrame'}
-}      ,
-    { 'student':
-{   'id':'3','name':'Charles Boyer' ,'legacySkill':'HTML, XML'}
-}
-    ];
-
-$create(Sys.UI.DataView,{data:webclass},null,null,$get('SList'));
-
-} 
-
-$( document ).ready(function(){
-alert('hello');
-    } ) ;

src/harness/unittests/services/formatting/testCode/testCode/formatting/mainBaseline.ts

@@ -1,98 +0,0 @@
-
-var a; var c, b; var $d
-var $e
-var f
-a++; b++;
-
-function f() {
-    for (i = 0; i < 10; i++) {
-        k = abc + 123 ^ d;
-        a = XYZ[m(a[b[c][d]])];
-        break;
-
-        switch (variable) {
-            case 1: abc += 425;
-                break;
-            case 404: a[x-- / 2] %= 3;
-                break;
-            case vari: v[--x] *= ++y * (m + n / k[z]);
-                for (a in b) {
-                    for (a = 0; a < 10; ++a) {
-                        a++; --a;
-                        if (a == b) {
-                            a++; b--;
-                        }
-                        else
-                            if (a == c) {
-                                ++a;
-                                (--c) += d;
-                                $c = $a + --$b;
-                            }
-                        if (a == b)
-                            if (a != b) {
-                                if (a !== b)
-                                    if (a === b)
-                                        --a;
-                                    else
-                                        --a;
-                                else {
-                                    a--; ++b;
-                                    a++
-                                }
-                            }
-                    }
-                    for (x in y) {
-                        m -= m;
-                        k = 1 + 2 + 3 + 4;
-                    }
-                }
-                break;
-
-        }
-    }
-    var a = { b: function() { } };
-    return { a: 1, b: 2 }
-}
-
-var z = 1;
-for (i = 0; i < 10; i++)
-    for (j = 0; j < 10; j++)
-        for (k = 0; k < 10; ++k) {
-            z++;
-        }
-
-for (k = 0; k < 10; k += 2) {
-    z++;
-}
-
-$(document).ready();
-
-
-function pageLoad() {
-    $('#TextBox1').unbind();
-    $('#TextBox1').datepicker();
-}
-
-function pageLoad() {
-    var webclass = [
-                {
-                    'student':
-                    { 'id': '1', 'name': 'Linda Jones', 'legacySkill': 'Access, VB 5.0' }
-                },
-{
-    'student':
-    { 'id': '2', 'name': 'Adam Davidson', 'legacySkill': 'Cobol,MainFrame' }
-},
-    {
-        'student':
-    { 'id': '3', 'name': 'Charles Boyer', 'legacySkill': 'HTML, XML' }
-    }
-    ];
-
-    $create(Sys.UI.DataView, { data: webclass }, null, null, $get('SList'));
-
-}
-
-$(document).ready(function() {
-    alert('hello');
-});

src/harness/unittests/services/formatting/testCode/testCode/formatting/moduleIndentation.ts

@@ -1,3 +0,0 @@
-   module     Foo    {
-     export    module    A  .   B  .   C     {      }
-                }

src/harness/unittests/services/formatting/testCode/testCode/formatting/moduleIndentationBaseline.ts

@@ -1,3 +0,0 @@
-module Foo {
-    export module A.B.C { }
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/modules.ts

@@ -1,76 +0,0 @@
-                     module                mod1                  {    
-                                                            export                                class                    b                  {    
-                                                        }
-                                                                 class                    d                  {    
-                                                        }
-
-
-                                                            export                       interface              ib                  {    
-                                                        }
-}
-
-                     module                m2                  {    
-
-                                                            export                                            module                m3                  {    
-                                                                                                                    export                                class                    c              extends              mod1.b                  {    
-                                                                                                                }
-                                                                                                                    export                                class                    ib2              implements              mod1.ib                  {    
-                                                                                                                }
-                                                        }
-}
-
-         class                    c              extends              mod1.b                  {    
-}
-
-         class                    ib2              implements              mod1.ib                  {    
-}
-
-                    declare               export           module         "m4"         {
-                                          export           class         d         {
-                                    }   ;     
-                                    var         x         :         d   ;     
-                                          export           function         foo      (           )     :         d   ;     
-}
-
-                 import         m4         =         module      (       "m4"    )        ;     
-      export           var         x4         =         m4.x   ;     
-      export           var         d4         =         m4.d   ;     
-      export           var         f4         =         m4.foo      (           )        ;     
-
-      export           module         m1         {
-                                                        declare               export           module         "m2"         {
-                                                                              export           class         d         {
-                                                                        }   ;     
-                                                                        var         x:         d   ;     
-                                                                              export           function         foo      (           )     :         d   ;     
-                                    }
-                                                     import         m2         =         module      (       "m2"    )        ;     
-                                                     import         m3         =         module      (       "m4"    )        ;     
-
-                                          export           var         x2         =         m2.x   ;     
-                                          export           var         d2         =         m2.d   ;     
-                                          export           var         f2         =         m2.foo      (           )        ;     
-
-                                          export           var         x3         =         m3.x   ;     
-                                          export           var         d3         =         m3.d   ;     
-                                          export           var         f3         =         m3.foo      (           )        ;     
-}
-
-      export           var         x2         =         m1.m2.x   ;     
-      export           var         d2         =         m1.m2.d   ;     
-      export           var         f2         =         m1.m2.foo      (           )        ;     
-
-      export           var         x3         =         m1.m3.x   ;     
-      export           var         d3         =         m1.m3.d   ;     
-      export           var         f3         =         m1.m3.foo      (           )        ;     
-
-      export           module         m5         {
-                                          export           var         x2         =         m1.m2.x   ;     
-                                          export           var         d2         =         m1.m2.d   ;     
-                                          export           var         f2         =         m1.m2.foo      (           )        ;     
-
-                                          export           var         x3         =         m1.m3.x   ;     
-                                          export           var         d3         =         m1.m3.d   ;     
-                                          export           var         f3         =         m1.m3.foo      (           )        ;     
-}
-

src/harness/unittests/services/formatting/testCode/testCode/formatting/modulesBaseline.ts

@@ -1,76 +0,0 @@
-module mod1 {
-    export class b {
-    }
-    class d {
-    }
-
-
-    export interface ib {
-    }
-}
-
-module m2 {
-
-    export module m3 {
-        export class c extends mod1.b {
-        }
-        export class ib2 implements mod1.ib {
-        }
-    }
-}
-
-class c extends mod1.b {
-}
-
-class ib2 implements mod1.ib {
-}
-
-declare export module "m4" {
-    export class d {
-    };
-    var x: d;
-    export function foo(): d;
-}
-
-import m4 = module("m4");
-export var x4 = m4.x;
-export var d4 = m4.d;
-export var f4 = m4.foo();
-
-export module m1 {
-    declare export module "m2" {
-        export class d {
-        };
-        var x: d;
-        export function foo(): d;
-    }
-    import m2 = module("m2");
-    import m3 = module("m4");
-
-    export var x2 = m2.x;
-    export var d2 = m2.d;
-    export var f2 = m2.foo();
-
-    export var x3 = m3.x;
-    export var d3 = m3.d;
-    export var f3 = m3.foo();
-}
-
-export var x2 = m1.m2.x;
-export var d2 = m1.m2.d;
-export var f2 = m1.m2.foo();
-
-export var x3 = m1.m3.x;
-export var d3 = m1.m3.d;
-export var f3 = m1.m3.foo();
-
-export module m5 {
-    export var x2 = m1.m2.x;
-    export var d2 = m1.m2.d;
-    export var f2 = m1.m2.foo();
-
-    export var x3 = m1.m3.x;
-    export var d3 = m1.m3.d;
-    export var f3 = m1.m3.foo();
-}
-

src/harness/unittests/services/formatting/testCode/testCode/formatting/objectLiteral.ts

@@ -1,27 +0,0 @@
-var x = {foo: 1,
-bar: "tt",
-boo: 1 + 5};
-
-var x2 = {foo: 1,
-bar: "tt",boo:1+5};
-
-function Foo() {
-var typeICalc = {
-clear: {
-"()": [1, 2, 3]
-}
-}
-}
-
-// Rule for object literal members for the "value" of the memebr to follow the indent
-// of the member, i.e. the relative position of the value is maintained when the member
-// is indented.
-var x2 = {
-  foo:
-3,
-          'bar':
-                    { a: 1, b : 2}
-};
-
-var x={    };
-var y = {};

src/harness/unittests/services/formatting/testCode/testCode/formatting/objectLiteralBaseline.ts

@@ -1,31 +0,0 @@
-var x = {
-    foo: 1,
-    bar: "tt",
-    boo: 1 + 5
-};
-
-var x2 = {
-    foo: 1,
-    bar: "tt", boo: 1 + 5
-};
-
-function Foo() {
-    var typeICalc = {
-        clear: {
-            "()": [1, 2, 3]
-        }
-    }
-}
-
-// Rule for object literal members for the "value" of the memebr to follow the indent
-// of the member, i.e. the relative position of the value is maintained when the member
-// is indented.
-var x2 = {
-    foo:
-  3,
-    'bar':
-              { a: 1, b: 2 }
-};
-
-var x = {};
-var y = {};

src/harness/unittests/services/formatting/testCode/testCode/formatting/onClosingBracket.ts

@@ -1,32 +0,0 @@
-function f( ) {
-var     x = 3;
-    var z = 2   ;
-    a  = z  ++ - 2 *  x ;
-        for ( ; ; ) {
-    a+=(g +g)*a%t;
-        b --                          ;
-}
-
-    switch ( a  )
-    {
-        case 1  :     {
-    a ++  ;
-        b--;
-    if(a===a)
-                return;
-    else
-        {
-            for(a in b)
-                if(a!=a)
-    {
-    for(a in b)
-            {
-a++;
-        }
-                }
-    }
-        }
-    default:
-        break;
-    }
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/onClosingBracketBaseLine.ts

@@ -1,28 +0,0 @@
-function f() {
-    var x = 3;
-    var z = 2;
-    a = z++ - 2 * x;
-    for (; ;) {
-        a += (g + g) * a % t;
-        b--;
-    }
-
-    switch (a) {
-        case 1: {
-            a++;
-            b--;
-            if (a === a)
-                return;
-            else {
-                for (a in b)
-                    if (a != a) {
-                        for (a in b) {
-                            a++;
-                        }
-                    }
-            }
-        }
-        default:
-            break;
-    }
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/onSemiColon.ts

@@ -1 +0,0 @@
-var  a=b+c^d-e*++f;

src/harness/unittests/services/formatting/testCode/testCode/formatting/onSemiColonBaseline.ts

@@ -1 +0,0 @@
-var a = b + c ^ d - e * ++f;

src/harness/unittests/services/formatting/testCode/testCode/formatting/spaceAfterConstructor.ts

@@ -1 +0,0 @@
-class test { constructor                   () { } }

src/harness/unittests/services/formatting/testCode/testCode/formatting/spaceAfterConstructorBaseline.ts

@@ -1 +0,0 @@
-class test { constructor() { } }

src/harness/unittests/services/formatting/testCode/testCode/formatting/tabAfterCloseCurly.ts

