diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index e339cd390f5..e6c3e647220 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -5678,7 +5678,7 @@ namespace ts {
                         }
                     }
                     if (target.flags & TypeFlags.Union) {
-                        if (result = typeRelatedToSomeType(source, <UnionType>target, reportErrors)) {
+                        if (result = typeRelatedToSomeType(source, <UnionType>target, reportErrors && !(source.flags & TypeFlags.Primitive))) {
                             return result;
                         }
                     }
diff --git a/src/compiler/comments.ts b/src/compiler/comments.ts
index 1baf1847f04..3e02558117b 100644
--- a/src/compiler/comments.ts
+++ b/src/compiler/comments.ts
@@ -13,7 +13,10 @@ namespace ts {
         getTrailingCommentsOfPosition(pos: number): CommentRange[];
         emitLeadingComments(range: TextRange, comments: CommentRange[]): void;
         emitTrailingComments(range: TextRange, comments: CommentRange[]): void;
-        emitDetachedComments(range: TextRange): void;
+        emitLeadingDetachedComments(range: TextRange): void;
+        emitLeadingDetachedComments(range: TextRange, contextNode: Node, shouldSkipCommentsForNodeCallback: (node: Node) => boolean): void;
+        emitTrailingDetachedComments(range: TextRange): void;
+        emitTrailingDetachedComments(range: TextRange, contextNode: Node, shouldSkipCommentsForNodeCallback: (node: Node) => boolean): void;
     }
 
     export function createCommentWriter(host: EmitHost, writer: EmitTextWriter, sourceMap: SourceMapWriter): CommentWriter {
@@ -46,10 +49,15 @@ namespace ts {
                 getTrailingCommentsOfPosition(pos: number): CommentRange[] { return undefined; },
                 emitLeadingComments(range: TextRange, comments: CommentRange[]): void { },
                 emitTrailingComments(range: TextRange, comments: CommentRange[]): void { },
-                emitDetachedComments,
+                emitLeadingDetachedComments,
+                emitTrailingDetachedComments(node: TextRange, contextNode?: Node, shouldSkipCommentsForNodeCallback?: (node: Node) => boolean): void {}
             };
 
-            function emitDetachedComments(node: TextRange): void {
+            function emitLeadingDetachedComments(node: TextRange, contextNode?: Node, shouldSkipCommentsForNodeCallback?: (node: Node) => boolean): void {
+                if (shouldSkipCommentsForNodeCallback && shouldSkipCommentsForNodeCallback(contextNode)) {
+                    return;
+                }
+
                 emitDetachedCommentsAndUpdateCommentsInfo(node, /*removeComments*/ true);
             }
         }
@@ -65,7 +73,8 @@ namespace ts {
                 getTrailingCommentsOfPosition,
                 emitLeadingComments,
                 emitTrailingComments,
-                emitDetachedComments,
+                emitLeadingDetachedComments,
+                emitTrailingDetachedComments
             };
 
             function getLeadingComments(range: Node, shouldSkipCommentsForNodeCallback?: (node: Node) => boolean): CommentRange[];
@@ -154,10 +163,23 @@ namespace ts {
                 emitComments(currentText, currentLineMap, writer, comments, /*leadingSeparator*/ true, /*trailingSeparator*/ false, newLine, writeComment);
             }
 
-            function emitDetachedComments(range: TextRange) {
+            function emitLeadingDetachedComments(range: TextRange, contextNode?: Node, shouldSkipCommentsForNodeCallback?: (node: Node) => boolean): void {
+                if (shouldSkipCommentsForNodeCallback && shouldSkipCommentsForNodeCallback(contextNode)) {
+                    return;
+                }
+
                 emitDetachedCommentsAndUpdateCommentsInfo(range, /*removeComments*/ false);
             }
 
+            function emitTrailingDetachedComments(range: TextRange, contextNode?: Node, shouldSkipCommentsForNodeCallback?: (node: Node) => boolean): void {
+                if (shouldSkipCommentsForNodeCallback && shouldSkipCommentsForNodeCallback(contextNode)) {
+                    return;
+                }
+
+                range = collapseRangeToEnd(range);
+                emitLeadingComments(range, getLeadingComments(range));
+            }
+
             function hasConsumedCommentRange(comment: CommentRange) {
                 return comment.end === consumedCommentRanges[comment.pos];
             }
diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
index 928ba76699e..8721a03ad71 100644
--- a/src/compiler/factory.ts
+++ b/src/compiler/factory.ts
@@ -651,13 +651,14 @@ namespace ts {
 