@@ -1,10 +0,0 @@
-module Tools {
-    export enum NodeType {
-        Error,
-        Comment,
-    }	
-    export enum foob
-    {
-        Blah=1, Bleah=2
-    }
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/tabAfterCloseCurlyBaseline.ts

@@ -1,9 +0,0 @@
-module Tools {
-    export enum NodeType {
-        Error,
-        Comment,
-    }
-    export enum foob {
-        Blah = 1, Bleah = 2
-    }
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/typescriptConstructs.ts

@@ -1,65 +0,0 @@
-     module MyModule 
-     {
-                module A.B.C {
-module F {
-}
-                   }
-interface Blah 
-{
-boo: string;
-}
-    
- class Foo 
- {
-      
-}
-      
-class Foo2 {
-public foo():number {
-return 5 * 6;
-}
-public foo2() {
-if (1 === 2)
-                          
-
-{
-var y     :   number= 76;
-return y;
-}
-
-                            while (2 == 3)               {              
-  if (    y      ==       null     )       {     
-                    
-}
- }
-}
-
-public foo3() {
-if (1 === 2)
-                          
-//comment preventing line merging
-{
-var y = 76;
-return y;
-}
-
-}
- }
-     }
-
-function foo(a:number, b:number):number
-{
-return 0;
-}
-
-function bar(a:number, b:number) :number[]       {
-return [];
-}
-
-module BugFix3 {
-declare var f: { 
- (): any;
-   (x: number): string;
-       foo: number;
-};
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/typescriptConstructsBaseline.ts

@@ -1,58 +0,0 @@
-module MyModule {
-    module A.B.C {
-        module F {
-        }
-    }
-    interface Blah {
-        boo: string;
-    }
-
-    class Foo {
-
-    }
-
-    class Foo2 {
-        public foo(): number {
-            return 5 * 6;
-        }
-        public foo2() {
-            if (1 === 2) {
-                var y: number = 76;
-                return y;
-            }
-
-            while (2 == 3) {
-                if (y == null) {
-
-                }
-            }
-        }
-
-        public foo3() {
-            if (1 === 2)
-
-                //comment preventing line merging
-            {
-                var y = 76;
-                return y;
-            }
-
-        }
-    }
-}
-
-function foo(a: number, b: number): number {
-    return 0;
-}
-
-function bar(a: number, b: number): number[] {
-    return [];
-}
-
-module BugFix3 {
-    declare var f: {
-        (): any;
-        (x: number): string;
-        foo: number;
-    };
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/various.ts

@@ -1,17 +0,0 @@
-function f(a,b,c,d){
-for(var i=0;i<10;i++){
-var a=0;
-var b=a+a+a*a%a/2-1;
-b+=a;
-++b;
-f(a,b,c,d);
-if(1===1){
-var m=function(e,f){
-return e^f;
-}
-}
-}
-}
-
-for (var i = 0   ; i < this.foo(); i++) {
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/variousBaseline.ts

@@ -1,17 +0,0 @@
-function f(a, b, c, d) {
-    for (var i = 0; i < 10; i++) {
-        var a = 0;
-        var b = a + a + a * a % a / 2 - 1;
-        b += a;
-        ++b;
-        f(a, b, c, d);
-        if (1 === 1) {
-            var m = function(e, f) {
-                return e ^ f;
-            }
-        }
-    }
-}
-
-for (var i = 0   ; i < this.foo(); i++) {
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/withStatement.ts

@@ -1,9 +0,0 @@
-with (foo.bar) 
-
-   {
-
-     }
-
-with (bar.blah)
-{
-}

src/harness/unittests/services/formatting/testCode/testCode/formatting/withStatementBaseline.ts

@@ -1,6 +0,0 @@
-with (foo.bar) {
-
-}
-
-with (bar.blah) {
-}

src/harness/unittests/session.ts

@@ -18,20 +18,25 @@ namespace ts.server {
         createDirectory(): void {},
         getExecutingFilePath(): string { return void 0; },
         getCurrentDirectory(): string { return void 0; },
+        getEnvironmentVariable(name: string): string { return ""; },
         readDirectory(): string[] { return []; },
         exit(): void { },
         setTimeout(callback, ms, ...args) { return 0; },
-        clearTimeout(timeoutId) { }
+        clearTimeout(timeoutId) { },
+        setImmediate: () => 0,
+        clearImmediate() {}
     };
+    const nullCancellationToken: HostCancellationToken = { isCancellationRequested: () => false };
     const mockLogger: Logger = {
         close(): void {},
-        isVerbose(): boolean { return false; },
+        hasLevel(): boolean { return false; },
         loggingEnabled(): boolean { return false; },
         perftrc(s: string): void {},
         info(s: string): void {},
         startGroup(): void {},
         endGroup(): void {},
         msg(s: string, type?: string): void {},
+        getLogFileName: (): string => undefined
     };
 
     describe("the Session class", () => {
@@ -39,7 +44,7 @@ namespace ts.server {
         let lastSent: protocol.Message;
 
         beforeEach(() => {
-            session = new Session(mockHost, Utils.byteLength, process.hrtime, mockLogger);
+            session = new Session(mockHost, nullCancellationToken, /*useOneInferredProject*/ false, /*typingsInstaller*/ undefined, Utils.byteLength, process.hrtime, mockLogger, /*canUseEvents*/ true);
             session.send = (msg: protocol.Message) => {
                 lastSent = msg;
             };
@@ -264,7 +269,7 @@ namespace ts.server {
             lastSent: protocol.Message;
             customHandler = "testhandler";
             constructor() {
-                super(mockHost, Utils.byteLength, process.hrtime, mockLogger);
+                super(mockHost, nullCancellationToken, /*useOneInferredProject*/ false, /*typingsInstaller*/ undefined, Utils.byteLength, process.hrtime, mockLogger, /*canUseEvents*/ true);
                 this.addProtocolHandler(this.customHandler, () => {
                     return { response: undefined, responseRequired: true };
                 });
@@ -322,7 +327,7 @@ namespace ts.server {
         class InProcSession extends Session {
             private queue: protocol.Request[] = [];
             constructor(private client: InProcClient) {
-                super(mockHost, Utils.byteLength, process.hrtime, mockLogger);
+                super(mockHost, nullCancellationToken, /*useOneInferredProject*/ false, /*typingsInstaller*/ undefined, Utils.byteLength, process.hrtime, mockLogger, /*canUseEvents*/ true);
                 this.addProtocolHandler("echo", (req: protocol.Request) => ({
                     response: req.arguments,
                     responseRequired: true

src/harness/unittests/transpile.ts

@@ -62,7 +62,7 @@ namespace ts {
                 });
 
                 it("Correct errors for " + justName, () => {
-                    Harness.Baseline.runBaseline("Correct errors", justName.replace(/\.tsx?$/, ".errors.txt"), () => {
+                    Harness.Baseline.runBaseline(justName.replace(/\.tsx?$/, ".errors.txt"), () => {
                         if (transpileResult.diagnostics.length === 0) {
                             /* tslint:disable:no-null-keyword */
                             return null;
@@ -75,7 +75,7 @@ namespace ts {
 
                 if (canUseOldTranspile) {
                     it("Correct errors (old transpile) for " + justName, () => {
-                        Harness.Baseline.runBaseline("Correct errors", justName.replace(/\.tsx?$/, ".oldTranspile.errors.txt"), () => {
+                        Harness.Baseline.runBaseline(justName.replace(/\.tsx?$/, ".oldTranspile.errors.txt"), () => {
                             if (oldTranspileDiagnostics.length === 0) {
                                 /* tslint:disable:no-null-keyword */
                                 return null;
@@ -88,7 +88,7 @@ namespace ts {
                 }
 
                 it("Correct output for " + justName, () => {
-                    Harness.Baseline.runBaseline("Correct output", justName.replace(/\.tsx?$/, ".js"), () => {
+                    Harness.Baseline.runBaseline(justName.replace(/\.tsx?$/, ".js"), () => {
                         if (transpileResult.outputText) {
                             return transpileResult.outputText;
                         }
@@ -101,10 +101,9 @@ namespace ts {
                     });
                 });
 
-
                 if (canUseOldTranspile) {
                     it("Correct output (old transpile) for " + justName, () => {
-                        Harness.Baseline.runBaseline("Correct output", justName.replace(/\.tsx?$/, ".oldTranspile.js"), () => {
+                        Harness.Baseline.runBaseline(justName.replace(/\.tsx?$/, ".oldTranspile.js"), () => {
                             return oldTranspileResult;
                         });
                     });

src/harness/unittests/tsconfigParsing.ts

@@ -151,7 +151,7 @@ namespace ts {
             );
         });
 
-        it("always exclude outDir", () => {
+        it("exclude outDir unless overridden", () => {
             const tsconfigWithoutExclude =
             `{
                 "compilerOptions": {
@@ -169,7 +169,7 @@ namespace ts {
             const allFiles = ["/bin/a.ts", "/b.ts"];
             const expectedFiles = ["/b.ts"];
             assertParseFileList(tsconfigWithoutExclude, "tsconfig.json", rootDir, allFiles, expectedFiles);
-            assertParseFileList(tsconfigWithExclude, "tsconfig.json", rootDir, allFiles, expectedFiles);
+            assertParseFileList(tsconfigWithExclude, "tsconfig.json", rootDir, allFiles, allFiles);
         });
 
         it("implicitly exclude common package folders", () => {
@@ -181,5 +181,26 @@ namespace ts {
                 ["/d.ts", "/folder/e.ts"]
             );
         });
+
+        it("parse and re-emit tsconfig.json file with diagnostics", () => {
+            const content = `{
+                "compilerOptions": {
+                    "allowJs": true
+                    // Some comments
+                    "outDir": "bin"
+                }
+                "files": ["file1.ts"]
+            }`;
+            const { configJsonObject, diagnostics } = sanitizeConfigFile("config.json", content);
+            const expectedResult = {
+                compilerOptions: {
+                    allowJs: true,
+                    outDir: "bin"
+                },
+                files: ["file1.ts"]
+            };
+            assert.isTrue(diagnostics.length === 2);
+            assert.equal(JSON.stringify(configJsonObject), JSON.stringify(expectedResult));
+        });
     });
 }

src/harness/unittests/typingsInstaller.ts

@@ -0,0 +1,723 @@
+/// <reference path="../harness.ts" />
+/// <reference path="./tsserverProjectSystem.ts" />
+/// <reference path="../../server/typingsInstaller/typingsInstaller.ts" />
+
+namespace ts.projectSystem {
+    import TI = server.typingsInstaller;
+
+    interface InstallerParams {
+        globalTypingsCacheLocation?: string;
+        throttleLimit?: number;
+    }
+
+    class Installer extends TestTypingsInstaller {
+        constructor(host: server.ServerHost, p?: InstallerParams) {
+            super(
+                (p && p.globalTypingsCacheLocation) || "/a/data",
+                (p && p.throttleLimit) || 5,
+                host);
+        }
+
+        installAll(expectedView: typeof TI.NpmViewRequest[], expectedInstall: typeof TI.NpmInstallRequest[]) {
+            this.checkPendingCommands(expectedView);
+            this.executePendingCommands();
+            this.checkPendingCommands(expectedInstall);
+            this.executePendingCommands();
+        }
+    }
+
+    describe("typingsInstaller", () => {
+        function executeCommand(self: Installer, host: TestServerHost, installedTypings: string[], typingFiles: FileOrFolder[], requestKind: TI.RequestKind, cb: TI.RequestCompletedAction): void {
+            switch (requestKind) {
+                case TI.NpmInstallRequest:
+                    self.addPostExecAction(requestKind, installedTypings, (err, stdout, stderr) => {
+                        for (const file of typingFiles) {
+                            host.createFileOrFolder(file, /*createParentDirectory*/ true);
+                        }
+                        cb(err, stdout, stderr);
+                    });
+                    break;
+                case TI.NpmViewRequest:
+                    self.addPostExecAction(requestKind, installedTypings, cb);
+                    break;
+                default:
+                    assert.isTrue(false, `unexpected request kind ${requestKind}`);
+                    break;
+            }
+        }
+        it("configured projects (typings installed) 1", () => {
+            const file1 = {
+                path: "/a/b/app.js",
+                content: ""
+            };
+            const tsconfig = {
+                path: "/a/b/tsconfig.json",
+                content: JSON.stringify({
+                    compilerOptions: {
+                        allowJs: true
+                    },
+                    typingOptions: {
+                        enableAutoDiscovery: true
+                    }
+                })
+            };
+            const packageJson = {
+                path: "/a/b/package.json",
+                content: JSON.stringify({
+                    name: "test",
+                    dependencies: {
+                        jquery: "^3.1.0"
+                    }
+                })
+            };
+
+            const jquery = {
+                path: "/a/data/node_modules/@types/jquery/index.d.ts",
+                content: "declare const $: { x: number }"
+            };
+            const host = createServerHost([file1, tsconfig, packageJson]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                    const installedTypings = ["@types/jquery"];
+                    const typingFiles = [jquery];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectService = createProjectService(host, { useSingleInferredProject: true, typingsInstaller: installer });
+            projectService.openClientFile(file1.path);
+
+            checkNumberOfProjects(projectService, { configuredProjects: 1 });
+            const p = projectService.configuredProjects[0];
+            checkProjectActualFiles(p, [file1.path]);
+
+            installer.installAll([TI.NpmViewRequest], [TI.NpmInstallRequest]);
+
+            checkNumberOfProjects(projectService, { configuredProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, jquery.path]);
+        });
+
+        it("inferred project (typings installed)", () => {
+            const file1 = {
+                path: "/a/b/app.js",
+                content: ""
+            };
+            const packageJson = {
+                path: "/a/b/package.json",
+                content: JSON.stringify({
+                    name: "test",
+                    dependencies: {
+                        jquery: "^3.1.0"
+                    }
+                })
+            };
+
+            const jquery = {
+                path: "/a/data/node_modules/@types/jquery/index.d.ts",
+                content: "declare const $: { x: number }"
+            };
+            const host = createServerHost([file1, packageJson]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                    const installedTypings = ["@types/jquery"];
+                    const typingFiles = [jquery];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectService = createProjectService(host, { useSingleInferredProject: true, typingsInstaller: installer });
+            projectService.openClientFile(file1.path);
+
+            checkNumberOfProjects(projectService, { inferredProjects: 1 });
+            const p = projectService.inferredProjects[0];
+            checkProjectActualFiles(p, [file1.path]);
+
+            installer.installAll([TI.NpmViewRequest], [TI.NpmInstallRequest]);
+
+            checkNumberOfProjects(projectService, { inferredProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, jquery.path]);
+        });
+
+        it("external project - no typing options, no .d.ts/js files", () => {
+            const file1 = {
+                path: "/a/b/app.ts",
+                content: ""
+            };
+            const host = createServerHost([file1]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                enqueueInstallTypingsRequest() {
+                    assert(false, "auto discovery should not be enabled");
+                }
+            })();
+
+            const projectFileName = "/a/app/test.csproj";
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            projectService.openExternalProject({
+                projectFileName,
+                options: {},
+                rootFiles: [toExternalFile(file1.path)]
+            });
+            installer.checkPendingCommands([]);
+            // by default auto discovery will kick in if project contain only .js/.d.ts files
+            // in this case project contain only ts files - no auto discovery
+            projectService.checkNumberOfProjects({ externalProjects: 1 });
+        });
+
+        it("external project - no autoDiscovery in typing options, no .d.ts/js files", () => {
+            const file1 = {
+                path: "/a/b/app.ts",
+                content: ""
+            };
+            const host = createServerHost([file1]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                enqueueInstallTypingsRequest() {
+                    assert(false, "auto discovery should not be enabled");
+                }
+            })();
+
+            const projectFileName = "/a/app/test.csproj";
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            projectService.openExternalProject({
+                projectFileName,
+                options: {},
+                rootFiles: [toExternalFile(file1.path)],
+                typingOptions: { include: ["jquery"] }
+            });
+            installer.checkPendingCommands([]);
+            // by default auto discovery will kick in if project contain only .js/.d.ts files
+            // in this case project contain only ts files - no auto discovery even if typing options is set
+            projectService.checkNumberOfProjects({ externalProjects: 1 });
+        });
+
+        it("external project - autoDiscovery = true, no .d.ts/js files", () => {
+            const file1 = {
+                path: "/a/b/app.ts",
+                content: ""
+            };
+            const jquery = {
+                path: "/a/data/node_modules/@types/jquery/index.d.ts",
+                content: "declare const $: { x: number }"
+            };
+            const host = createServerHost([file1]);
+            let enqueueIsCalled = false;
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                enqueueInstallTypingsRequest(project: server.Project, typingOptions: TypingOptions) {
+                    enqueueIsCalled = true;
+                    super.enqueueInstallTypingsRequest(project, typingOptions);
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: TI.RequestCompletedAction): void {
+                    const installedTypings = ["@types/jquery"];
+                    const typingFiles = [jquery];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectFileName = "/a/app/test.csproj";
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            projectService.openExternalProject({
+                projectFileName,
+                options: {},
+                rootFiles: [toExternalFile(file1.path)],
+                typingOptions: { enableAutoDiscovery: true, include: ["node"] }
+            });
+
+            assert.isTrue(enqueueIsCalled, "expected enqueueIsCalled to be true");
+            installer.installAll([TI.NpmViewRequest], [TI.NpmInstallRequest]);
+
+            // autoDiscovery is set in typing options - use it even if project contains only .ts files
+            projectService.checkNumberOfProjects({ externalProjects: 1 });
+        });
+
+        it("external project - no typing options, with only js, jsx, d.ts files", () => {
+            // Tests:
+            // 1. react typings are installed for .jsx
+            // 2. loose files names are matched against safe list for typings if
+            //    this is a JS project (only js, jsx, d.ts files are present)
+            const file1 = {
+                path: "/a/b/lodash.js",
+                content: ""
+            };
+            const file2 = {
+                path: "/a/b/file2.jsx",
+                content: ""
+            };
+            const file3 = {
+                path: "/a/b/file3.d.ts",
+                content: ""
+            };
+            const react = {
+                path: "/a/data/node_modules/@types/react/index.d.ts",
+                content: "declare const react: { x: number }"
+            };
+            const lodash = {
+                path: "/a/data/node_modules/@types/lodash/index.d.ts",
+                content: "declare const lodash: { x: number }"
+            };
+
+            const host = createServerHost([file1, file2, file3]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: TI.RequestCompletedAction): void {
+                    const installedTypings = ["@types/lodash", "@types/react"];
+                    const typingFiles = [lodash, react];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectFileName = "/a/app/test.csproj";
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            projectService.openExternalProject({
+                projectFileName,
+                options: { allowJS: true, moduleResolution: ModuleResolutionKind.NodeJs },
+                rootFiles: [toExternalFile(file1.path), toExternalFile(file2.path), toExternalFile(file3.path)],
+                typingOptions: {}
+            });
+
+            const p = projectService.externalProjects[0];
+            projectService.checkNumberOfProjects({ externalProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, file2.path, file3.path]);
+
+            installer.installAll([TI.NpmViewRequest, TI.NpmViewRequest], [TI.NpmInstallRequest], );
+
+            checkNumberOfProjects(projectService, { externalProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, file2.path, file3.path, lodash.path, react.path]);
+        });
+
+        it("external project - no typing options, with js & ts files", () => {
+            // Tests:
+            // 1. No typings are included for JS projects when the project contains ts files
+            const file1 = {
+                path: "/a/b/jquery.js",
+                content: ""
+            };
+            const file2 = {
+                path: "/a/b/file2.ts",
+                content: ""
+            };
+
+            const host = createServerHost([file1, file2]);
+            let enqueueIsCalled = false;
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                enqueueInstallTypingsRequest(project: server.Project, typingOptions: TypingOptions) {
+                    enqueueIsCalled = true;
+                    super.enqueueInstallTypingsRequest(project, typingOptions);
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: TI.RequestCompletedAction): void {
+                    const installedTypings: string[] = [];
+                    const typingFiles: FileOrFolder[] = [];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectFileName = "/a/app/test.csproj";
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            projectService.openExternalProject({
+                projectFileName,
+                options: { allowJS: true, moduleResolution: ModuleResolutionKind.NodeJs },
+                rootFiles: [toExternalFile(file1.path), toExternalFile(file2.path)],
+                typingOptions: {}
+            });
+
+            const p = projectService.externalProjects[0];
+            projectService.checkNumberOfProjects({ externalProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, file2.path]);
+
+            installer.checkPendingCommands([]);
+
+            checkNumberOfProjects(projectService, { externalProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, file2.path]);
+        });
+
+        it("external project - with typing options, with only js, d.ts files", () => {
+            // Tests:
+            // 1. Safelist matching, typing options includes/excludes and package.json typings are all acquired
+            // 2. Types for safelist matches are not included when they also appear in the typing option exclude list
+            // 3. Multiple includes and excludes are respected in typing options
+            const file1 = {
+                path: "/a/b/lodash.js",
+                content: ""
+            };
+            const file2 = {
+                path: "/a/b/commander.js",
+                content: ""
+            };
+            const file3 = {
+                path: "/a/b/file3.d.ts",
+                content: ""
+            };
+            const packageJson = {
+                path: "/a/b/package.json",
+                content: JSON.stringify({
+                    name: "test",
+                    dependencies: {
+                        express: "^3.1.0"
+                    }
+                })
+            };
+
+            const commander = {
+                path: "/a/data/node_modules/@types/commander/index.d.ts",
+                content: "declare const commander: { x: number }"
+            };
+            const express = {
+                path: "/a/data/node_modules/@types/express/index.d.ts",
+                content: "declare const express: { x: number }"
+            };
+            const jquery = {
+                path: "/a/data/node_modules/@types/jquery/index.d.ts",
+                content: "declare const jquery: { x: number }"
+            };
+            const moment = {
+                path: "/a/data/node_modules/@types/moment/index.d.ts",
+                content: "declare const moment: { x: number }"
+            };
+
+            const host = createServerHost([file1, file2, file3, packageJson]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host);
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: TI.RequestCompletedAction): void {
+                    const installedTypings = ["@types/commander", "@types/express", "@types/jquery", "@types/moment"];
+                    const typingFiles = [commander, express, jquery, moment];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectFileName = "/a/app/test.csproj";
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            projectService.openExternalProject({
+                projectFileName,
+                options: { allowJS: true, moduleResolution: ModuleResolutionKind.NodeJs },
+                rootFiles: [toExternalFile(file1.path), toExternalFile(file2.path), toExternalFile(file3.path)],
+                typingOptions: { include: ["jquery", "moment"], exclude: ["lodash"] }
+            });
+
+            const p = projectService.externalProjects[0];
+            projectService.checkNumberOfProjects({ externalProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, file2.path, file3.path]);
+
+            installer.installAll(
+                [TI.NpmViewRequest, TI.NpmViewRequest, TI.NpmViewRequest, TI.NpmViewRequest],
+                [TI.NpmInstallRequest]
+            );
+
+            checkNumberOfProjects(projectService, { externalProjects: 1 });
+            checkProjectActualFiles(p, [file1.path, file2.path, file3.path, commander.path, express.path, jquery.path, moment.path]);
+        });
+
+        it("Throttle - delayed typings to install", () => {
+            const lodashJs = {
+                path: "/a/b/lodash.js",
+                content: ""
+            };
+            const commanderJs = {
+                path: "/a/b/commander.js",
+                content: ""
+            };
+            const file3 = {
+                path: "/a/b/file3.d.ts",
+                content: ""
+            };
+            const packageJson = {
+                path: "/a/b/package.json",
+                content: JSON.stringify({
+                    name: "test",
+                    dependencies: {
+                        express: "^3.1.0"
+                    }
+                })
+            };
+
+            const commander = {
+                path: "/a/data/node_modules/@types/commander/index.d.ts",
+                content: "declare const commander: { x: number }"
+            };
+            const express = {
+                path: "/a/data/node_modules/@types/express/index.d.ts",
+                content: "declare const express: { x: number }"
+            };
+            const jquery = {
+                path: "/a/data/node_modules/@types/jquery/index.d.ts",
+                content: "declare const jquery: { x: number }"
+            };
+            const moment = {
+                path: "/a/data/node_modules/@types/moment/index.d.ts",
+                content: "declare const moment: { x: number }"
+            };
+            const lodash = {
+                path: "/a/data/node_modules/@types/lodash/index.d.ts",
+                content: "declare const lodash: { x: number }"
+            };
+
+            const typingFiles = [commander, express, jquery, moment, lodash];
+            const host = createServerHost([lodashJs, commanderJs, file3, packageJson]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host, { throttleLimit: 3 });
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: TI.RequestCompletedAction): void {
+                    const installedTypings = ["@types/commander", "@types/express", "@types/jquery", "@types/moment", "@types/lodash"];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectFileName = "/a/app/test.csproj";
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            projectService.openExternalProject({
+                projectFileName,
+                options: { allowJS: true, moduleResolution: ModuleResolutionKind.NodeJs },
+                rootFiles: [toExternalFile(lodashJs.path), toExternalFile(commanderJs.path), toExternalFile(file3.path)],
+                typingOptions: { include: ["jquery", "moment"] }
+            });
+
+            const p = projectService.externalProjects[0];
+            projectService.checkNumberOfProjects({ externalProjects: 1 });
+            checkProjectActualFiles(p, [lodashJs.path, commanderJs.path, file3.path]);
+            // expected 3 view requests in the queue
+            installer.checkPendingCommands([TI.NpmViewRequest, TI.NpmViewRequest, TI.NpmViewRequest]);
+            assert.equal(installer.pendingRunRequests.length, 2, "expected 2 pending requests");
+
+            // push view requests
+            installer.executePendingCommands();
+            // expected 2 remaining view requests in the queue
+            installer.checkPendingCommands([TI.NpmViewRequest, TI.NpmViewRequest]);
+            // push view requests
+            installer.executePendingCommands();
+            // expected one install request
+            installer.checkPendingCommands([TI.NpmInstallRequest]);
+            installer.executePendingCommands();
+            // expected all typings file to exist
+            for (const f of typingFiles) {
+                assert.isTrue(host.fileExists(f.path), `expected file ${f.path} to exist`);
+            }
+
+            checkNumberOfProjects(projectService, { externalProjects: 1 });
+            checkProjectActualFiles(p, [lodashJs.path, commanderJs.path, file3.path, commander.path, express.path, jquery.path, moment.path, lodash.path]);
+        });
+
+        it("Throttle - delayed run install requests", () => {
+            const lodashJs = {
+                path: "/a/b/lodash.js",
+                content: ""
+            };
+            const commanderJs = {
+                path: "/a/b/commander.js",
+                content: ""
+            };
+            const file3 = {
+                path: "/a/b/file3.d.ts",
+                content: ""
+            };
+
+            const commander = {
+                path: "/a/data/node_modules/@types/commander/index.d.ts",
+                content: "declare const commander: { x: number }",
+                typings: "@types/commander"
+            };
+            const jquery = {
+                path: "/a/data/node_modules/@types/jquery/index.d.ts",
+                content: "declare const jquery: { x: number }",
+                typings: "@types/jquery"
+            };
+            const lodash = {
+                path: "/a/data/node_modules/@types/lodash/index.d.ts",
+                content: "declare const lodash: { x: number }",
+                typings: "@types/lodash"
+            };
+            const cordova = {
+                path: "/a/data/node_modules/@types/cordova/index.d.ts",
+                content: "declare const cordova: { x: number }",
+                typings: "@types/cordova"
+            };
+            const grunt = {
+                path: "/a/data/node_modules/@types/grunt/index.d.ts",
+                content: "declare const grunt: { x: number }",
+                typings: "@types/grunt"
+            };
+            const gulp = {
+                path: "/a/data/node_modules/@types/gulp/index.d.ts",
+                content: "declare const gulp: { x: number }",
+                typings: "@types/gulp"
+            };
+
+            const host = createServerHost([lodashJs, commanderJs, file3]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host, { throttleLimit: 3 });
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: TI.RequestCompletedAction): void {
+                    if (requestKind === TI.NpmInstallRequest) {
+                        let typingFiles: (FileOrFolder & { typings: string}) [] = [];
+                        if (command.indexOf("commander") >= 0) {
+                            typingFiles = [commander, jquery, lodash, cordova];
+                        }
+                        else {
+                            typingFiles = [grunt, gulp];
+                        }
+                        executeCommand(this, host, typingFiles.map(f => f.typings), typingFiles, requestKind, cb);
+                    }
+                    else {
+                        executeCommand(this, host, [], [], requestKind, cb);
+                    }
+                }
+            })();
+
+            // Create project #1 with 4 typings
+            const projectService = createProjectService(host, { typingsInstaller: installer });
+            const projectFileName1 = "/a/app/test1.csproj";
+            projectService.openExternalProject({
+                projectFileName: projectFileName1,
+                options: { allowJS: true, moduleResolution: ModuleResolutionKind.NodeJs },
+                rootFiles: [toExternalFile(lodashJs.path), toExternalFile(commanderJs.path), toExternalFile(file3.path)],
+                typingOptions: { include: ["jquery", "cordova" ] }
+            });
+
+            installer.checkPendingCommands([TI.NpmViewRequest, TI.NpmViewRequest, TI.NpmViewRequest]);
+            assert.equal(installer.pendingRunRequests.length, 1, "expect one throttled request");
+
+            // Create project #2 with 2 typings
+            const projectFileName2 = "/a/app/test2.csproj";
+            projectService.openExternalProject({
+                projectFileName: projectFileName2,
+                options: { allowJS: true, moduleResolution: ModuleResolutionKind.NodeJs },
+                rootFiles: [toExternalFile(file3.path)],
+                typingOptions: { include: ["grunt", "gulp"] }
+            });
+            assert.equal(installer.pendingRunRequests.length, 3, "expect three throttled request");
+
+            const p1 = projectService.externalProjects[0];
+            const p2 = projectService.externalProjects[1];
+            projectService.checkNumberOfProjects({ externalProjects: 2 });
+            checkProjectActualFiles(p1, [lodashJs.path, commanderJs.path, file3.path]);
+            checkProjectActualFiles(p2, [file3.path]);
+
+
+            installer.executePendingCommands();
+            // expected one view request from the first project and two - from the second one
+            installer.checkPendingCommands([TI.NpmViewRequest, TI.NpmViewRequest, TI.NpmViewRequest]);
+            assert.equal(installer.pendingRunRequests.length, 0, "expected no throttled requests");
+
+            installer.executePendingCommands();
+
+            // should be two install requests from both projects
+            installer.checkPendingCommands([TI.NpmInstallRequest, TI.NpmInstallRequest]);
+            installer.executePendingCommands();
+
+            checkProjectActualFiles(p1, [lodashJs.path, commanderJs.path, file3.path, commander.path, jquery.path, lodash.path, cordova.path]);
+            checkProjectActualFiles(p2, [file3.path, grunt.path, gulp.path ]);
+        });
+
+        it("configured projects discover from node_modules", () => {
+            const app = {
+                path: "/app.js",
+                content: ""
+            };
+            const jsconfig = {
+                path: "/jsconfig.json",
+                content: JSON.stringify({})
+            };
+            const jquery = {
+                path: "/node_modules/jquery/index.js",
+                content: ""
+            };
+            const jqueryPackage = {
+                path: "/node_modules/jquery/package.json",
+                content: JSON.stringify({ name: "jquery" })
+            };
+            const jqueryDTS = {
+                path: "/tmp/node_modules/@types/jquery/index.d.ts",
+                content: ""
+            };
+            const host = createServerHost([app, jsconfig, jquery, jqueryPackage]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host, { globalTypingsCacheLocation: "/tmp" });
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                    const installedTypings = ["@types/jquery"];
+                    const typingFiles = [jqueryDTS];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectService = createProjectService(host, { useSingleInferredProject: true, typingsInstaller: installer });
+            projectService.openClientFile(app.path);
+
+            checkNumberOfProjects(projectService, { configuredProjects: 1 });
+            const p = projectService.configuredProjects[0];
+            checkProjectActualFiles(p, [app.path]);
+
+            installer.installAll([TI.NpmViewRequest], [TI.NpmInstallRequest]);
+
+            checkNumberOfProjects(projectService, { configuredProjects: 1 });
+            checkProjectActualFiles(p, [app.path, jqueryDTS.path]);
+        });
+
+        it("configured projects discover from bower.josn", () => {
+            const app = {
+                path: "/app.js",
+                content: ""
+            };
+            const jsconfig = {
+                path: "/jsconfig.json",
+                content: JSON.stringify({})
+            };
+            const bowerJson = {
+                path: "/bower.json",
+                content: JSON.stringify({
+                        "dependencies": {
+                            "jquery": "^3.1.0"
+                        }
+                    })
+            };
+            const jqueryDTS = {
+                path: "/tmp/node_modules/@types/jquery/index.d.ts",
+                content: ""
+            };
+            const host = createServerHost([app, jsconfig, bowerJson]);
+            const installer = new (class extends Installer {
+                constructor() {
+                    super(host, { globalTypingsCacheLocation: "/tmp" });
+                }
+                runCommand(requestKind: TI.RequestKind, requestId: number, command: string, cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                    const installedTypings = ["@types/jquery"];
+                    const typingFiles = [jqueryDTS];
+                    executeCommand(this, host, installedTypings, typingFiles, requestKind, cb);
+                }
+            })();
+
+            const projectService = createProjectService(host, { useSingleInferredProject: true, typingsInstaller: installer });
+            projectService.openClientFile(app.path);
+
+            checkNumberOfProjects(projectService, { configuredProjects: 1 });
+            const p = projectService.configuredProjects[0];
+            checkProjectActualFiles(p, [app.path]);
+
+            installer.installAll([TI.NpmViewRequest], [TI.NpmInstallRequest]);
+
+            checkNumberOfProjects(projectService, { configuredProjects: 1 });
+            checkProjectActualFiles(p, [app.path, jqueryDTS.path]);
+        });
+    });
+}