     /**
      * Creates a synthetic expression to act as a placeholder for a not-emitted expression in
-     * order to preserve comments.
+     * order to preserve comments or sourcemap positions.
      *
      * @param expression The inner expression to emit.
      * @param original The original outer expression.
+     * @param location The location for the expression. Defaults to the positions from "original" if provided.
      */
-    export function createPartiallyEmittedExpression(expression: Expression, original: Node) {
-        const node = <PartiallyEmittedExpression>createNode(SyntaxKind.PartiallyEmittedExpression, /*location*/ original);
+    export function createPartiallyEmittedExpression(expression: Expression, original?: Node, location?: TextRange) {
+        const node = <PartiallyEmittedExpression>createNode(SyntaxKind.PartiallyEmittedExpression, /*location*/ location || original);
         node.expression = expression;
         node.original = original;
         return node;
@@ -1257,7 +1258,7 @@ namespace ts {
      * The function needs to be called during each transformation step.
      * This function needs to be called whenever we transform the statement
      * list of a source file, namespace, or function-like body.
-     * 
+     *
      * @param target: result statements array
      * @param source: origin statements array
      * @param ensureUseStrict: boolean determining whether the function need to add prologue-directives
diff --git a/src/compiler/printer.ts b/src/compiler/printer.ts
index 451e002d5bf..b5cc8206688 100644
--- a/src/compiler/printer.ts
+++ b/src/compiler/printer.ts
@@ -140,7 +140,8 @@ const _super = (function (geti, seti) {
                 getTrailingCommentsOfPosition,
                 emitLeadingComments,
                 emitTrailingComments,
-                emitDetachedComments
+                emitLeadingDetachedComments,
+                emitTrailingDetachedComments
             } = comments;
 
             let context: TransformationContext;
@@ -298,24 +299,45 @@ const _super = (function (geti, seti) {
                     const leadingComments = getLeadingComments(node, shouldSkipCommentsForNode);
                     const trailingComments = getTrailingComments(node, shouldSkipCommentsForNode);
                     emitLeadingComments(node, leadingComments);
-                    emitStart(node, shouldIgnoreSourceMapForNode, shouldIgnoreSourceMapForChildren);
+                    emitStart(node, shouldSkipSourceMapForNode, shouldSkipSourceMapForChildren);
                     emitWorker(node);
-                    emitEnd(node, shouldIgnoreSourceMapForNode, shouldIgnoreSourceMapForChildren);
+                    emitEnd(node, shouldSkipSourceMapForNode, shouldSkipSourceMapForChildren);
                     emitTrailingComments(node, trailingComments);
                 }
             }
 
+            /**
+             * Determines whether to skip comment emit for a node.
+             *
+             * We do not emit comments for NotEmittedStatement nodes or any node that has
+             * NodeEmitFlags.NoComments.
+             *
+             * @param node A Node.
+             */
             function shouldSkipCommentsForNode(node: Node) {
                 return isNotEmittedStatement(node)
                     || (getNodeEmitFlags(node) & NodeEmitFlags.NoComments) !== 0;
             }
 
-            function shouldIgnoreSourceMapForNode(node: Node) {
-                return isNotEmittedOrPartiallyEmittedNode(node)
+            /**
+             * Determines whether to skip source map emit for a node.
+             *
+             * We do not emit source maps for NotEmittedStatement nodes or any node that
+             * has NodeEmitFlags.NoSourceMap.
+             *
+             * @param node A Node.
+             */
+            function shouldSkipSourceMapForNode(node: Node) {
+                return isNotEmittedStatement(node)
                     || (getNodeEmitFlags(node) & NodeEmitFlags.NoSourceMap) !== 0;
             }
 