src/harness/virtualFileSystem.ts

@@ -10,13 +10,13 @@ namespace Utils {
             this.name = name;
         }
 
-        isDirectory() { return false; }
-        isFile() { return false; }
-        isFileSystem() { return false; }
+        isDirectory(): this is VirtualDirectory { return false; }
+        isFile(): this is VirtualFile { return false; }
+        isFileSystem(): this is VirtualFileSystem { return false; }
     }
 
     export class VirtualFile extends VirtualFileSystemEntry {
-        content: string;
+        content?: Harness.LanguageService.ScriptInfo;
         isFile() { return true; }
     }
 
@@ -73,7 +73,7 @@ namespace Utils {
             }
         }
 
-        addFile(name: string, content?: string): VirtualFile {
+        addFile(name: string, content?: Harness.LanguageService.ScriptInfo): VirtualFile {
             const entry = this.getFileSystemEntry(name);
             if (entry === undefined) {
                 const file = new VirtualFile(this.fileSystem, name);
@@ -82,9 +82,8 @@ namespace Utils {
                 return file;
             }
             else if (entry.isFile()) {
-                const file = <VirtualFile>entry;
-                file.content = content;
-                return file;
+                entry.content = content;
+                return entry;
             }
             else {
                 return undefined;
@@ -111,6 +110,7 @@ namespace Utils {
         getFileSystemEntries() { return this.root.getFileSystemEntries(); }
 
         addDirectory(path: string) {
+            path = ts.normalizePath(path);
             const components = ts.getNormalizedPathComponents(path, this.currentDirectory);
             let directory: VirtualDirectory = this.root;
             for (const component of components) {
@@ -123,8 +123,8 @@ namespace Utils {
             return directory;
         }
 
-        addFile(path: string, content?: string) {
-            const absolutePath = ts.getNormalizedAbsolutePath(path, this.currentDirectory);
+        addFile(path: string, content?: Harness.LanguageService.ScriptInfo) {
+            const absolutePath = ts.normalizePath(ts.getNormalizedAbsolutePath(path, this.currentDirectory));
             const fileName = ts.getBaseFileName(path);
             const directoryPath = ts.getDirectoryPath(absolutePath);
             const directory = this.addDirectory(directoryPath);
@@ -141,6 +141,7 @@ namespace Utils {
         }
 
         traversePath(path: string) {
+            path = ts.normalizePath(path);
             let directory: VirtualDirectory = this.root;
             for (const component of ts.getNormalizedPathComponents(path, this.currentDirectory)) {
                 const entry = directory.getFileSystemEntry(component);
@@ -157,20 +158,12 @@ namespace Utils {
 
             return directory;
         }
-    }
-
-    export class MockParseConfigHost extends VirtualFileSystem implements ts.ParseConfigHost {
-        constructor(currentDirectory: string, ignoreCase: boolean, files: string[]) {
-            super(currentDirectory, ignoreCase);
-            for (const file of files) {
-                this.addFile(file);
-            }
-        }
-
-        readDirectory(path: string, extensions: string[], excludes: string[], includes: string[]) {
-            return ts.matchFiles(path, extensions, excludes, includes, this.useCaseSensitiveFileNames, this.currentDirectory, (path: string) => this.getAccessibleFileSystemEntries(path));
-        }
 
+        /**
+         * Reads the directory at the given path and retrieves a list of file names and a list
+         * of directory names within it. Suitable for use with ts.matchFiles()
+         * @param path  The path to the directory to be read
+         */
         getAccessibleFileSystemEntries(path: string) {
             const entry = this.traversePath(path);
             if (entry && entry.isDirectory()) {
@@ -182,5 +175,43 @@ namespace Utils {
             }
             return { files: [], directories: [] };
         }
+
+        getAllFileEntries() {
+            const fileEntries: VirtualFile[] = [];
+            getFilesRecursive(this.root, fileEntries);
+            return fileEntries;
+
+            function getFilesRecursive(dir: VirtualDirectory, result: VirtualFile[]) {
+                const files = dir.getFiles();
+                const dirs = dir.getDirectories();
+                for (const file of files) {
+                    result.push(file);
+                }
+                for (const subDir of dirs) {
+                    getFilesRecursive(subDir, result);
+                }
+            }
+        }
+    }
+
+    export class MockParseConfigHost extends VirtualFileSystem implements ts.ParseConfigHost {
+        constructor(currentDirectory: string, ignoreCase: boolean, files: ts.MapLike<string> | string[]) {
+            super(currentDirectory, ignoreCase);
+            const fileNames = (files instanceof Array) ? files : ts.getOwnKeys(files);
+            for (const file of fileNames) {
+                this.addFile(file, new  Harness.LanguageService.ScriptInfo(file, (files as ts.MapLike<string>)[file], /*isRootFile*/false));
+            }
+        }
+
+        readFile(path: string): string {
+            const value = this.traversePath(path);
+            if (value && value.isFile()) {
+                return value.content.content;
+            }
+        }
+
+        readDirectory(path: string, extensions: string[], excludes: string[], includes: string[]) {
+            return ts.matchFiles(path, extensions, excludes, includes, this.useCaseSensitiveFileNames, this.currentDirectory, (path: string) => this.getAccessibleFileSystemEntries(path));
+        }
     }
 }

src/lib/dom.generated.d.ts

@@ -126,6 +126,7 @@ interface KeyAlgorithm {
 }
 
 interface KeyboardEventInit extends EventModifierInit {
+    code?: string;
     key?: string;
     location?: number;
     repeat?: boolean;
@@ -2288,7 +2289,7 @@ declare var DeviceRotationRate: {
     new(): DeviceRotationRate;
 }
 
-interface Document extends Node, GlobalEventHandlers, NodeSelector, DocumentEvent {
+interface Document extends Node, GlobalEventHandlers, NodeSelector, DocumentEvent, ParentNode {
     /**
       * Sets or gets the URL for the current document. 
       */
@@ -3351,7 +3352,7 @@ declare var Document: {
     new(): Document;
 }
 
-interface DocumentFragment extends Node, NodeSelector {
+interface DocumentFragment extends Node, NodeSelector, ParentNode {
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, useCapture?: boolean): void;
 }
 
@@ -3420,7 +3421,7 @@ declare var EXT_texture_filter_anisotropic: {
     readonly TEXTURE_MAX_ANISOTROPY_EXT: number;
 }
 
-interface Element extends Node, GlobalEventHandlers, ElementTraversal, NodeSelector, ChildNode {
+interface Element extends Node, GlobalEventHandlers, ElementTraversal, NodeSelector, ChildNode, ParentNode {
     readonly classList: DOMTokenList;
     className: string;
     readonly clientHeight: number;
@@ -3675,6 +3676,16 @@ interface Element extends Node, GlobalEventHandlers, ElementTraversal, NodeSelec
     getElementsByClassName(classNames: string): NodeListOf<Element>;
     matches(selector: string): boolean;
     closest(selector: string): Element | null;
+    scrollIntoView(arg?: boolean | ScrollIntoViewOptions): void;
+    scroll(options?: ScrollToOptions): void;
+    scroll(x: number, y: number): void;
+    scrollTo(options?: ScrollToOptions): void;
+    scrollTo(x: number, y: number): void;
+    scrollBy(options?: ScrollToOptions): void;
+    scrollBy(x: number, y: number): void;
+    insertAdjacentElement(position: string, insertedElement: Element): Element | null;
+    insertAdjacentHTML(where: string, html: string): void;
+    insertAdjacentText(where: string, text: string): void;
     addEventListener(type: "MSGestureChange", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "MSGestureDoubleTap", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "MSGestureEnd", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
@@ -4446,7 +4457,7 @@ interface HTMLCanvasElement extends HTMLElement {
       * @param type The standard MIME type for the image format to return. If you do not specify this parameter, the default value is a PNG format image.
       */
     toDataURL(type?: string, ...args: any[]): string;
-    toBlob(callback: (result: Blob | null) => void, ... arguments: any[]): void;
+    toBlob(callback: (result: Blob | null) => void, type?: string, ...arguments: any[]): void;
 }
 
 declare var HTMLCanvasElement: {
@@ -4621,11 +4632,7 @@ interface HTMLElement extends Element {
     click(): void;
     dragDrop(): boolean;
     focus(): void;
-    insertAdjacentElement(position: string, insertedElement: Element): Element;
-    insertAdjacentHTML(where: string, html: string): void;
-    insertAdjacentText(where: string, text: string): void;
     msGetInputContext(): MSInputMethodContext;
-    scrollIntoView(top?: boolean): void;
     setActive(): void;
     addEventListener(type: "MSContentZoom", listener: (this: this, ev: UIEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "MSGestureChange", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
@@ -5890,6 +5897,7 @@ interface HTMLLinkElement extends HTMLElement, LinkStyle {
       */
     type: string;
     import?: Document;
+    integrity: string;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, useCapture?: boolean): void;
 }
 
@@ -6178,7 +6186,7 @@ interface HTMLMediaElement extends HTMLElement {
       */
     canPlayType(type: string): string;
     /**
-      * Fires immediately after the client loads the object.
+      * Resets the audio or video object and loads a new media resource.
       */
     load(): void;
     /**
@@ -6751,6 +6759,7 @@ interface HTMLScriptElement extends HTMLElement {
       * Sets or retrieves the MIME type for the associated scripting engine.
       */
     type: string;
+    integrity: string;
 }
 
 declare var HTMLScriptElement: {
@@ -7527,11 +7536,12 @@ declare var HashChangeEvent: {
 interface History {
     readonly length: number;
     readonly state: any;
-    back(distance?: any): void;
-    forward(distance?: any): void;
-    go(delta?: any): void;
-    pushState(statedata: any, title?: string, url?: string): void;
-    replaceState(statedata: any, title?: string, url?: string): void;
+    scrollRestoration: ScrollRestoration;
+    back(): void;
+    forward(): void;
+    go(delta?: number): void;
+    pushState(data: any, title: string, url?: string | null): void;
+    replaceState(data: any, title: string, url?: string | null): void;
 }
 
 declare var History: {
@@ -7756,6 +7766,7 @@ interface KeyboardEvent extends UIEvent {
     readonly repeat: boolean;
     readonly shiftKey: boolean;
     readonly which: number;
+    readonly code: string;
     getModifierState(keyArg: string): boolean;
     initKeyboardEvent(typeArg: string, canBubbleArg: boolean, cancelableArg: boolean, viewArg: Window, keyArg: string, locationArg: number, modifiersListArg: string, repeat: boolean, locale: string): void;
     readonly DOM_KEY_LOCATION_JOYSTICK: number;
@@ -9128,6 +9139,7 @@ interface PerformanceTiming {
     readonly responseStart: number;
     readonly unloadEventEnd: number;
     readonly unloadEventStart: number;
+    readonly secureConnectionStart: number;
     toJSON(): any;
 }
 
@@ -11405,8 +11417,8 @@ declare var StereoPannerNode: {
 interface Storage {
     readonly length: number;
     clear(): void;
-    getItem(key: string): string;
-    key(index: number): string;
+    getItem(key: string): string | null;
+    key(index: number): string | null;
     removeItem(key: string): void;
     setItem(key: string, data: string): void;
     [key: string]: any;
@@ -12947,7 +12959,7 @@ interface Window extends EventTarget, WindowTimers, WindowSessionStorage, Window
     onunload: (this: this, ev: Event) => any;
     onvolumechange: (this: this, ev: Event) => any;
     onwaiting: (this: this, ev: Event) => any;
-    readonly opener: Window;
+    opener: any;
     orientation: string | number;
     readonly outerHeight: number;
     readonly outerWidth: number;
@@ -13002,6 +13014,9 @@ interface Window extends EventTarget, WindowTimers, WindowSessionStorage, Window
     webkitConvertPointFromNodeToPage(node: Node, pt: WebKitPoint): WebKitPoint;
     webkitConvertPointFromPageToNode(node: Node, pt: WebKitPoint): WebKitPoint;
     webkitRequestAnimationFrame(callback: FrameRequestCallback): number;
+    scroll(options?: ScrollToOptions): void;
+    scrollTo(options?: ScrollToOptions): void;
+    scrollBy(options?: ScrollToOptions): void;
     addEventListener(type: "MSGestureChange", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "MSGestureDoubleTap", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "MSGestureEnd", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
@@ -13098,7 +13113,6 @@ interface Window extends EventTarget, WindowTimers, WindowSessionStorage, Window
     addEventListener(type: "waiting", listener: (this: this, ev: Event) => any, useCapture?: boolean): void;
     addEventListener(type: "wheel", listener: (this: this, ev: WheelEvent) => any, useCapture?: boolean): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, useCapture?: boolean): void;
-    [index: number]: Window;
 }
 
 declare var Window: {
@@ -13129,7 +13143,7 @@ declare var XMLDocument: {
 }
 
 interface XMLHttpRequest extends EventTarget, XMLHttpRequestEventTarget {
-    onreadystatechange: (this: this, ev: ProgressEvent) => any;
+    onreadystatechange: (this: this, ev: Event) => any;
     readonly readyState: number;
     readonly response: any;
     readonly responseText: string;
@@ -13156,13 +13170,13 @@ interface XMLHttpRequest extends EventTarget, XMLHttpRequestEventTarget {
     readonly LOADING: number;
     readonly OPENED: number;
     readonly UNSENT: number;
-    addEventListener(type: "abort", listener: (this: this, ev: Event) => any, useCapture?: boolean): void;
-    addEventListener(type: "error", listener: (this: this, ev: ErrorEvent) => any, useCapture?: boolean): void;
-    addEventListener(type: "load", listener: (this: this, ev: Event) => any, useCapture?: boolean): void;
+    addEventListener(type: "abort", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
+    addEventListener(type: "error", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
+    addEventListener(type: "load", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "loadend", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
-    addEventListener(type: "loadstart", listener: (this: this, ev: Event) => any, useCapture?: boolean): void;
+    addEventListener(type: "loadstart", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "progress", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
-    addEventListener(type: "readystatechange", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
+    addEventListener(type: "readystatechange", listener: (this: this, ev: Event) => any, useCapture?: boolean): void;
     addEventListener(type: "timeout", listener: (this: this, ev: ProgressEvent) => any, useCapture?: boolean): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, useCapture?: boolean): void;
 }
@@ -13503,183 +13517,183 @@ interface NavigatorUserMedia {
 }
 