-            function shouldIgnoreSourceMapForChildren(node: Node) {
+            /**
+             * Determines whether to skip source map emit for a node and its children.
+             *
+             * We do not emit source maps for a node that has NodeEmitFlags.NoNestedSourceMaps.
+             */
+            function shouldSkipSourceMapForChildren(node: Node) {
                 return (getNodeEmitFlags(node) & NodeEmitFlags.NoNestedSourceMaps) !== 0;
             }
 
@@ -1064,7 +1086,6 @@ const _super = (function (geti, seti) {
                 emitDecorators(node, node.decorators);
                 emitModifiers(node, node.modifiers);
                 emitSignatureAndBody(node, emitArrowFunctionHead);
-
             }
 
             function emitArrowFunctionHead(node: ArrowFunction) {
@@ -1095,7 +1116,7 @@ const _super = (function (geti, seti) {
             }
 
             function emitPrefixUnaryExpression(node: PrefixUnaryExpression) {
-                writeToken(node.operator);
+                writeTokenText(node.operator);
                 if (shouldEmitWhitespaceBeforeOperand(node)) {
                     write(" ");
                 }
@@ -1123,7 +1144,7 @@ const _super = (function (geti, seti) {
 
             function emitPostfixUnaryExpression(node: PostfixUnaryExpression) {
                 emitExpression(node.operand);
-                writeToken(node.operator);
+                writeTokenText(node.operator);
             }
 
             function emitBinaryExpression(node: BinaryExpression) {
@@ -1375,7 +1396,8 @@ const _super = (function (geti, seti) {
             }
 
             function emitDebuggerStatement(node: DebuggerStatement) {
-                write("debugger;");
+                writeToken(SyntaxKind.DebuggerKeyword, node.pos);
+                write(";");
             }
 
             //
@@ -1417,10 +1439,7 @@ const _super = (function (geti, seti) {
                         tempFlags = 0;
                         startLexicalEnvironment();
                         emitSignatureHead(node);
-                        write(" {");
-                        emitBlockFunctionBody(node, body);
-                        write("}");
-
+                        emitBlockFunctionBodyAndEndLexicalEnvironment(node, body);
                         if (indentedFlag) {
                             decreaseIndent();
                         }
@@ -1484,10 +1503,12 @@ const _super = (function (geti, seti) {
                 return true;
             }
 
-            function emitBlockFunctionBody(parentNode: Node, body: Block) {
+            function emitBlockFunctionBodyAndEndLexicalEnvironment(parentNode: Node, body: Block) {
+                write(" {");
+
                 const startingLine = writer.getLine();
                 increaseIndent();
-                emitDetachedComments(body.statements);
+                emitLeadingDetachedComments(body.statements, body, shouldSkipCommentsForNode);
 
                 // Emit all the prologue directives (like "use strict").
                 const statementOffset = emitPrologueDirectives(body.statements, /*startWithNewLine*/ true);
@@ -1504,13 +1525,9 @@ const _super = (function (geti, seti) {
 
                 const endingLine = writer.getLine();
                 emitLexicalEnvironment(endLexicalEnvironment(), /*newLine*/ startingLine !== endingLine);
-
-                // Do not emit leading comments if the body belongs to arrow expression
-                if (!body.original || isBlock(body.original)) {
-                    const range = collapseRangeToEnd(body.statements);
-                    emitLeadingComments(range, getLeadingComments(range));
-                }
+                emitTrailingDetachedComments(body.statements, body, shouldSkipCommentsForNode);
                 decreaseIndent();
+                writeToken(SyntaxKind.CloseBraceToken, body.statements.end);
             }
 
             function emitClassDeclaration(node: ClassDeclaration) {
@@ -1831,7 +1848,7 @@ const _super = (function (geti, seti) {
 
             function emitHeritageClause(node: HeritageClause) {
                 write(" ");
-                writeToken(node.token);
+                writeTokenText(node.token);
                 write(" ");
                 emitList(node, node.types, ListFormat.HeritageClauseTypes);
             }
@@ -1886,7 +1903,7 @@ const _super = (function (geti, seti) {
             function emitSourceFile(node: SourceFile) {
                 writeLine();
                 emitShebang();
-                emitDetachedComments(node);
+                emitLeadingDetachedComments(node);
 
                 const statements = node.statements;
                 const statementOffset = emitPrologueDirectives(statements);
@@ -1904,7 +1921,7 @@ const _super = (function (geti, seti) {
                     tempFlags = savedTempFlags;
                 }
 