 interface NodeSelector {
-    querySelector(selectors: "a"): HTMLAnchorElement;
-    querySelector(selectors: "abbr"): HTMLElement;
-    querySelector(selectors: "acronym"): HTMLElement;
-    querySelector(selectors: "address"): HTMLElement;
-    querySelector(selectors: "applet"): HTMLAppletElement;
-    querySelector(selectors: "area"): HTMLAreaElement;
-    querySelector(selectors: "article"): HTMLElement;
-    querySelector(selectors: "aside"): HTMLElement;
-    querySelector(selectors: "audio"): HTMLAudioElement;
-    querySelector(selectors: "b"): HTMLElement;
-    querySelector(selectors: "base"): HTMLBaseElement;
-    querySelector(selectors: "basefont"): HTMLBaseFontElement;
-    querySelector(selectors: "bdo"): HTMLElement;
-    querySelector(selectors: "big"): HTMLElement;
-    querySelector(selectors: "blockquote"): HTMLQuoteElement;
-    querySelector(selectors: "body"): HTMLBodyElement;
-    querySelector(selectors: "br"): HTMLBRElement;
-    querySelector(selectors: "button"): HTMLButtonElement;
-    querySelector(selectors: "canvas"): HTMLCanvasElement;
-    querySelector(selectors: "caption"): HTMLTableCaptionElement;
-    querySelector(selectors: "center"): HTMLElement;
-    querySelector(selectors: "circle"): SVGCircleElement;
-    querySelector(selectors: "cite"): HTMLElement;
-    querySelector(selectors: "clippath"): SVGClipPathElement;
-    querySelector(selectors: "code"): HTMLElement;
-    querySelector(selectors: "col"): HTMLTableColElement;
-    querySelector(selectors: "colgroup"): HTMLTableColElement;
-    querySelector(selectors: "datalist"): HTMLDataListElement;
-    querySelector(selectors: "dd"): HTMLElement;
-    querySelector(selectors: "defs"): SVGDefsElement;
-    querySelector(selectors: "del"): HTMLModElement;
-    querySelector(selectors: "desc"): SVGDescElement;
-    querySelector(selectors: "dfn"): HTMLElement;
-    querySelector(selectors: "dir"): HTMLDirectoryElement;
-    querySelector(selectors: "div"): HTMLDivElement;
-    querySelector(selectors: "dl"): HTMLDListElement;
-    querySelector(selectors: "dt"): HTMLElement;
-    querySelector(selectors: "ellipse"): SVGEllipseElement;
-    querySelector(selectors: "em"): HTMLElement;
-    querySelector(selectors: "embed"): HTMLEmbedElement;
-    querySelector(selectors: "feblend"): SVGFEBlendElement;
-    querySelector(selectors: "fecolormatrix"): SVGFEColorMatrixElement;
-    querySelector(selectors: "fecomponenttransfer"): SVGFEComponentTransferElement;
-    querySelector(selectors: "fecomposite"): SVGFECompositeElement;
-    querySelector(selectors: "feconvolvematrix"): SVGFEConvolveMatrixElement;
-    querySelector(selectors: "fediffuselighting"): SVGFEDiffuseLightingElement;
-    querySelector(selectors: "fedisplacementmap"): SVGFEDisplacementMapElement;
-    querySelector(selectors: "fedistantlight"): SVGFEDistantLightElement;
-    querySelector(selectors: "feflood"): SVGFEFloodElement;
-    querySelector(selectors: "fefunca"): SVGFEFuncAElement;
-    querySelector(selectors: "fefuncb"): SVGFEFuncBElement;
-    querySelector(selectors: "fefuncg"): SVGFEFuncGElement;
-    querySelector(selectors: "fefuncr"): SVGFEFuncRElement;
-    querySelector(selectors: "fegaussianblur"): SVGFEGaussianBlurElement;
-    querySelector(selectors: "feimage"): SVGFEImageElement;
-    querySelector(selectors: "femerge"): SVGFEMergeElement;
-    querySelector(selectors: "femergenode"): SVGFEMergeNodeElement;
-    querySelector(selectors: "femorphology"): SVGFEMorphologyElement;
-    querySelector(selectors: "feoffset"): SVGFEOffsetElement;
-    querySelector(selectors: "fepointlight"): SVGFEPointLightElement;
-    querySelector(selectors: "fespecularlighting"): SVGFESpecularLightingElement;
-    querySelector(selectors: "fespotlight"): SVGFESpotLightElement;
-    querySelector(selectors: "fetile"): SVGFETileElement;
-    querySelector(selectors: "feturbulence"): SVGFETurbulenceElement;
-    querySelector(selectors: "fieldset"): HTMLFieldSetElement;
-    querySelector(selectors: "figcaption"): HTMLElement;
-    querySelector(selectors: "figure"): HTMLElement;
-    querySelector(selectors: "filter"): SVGFilterElement;
-    querySelector(selectors: "font"): HTMLFontElement;
-    querySelector(selectors: "footer"): HTMLElement;
-    querySelector(selectors: "foreignobject"): SVGForeignObjectElement;
-    querySelector(selectors: "form"): HTMLFormElement;
-    querySelector(selectors: "frame"): HTMLFrameElement;
-    querySelector(selectors: "frameset"): HTMLFrameSetElement;
-    querySelector(selectors: "g"): SVGGElement;
-    querySelector(selectors: "h1"): HTMLHeadingElement;
-    querySelector(selectors: "h2"): HTMLHeadingElement;
-    querySelector(selectors: "h3"): HTMLHeadingElement;
-    querySelector(selectors: "h4"): HTMLHeadingElement;
-    querySelector(selectors: "h5"): HTMLHeadingElement;
-    querySelector(selectors: "h6"): HTMLHeadingElement;
-    querySelector(selectors: "head"): HTMLHeadElement;
-    querySelector(selectors: "header"): HTMLElement;
-    querySelector(selectors: "hgroup"): HTMLElement;
-    querySelector(selectors: "hr"): HTMLHRElement;
-    querySelector(selectors: "html"): HTMLHtmlElement;
-    querySelector(selectors: "i"): HTMLElement;
-    querySelector(selectors: "iframe"): HTMLIFrameElement;
-    querySelector(selectors: "image"): SVGImageElement;
-    querySelector(selectors: "img"): HTMLImageElement;
-    querySelector(selectors: "input"): HTMLInputElement;
-    querySelector(selectors: "ins"): HTMLModElement;
-    querySelector(selectors: "isindex"): HTMLUnknownElement;
-    querySelector(selectors: "kbd"): HTMLElement;
-    querySelector(selectors: "keygen"): HTMLElement;
-    querySelector(selectors: "label"): HTMLLabelElement;
-    querySelector(selectors: "legend"): HTMLLegendElement;
-    querySelector(selectors: "li"): HTMLLIElement;
-    querySelector(selectors: "line"): SVGLineElement;
-    querySelector(selectors: "lineargradient"): SVGLinearGradientElement;
-    querySelector(selectors: "link"): HTMLLinkElement;
-    querySelector(selectors: "listing"): HTMLPreElement;
-    querySelector(selectors: "map"): HTMLMapElement;
-    querySelector(selectors: "mark"): HTMLElement;
-    querySelector(selectors: "marker"): SVGMarkerElement;
-    querySelector(selectors: "marquee"): HTMLMarqueeElement;
-    querySelector(selectors: "mask"): SVGMaskElement;
-    querySelector(selectors: "menu"): HTMLMenuElement;
-    querySelector(selectors: "meta"): HTMLMetaElement;
-    querySelector(selectors: "metadata"): SVGMetadataElement;
-    querySelector(selectors: "meter"): HTMLMeterElement;
-    querySelector(selectors: "nav"): HTMLElement;
-    querySelector(selectors: "nextid"): HTMLUnknownElement;
-    querySelector(selectors: "nobr"): HTMLElement;
-    querySelector(selectors: "noframes"): HTMLElement;
-    querySelector(selectors: "noscript"): HTMLElement;
-    querySelector(selectors: "object"): HTMLObjectElement;
-    querySelector(selectors: "ol"): HTMLOListElement;
-    querySelector(selectors: "optgroup"): HTMLOptGroupElement;
-    querySelector(selectors: "option"): HTMLOptionElement;
-    querySelector(selectors: "p"): HTMLParagraphElement;
-    querySelector(selectors: "param"): HTMLParamElement;
-    querySelector(selectors: "path"): SVGPathElement;
-    querySelector(selectors: "pattern"): SVGPatternElement;
-    querySelector(selectors: "picture"): HTMLPictureElement;
-    querySelector(selectors: "plaintext"): HTMLElement;
-    querySelector(selectors: "polygon"): SVGPolygonElement;
-    querySelector(selectors: "polyline"): SVGPolylineElement;
-    querySelector(selectors: "pre"): HTMLPreElement;
-    querySelector(selectors: "progress"): HTMLProgressElement;
-    querySelector(selectors: "q"): HTMLQuoteElement;
-    querySelector(selectors: "radialgradient"): SVGRadialGradientElement;
-    querySelector(selectors: "rect"): SVGRectElement;
-    querySelector(selectors: "rt"): HTMLElement;
-    querySelector(selectors: "ruby"): HTMLElement;
-    querySelector(selectors: "s"): HTMLElement;
-    querySelector(selectors: "samp"): HTMLElement;
-    querySelector(selectors: "script"): HTMLScriptElement;
-    querySelector(selectors: "section"): HTMLElement;
-    querySelector(selectors: "select"): HTMLSelectElement;
-    querySelector(selectors: "small"): HTMLElement;
-    querySelector(selectors: "source"): HTMLSourceElement;
-    querySelector(selectors: "span"): HTMLSpanElement;
-    querySelector(selectors: "stop"): SVGStopElement;
-    querySelector(selectors: "strike"): HTMLElement;
-    querySelector(selectors: "strong"): HTMLElement;
-    querySelector(selectors: "style"): HTMLStyleElement;
-    querySelector(selectors: "sub"): HTMLElement;
-    querySelector(selectors: "sup"): HTMLElement;
-    querySelector(selectors: "svg"): SVGSVGElement;
-    querySelector(selectors: "switch"): SVGSwitchElement;
-    querySelector(selectors: "symbol"): SVGSymbolElement;
-    querySelector(selectors: "table"): HTMLTableElement;
-    querySelector(selectors: "tbody"): HTMLTableSectionElement;
-    querySelector(selectors: "td"): HTMLTableDataCellElement;
-    querySelector(selectors: "template"): HTMLTemplateElement;
-    querySelector(selectors: "text"): SVGTextElement;
-    querySelector(selectors: "textpath"): SVGTextPathElement;
-    querySelector(selectors: "textarea"): HTMLTextAreaElement;
-    querySelector(selectors: "tfoot"): HTMLTableSectionElement;
-    querySelector(selectors: "th"): HTMLTableHeaderCellElement;
-    querySelector(selectors: "thead"): HTMLTableSectionElement;
-    querySelector(selectors: "title"): HTMLTitleElement;
-    querySelector(selectors: "tr"): HTMLTableRowElement;
-    querySelector(selectors: "track"): HTMLTrackElement;
-    querySelector(selectors: "tspan"): SVGTSpanElement;
-    querySelector(selectors: "tt"): HTMLElement;
-    querySelector(selectors: "u"): HTMLElement;
-    querySelector(selectors: "ul"): HTMLUListElement;
-    querySelector(selectors: "use"): SVGUseElement;
-    querySelector(selectors: "var"): HTMLElement;
-    querySelector(selectors: "video"): HTMLVideoElement;
-    querySelector(selectors: "view"): SVGViewElement;
-    querySelector(selectors: "wbr"): HTMLElement;
-    querySelector(selectors: "x-ms-webview"): MSHTMLWebViewElement;
-    querySelector(selectors: "xmp"): HTMLPreElement;
-    querySelector(selectors: string): Element;
+    querySelector(selectors: "a"): HTMLAnchorElement | null;
+    querySelector(selectors: "abbr"): HTMLElement | null;
+    querySelector(selectors: "acronym"): HTMLElement | null;
+    querySelector(selectors: "address"): HTMLElement | null;
+    querySelector(selectors: "applet"): HTMLAppletElement | null;
+    querySelector(selectors: "area"): HTMLAreaElement | null;
+    querySelector(selectors: "article"): HTMLElement | null;
+    querySelector(selectors: "aside"): HTMLElement | null;
+    querySelector(selectors: "audio"): HTMLAudioElement | null;
+    querySelector(selectors: "b"): HTMLElement | null;
+    querySelector(selectors: "base"): HTMLBaseElement | null;
+    querySelector(selectors: "basefont"): HTMLBaseFontElement | null;
+    querySelector(selectors: "bdo"): HTMLElement | null;
+    querySelector(selectors: "big"): HTMLElement | null;
+    querySelector(selectors: "blockquote"): HTMLQuoteElement | null;
+    querySelector(selectors: "body"): HTMLBodyElement | null;
+    querySelector(selectors: "br"): HTMLBRElement | null;
+    querySelector(selectors: "button"): HTMLButtonElement | null;
+    querySelector(selectors: "canvas"): HTMLCanvasElement | null;
+    querySelector(selectors: "caption"): HTMLTableCaptionElement | null;
+    querySelector(selectors: "center"): HTMLElement | null;
+    querySelector(selectors: "circle"): SVGCircleElement | null;
+    querySelector(selectors: "cite"): HTMLElement | null;
+    querySelector(selectors: "clippath"): SVGClipPathElement | null;
+    querySelector(selectors: "code"): HTMLElement | null;
+    querySelector(selectors: "col"): HTMLTableColElement | null;
+    querySelector(selectors: "colgroup"): HTMLTableColElement | null;
+    querySelector(selectors: "datalist"): HTMLDataListElement | null;
+    querySelector(selectors: "dd"): HTMLElement | null;
+    querySelector(selectors: "defs"): SVGDefsElement | null;
+    querySelector(selectors: "del"): HTMLModElement | null;
+    querySelector(selectors: "desc"): SVGDescElement | null;
+    querySelector(selectors: "dfn"): HTMLElement | null;
+    querySelector(selectors: "dir"): HTMLDirectoryElement | null;
+    querySelector(selectors: "div"): HTMLDivElement | null;
+    querySelector(selectors: "dl"): HTMLDListElement | null;
+    querySelector(selectors: "dt"): HTMLElement | null;
+    querySelector(selectors: "ellipse"): SVGEllipseElement | null;
+    querySelector(selectors: "em"): HTMLElement | null;
+    querySelector(selectors: "embed"): HTMLEmbedElement | null;
+    querySelector(selectors: "feblend"): SVGFEBlendElement | null;
+    querySelector(selectors: "fecolormatrix"): SVGFEColorMatrixElement | null;
+    querySelector(selectors: "fecomponenttransfer"): SVGFEComponentTransferElement | null;
+    querySelector(selectors: "fecomposite"): SVGFECompositeElement | null;
+    querySelector(selectors: "feconvolvematrix"): SVGFEConvolveMatrixElement | null;
+    querySelector(selectors: "fediffuselighting"): SVGFEDiffuseLightingElement | null;
+    querySelector(selectors: "fedisplacementmap"): SVGFEDisplacementMapElement | null;
+    querySelector(selectors: "fedistantlight"): SVGFEDistantLightElement | null;
+    querySelector(selectors: "feflood"): SVGFEFloodElement | null;
+    querySelector(selectors: "fefunca"): SVGFEFuncAElement | null;
+    querySelector(selectors: "fefuncb"): SVGFEFuncBElement | null;
+    querySelector(selectors: "fefuncg"): SVGFEFuncGElement | null;
+    querySelector(selectors: "fefuncr"): SVGFEFuncRElement | null;
+    querySelector(selectors: "fegaussianblur"): SVGFEGaussianBlurElement | null;
+    querySelector(selectors: "feimage"): SVGFEImageElement | null;
+    querySelector(selectors: "femerge"): SVGFEMergeElement | null;
+    querySelector(selectors: "femergenode"): SVGFEMergeNodeElement | null;
+    querySelector(selectors: "femorphology"): SVGFEMorphologyElement | null;
+    querySelector(selectors: "feoffset"): SVGFEOffsetElement | null;
+    querySelector(selectors: "fepointlight"): SVGFEPointLightElement | null;
+    querySelector(selectors: "fespecularlighting"): SVGFESpecularLightingElement | null;
+    querySelector(selectors: "fespotlight"): SVGFESpotLightElement | null;
+    querySelector(selectors: "fetile"): SVGFETileElement | null;
+    querySelector(selectors: "feturbulence"): SVGFETurbulenceElement | null;
+    querySelector(selectors: "fieldset"): HTMLFieldSetElement | null;
+    querySelector(selectors: "figcaption"): HTMLElement | null;
+    querySelector(selectors: "figure"): HTMLElement | null;
+    querySelector(selectors: "filter"): SVGFilterElement | null;
+    querySelector(selectors: "font"): HTMLFontElement | null;
+    querySelector(selectors: "footer"): HTMLElement | null;
+    querySelector(selectors: "foreignobject"): SVGForeignObjectElement | null;
+    querySelector(selectors: "form"): HTMLFormElement | null;
+    querySelector(selectors: "frame"): HTMLFrameElement | null;
+    querySelector(selectors: "frameset"): HTMLFrameSetElement | null;
+    querySelector(selectors: "g"): SVGGElement | null;
+    querySelector(selectors: "h1"): HTMLHeadingElement | null;
+    querySelector(selectors: "h2"): HTMLHeadingElement | null;
+    querySelector(selectors: "h3"): HTMLHeadingElement | null;
+    querySelector(selectors: "h4"): HTMLHeadingElement | null;
+    querySelector(selectors: "h5"): HTMLHeadingElement | null;
+    querySelector(selectors: "h6"): HTMLHeadingElement | null;
+    querySelector(selectors: "head"): HTMLHeadElement | null;
+    querySelector(selectors: "header"): HTMLElement | null;
+    querySelector(selectors: "hgroup"): HTMLElement | null;
+    querySelector(selectors: "hr"): HTMLHRElement | null;
+    querySelector(selectors: "html"): HTMLHtmlElement | null;
+    querySelector(selectors: "i"): HTMLElement | null;
+    querySelector(selectors: "iframe"): HTMLIFrameElement | null;
+    querySelector(selectors: "image"): SVGImageElement | null;
+    querySelector(selectors: "img"): HTMLImageElement | null;
+    querySelector(selectors: "input"): HTMLInputElement | null;
+    querySelector(selectors: "ins"): HTMLModElement | null;
+    querySelector(selectors: "isindex"): HTMLUnknownElement | null;
+    querySelector(selectors: "kbd"): HTMLElement | null;
+    querySelector(selectors: "keygen"): HTMLElement | null;
+    querySelector(selectors: "label"): HTMLLabelElement | null;
+    querySelector(selectors: "legend"): HTMLLegendElement | null;
+    querySelector(selectors: "li"): HTMLLIElement | null;
+    querySelector(selectors: "line"): SVGLineElement | null;
+    querySelector(selectors: "lineargradient"): SVGLinearGradientElement | null;
+    querySelector(selectors: "link"): HTMLLinkElement | null;
+    querySelector(selectors: "listing"): HTMLPreElement | null;
+    querySelector(selectors: "map"): HTMLMapElement | null;
+    querySelector(selectors: "mark"): HTMLElement | null;
+    querySelector(selectors: "marker"): SVGMarkerElement | null;
+    querySelector(selectors: "marquee"): HTMLMarqueeElement | null;
+    querySelector(selectors: "mask"): SVGMaskElement | null;
+    querySelector(selectors: "menu"): HTMLMenuElement | null;
+    querySelector(selectors: "meta"): HTMLMetaElement | null;
+    querySelector(selectors: "metadata"): SVGMetadataElement | null;
+    querySelector(selectors: "meter"): HTMLMeterElement | null;
+    querySelector(selectors: "nav"): HTMLElement | null;
+    querySelector(selectors: "nextid"): HTMLUnknownElement | null;
+    querySelector(selectors: "nobr"): HTMLElement | null;
+    querySelector(selectors: "noframes"): HTMLElement | null;
+    querySelector(selectors: "noscript"): HTMLElement | null;
+    querySelector(selectors: "object"): HTMLObjectElement | null;
+    querySelector(selectors: "ol"): HTMLOListElement | null;
+    querySelector(selectors: "optgroup"): HTMLOptGroupElement | null;
+    querySelector(selectors: "option"): HTMLOptionElement | null;
+    querySelector(selectors: "p"): HTMLParagraphElement | null;
+    querySelector(selectors: "param"): HTMLParamElement | null;
+    querySelector(selectors: "path"): SVGPathElement | null;
+    querySelector(selectors: "pattern"): SVGPatternElement | null;
+    querySelector(selectors: "picture"): HTMLPictureElement | null;
+    querySelector(selectors: "plaintext"): HTMLElement | null;
+    querySelector(selectors: "polygon"): SVGPolygonElement | null;
+    querySelector(selectors: "polyline"): SVGPolylineElement | null;
+    querySelector(selectors: "pre"): HTMLPreElement | null;
+    querySelector(selectors: "progress"): HTMLProgressElement | null;
+    querySelector(selectors: "q"): HTMLQuoteElement | null;
+    querySelector(selectors: "radialgradient"): SVGRadialGradientElement | null;
+    querySelector(selectors: "rect"): SVGRectElement | null;
+    querySelector(selectors: "rt"): HTMLElement | null;
+    querySelector(selectors: "ruby"): HTMLElement | null;
+    querySelector(selectors: "s"): HTMLElement | null;
+    querySelector(selectors: "samp"): HTMLElement | null;
+    querySelector(selectors: "script"): HTMLScriptElement | null;
+    querySelector(selectors: "section"): HTMLElement | null;
+    querySelector(selectors: "select"): HTMLSelectElement | null;
+    querySelector(selectors: "small"): HTMLElement | null;
+    querySelector(selectors: "source"): HTMLSourceElement | null;
+    querySelector(selectors: "span"): HTMLSpanElement | null;
+    querySelector(selectors: "stop"): SVGStopElement | null;
+    querySelector(selectors: "strike"): HTMLElement | null;
+    querySelector(selectors: "strong"): HTMLElement | null;
+    querySelector(selectors: "style"): HTMLStyleElement | null;
+    querySelector(selectors: "sub"): HTMLElement | null;
+    querySelector(selectors: "sup"): HTMLElement | null;
+    querySelector(selectors: "svg"): SVGSVGElement | null;
+    querySelector(selectors: "switch"): SVGSwitchElement | null;
+    querySelector(selectors: "symbol"): SVGSymbolElement | null;
+    querySelector(selectors: "table"): HTMLTableElement | null;
+    querySelector(selectors: "tbody"): HTMLTableSectionElement | null;
+    querySelector(selectors: "td"): HTMLTableDataCellElement | null;
+    querySelector(selectors: "template"): HTMLTemplateElement | null;
+    querySelector(selectors: "text"): SVGTextElement | null;
+    querySelector(selectors: "textpath"): SVGTextPathElement | null;
+    querySelector(selectors: "textarea"): HTMLTextAreaElement | null;
+    querySelector(selectors: "tfoot"): HTMLTableSectionElement | null;
+    querySelector(selectors: "th"): HTMLTableHeaderCellElement | null;
+    querySelector(selectors: "thead"): HTMLTableSectionElement | null;
+    querySelector(selectors: "title"): HTMLTitleElement | null;
+    querySelector(selectors: "tr"): HTMLTableRowElement | null;
+    querySelector(selectors: "track"): HTMLTrackElement | null;
+    querySelector(selectors: "tspan"): SVGTSpanElement | null;
+    querySelector(selectors: "tt"): HTMLElement | null;
+    querySelector(selectors: "u"): HTMLElement | null;
+    querySelector(selectors: "ul"): HTMLUListElement | null;
+    querySelector(selectors: "use"): SVGUseElement | null;
+    querySelector(selectors: "var"): HTMLElement | null;
+    querySelector(selectors: "video"): HTMLVideoElement | null;
+    querySelector(selectors: "view"): SVGViewElement | null;
+    querySelector(selectors: "wbr"): HTMLElement | null;
+    querySelector(selectors: "x-ms-webview"): MSHTMLWebViewElement | null;
+    querySelector(selectors: "xmp"): HTMLPreElement | null;
+    querySelector(selectors: string): Element | null;
     querySelectorAll(selectors: "a"): NodeListOf<HTMLAnchorElement>;
     querySelectorAll(selectors: "abbr"): NodeListOf<HTMLElement>;
     querySelectorAll(selectors: "acronym"): NodeListOf<HTMLElement>;
@@ -14029,6 +14043,20 @@ interface ProgressEventInit extends EventInit {
     total?: number;
 }
 
+interface ScrollOptions {
+    behavior?: ScrollBehavior;
+}
+
+interface ScrollToOptions extends ScrollOptions {
+    left?: number;
+    top?: number;
+}
+
+interface ScrollIntoViewOptions extends ScrollOptions {
+    block?: ScrollLogicalPosition;
+    inline?: ScrollLogicalPosition;
+}
+
 interface ClipboardEventInit extends EventInit {
     data?: string;
     dataType?: string;
@@ -14072,7 +14100,7 @@ interface EcdsaParams extends Algorithm {
 }
 
 interface EcKeyGenParams extends Algorithm {
-    typedCurve: string;
+    namedCurve: string;
 }
 
 interface EcKeyAlgorithm extends KeyAlgorithm {
@@ -14208,6 +14236,13 @@ interface JsonWebKey {
     k?: string;
 }
 
+interface ParentNode {
+    readonly children: HTMLCollection;
+    readonly firstElementChild: Element;
+    readonly lastElementChild: Element;
+    readonly childElementCount: number;
+}
+
 declare type EventListenerOrEventListenerObject = EventListener | EventListenerObject;
 
 interface ErrorEventHandler {
@@ -14278,7 +14313,7 @@ declare var location: Location;
 declare var locationbar: BarProp;
 declare var menubar: BarProp;
 declare var msCredentials: MSCredentials;
-declare var name: string;
+declare const name: never;
 declare var navigator: Navigator;
 declare var offscreenBuffering: string | boolean;
 declare var onabort: (this: Window, ev: UIEvent) => any;
@@ -14372,7 +14407,7 @@ declare var ontouchstart: (ev: TouchEvent) => any;
 declare var onunload: (this: Window, ev: Event) => any;
 declare var onvolumechange: (this: Window, ev: Event) => any;
 declare var onwaiting: (this: Window, ev: Event) => any;
-declare var opener: Window;
+declare var opener: any;
 declare var orientation: string | number;
 declare var outerHeight: number;
 declare var outerWidth: number;
@@ -14425,6 +14460,9 @@ declare function webkitCancelAnimationFrame(handle: number): void;
 declare function webkitConvertPointFromNodeToPage(node: Node, pt: WebKitPoint): WebKitPoint;
 declare function webkitConvertPointFromPageToNode(node: Node, pt: WebKitPoint): WebKitPoint;
 declare function webkitRequestAnimationFrame(callback: FrameRequestCallback): number;
+declare function scroll(options?: ScrollToOptions): void;
+declare function scrollTo(options?: ScrollToOptions): void;
+declare function scrollBy(options?: ScrollToOptions): void;
 declare function toString(): string;
 declare function addEventListener(type: string, listener?: EventListenerOrEventListenerObject, useCapture?: boolean): void;
 declare function dispatchEvent(evt: Event): boolean;
@@ -14580,6 +14618,9 @@ type MSOutboundPayload = MSVideoSendPayload | MSAudioSendPayload;
 type RTCIceGatherCandidate = RTCIceCandidate | RTCIceCandidateComplete;
 type RTCTransport = RTCDtlsTransport | RTCSrtpSdesTransport;
 type payloadtype = number;
+type ScrollBehavior = "auto" | "instant" | "smooth";
+type ScrollLogicalPosition = "start" | "center" | "end" | "nearest";
 type IDBValidKey = number | string | Date | IDBArrayKey;
 type BufferSource = ArrayBuffer | ArrayBufferView;
-type MouseWheelEvent = WheelEvent;
+type MouseWheelEvent = WheelEvent;
+type ScrollRestoration = "auto" | "manual";

src/lib/dom.iterable.d.ts

@@ -1,4 +1,4 @@
-/// <reference path="lib.dom.generated.d.ts" />
+/// <reference path="lib.dom.d.ts" />
 
 interface DOMTokenList {
     [Symbol.iterator](): IterableIterator<string>;