-                emitLeadingComments(node.endOfFileToken, getLeadingComments(node.endOfFileToken));
+                emitTrailingDetachedComments(node.statements);
             }
 
             // Transformation nodes
@@ -2284,10 +2301,10 @@ const _super = (function (geti, seti) {
                 }
             }
 
-            function writeToken(token: SyntaxKind, pos?: number) {
-                const tokenStartPos = skipTrivia(currentText, pos);
+            function writeToken(token: SyntaxKind, tokenStartPos: number) {
+                tokenStartPos = skipTrivia(currentText, tokenStartPos);
                 emitPos(tokenStartPos);
-                const tokenEndPos = writeTokenText(token, pos);
+                const tokenEndPos = writeTokenText(token, tokenStartPos);
                 emitPos(tokenEndPos);
                 return tokenEndPos;
             }
@@ -2300,9 +2317,9 @@ const _super = (function (geti, seti) {
 
             function writeTokenNode(node: Node) {
                 if (node) {
-                    emitStart(node, shouldIgnoreSourceMapForNode, shouldIgnoreSourceMapForChildren);
+                    emitStart(node, shouldSkipSourceMapForNode, shouldSkipSourceMapForChildren);
                     writeTokenText(node.kind);
-                    emitEnd(node, shouldIgnoreSourceMapForNode, shouldIgnoreSourceMapForChildren);
+                    emitEnd(node, shouldSkipSourceMapForNode, shouldSkipSourceMapForChildren);
                 }
             }
 
diff --git a/src/compiler/transformers/es6.ts b/src/compiler/transformers/es6.ts
index 0d0ab884cca..8a001450c69 100644
--- a/src/compiler/transformers/es6.ts
+++ b/src/compiler/transformers/es6.ts
@@ -156,6 +156,7 @@ namespace ts {
         context.expressionSubstitution = substituteExpression;
 
         let currentSourceFile: SourceFile;
+        let currentText: string;
         let currentParent: Node;
         let currentNode: Node;
         let enclosingBlockScopeContainer: Node;
@@ -183,6 +184,7 @@ namespace ts {
 
         function transformSourceFile(node: SourceFile) {
             currentSourceFile = node;
+            currentText = node.text;
             return visitNode(node, visitor, isSourceFile);
         }
 
@@ -609,6 +611,8 @@ namespace ts {
             if (node.name) {
                 enableSubstitutionsForBlockScopedBindings();
             }
+
+            const closingBraceLocation = { pos: node.end - 1, end: node.end };
             const baseTypeNode = getClassExtendsHeritageClauseElement(node);
             const classFunction = createFunctionExpression(
                 /*asteriskToken*/ undefined,
@@ -624,9 +628,19 @@ namespace ts {
                 setNodeEmitFlags(classFunction, NodeEmitFlags.Indented);
             }
 
+            // "inner" and "outer" below are added purely to preserve source map locations from
+            // the old emitter
+            const inner = createPartiallyEmittedExpression(classFunction);
+            inner.end = node.end;
+            setNodeEmitFlags(inner, NodeEmitFlags.NoComments);
+
+            const outer = createPartiallyEmittedExpression(inner);
+            outer.end = node.pos;
+            setNodeEmitFlags(outer, NodeEmitFlags.NoComments);
+
             return createParen(
                 createCall(
-                    classFunction,
+                    outer,
                     baseTypeNode
                         ? [visitNode(baseTypeNode.expression, visitor, isExpression)]
                         : []
@@ -646,9 +660,27 @@ namespace ts {
             addExtendsHelperIfNeeded(statements, node, hasExtendsClause);
             addConstructor(statements, node, hasExtendsClause);
             addClassMembers(statements, node);
-            statements.push(createReturn(getDeclarationName(node)));
+
+            // Create a synthetic text range for the return statement.
+            const closingBraceLocation = createTokenRange(skipTrivia(currentText, node.members.end), SyntaxKind.CloseBraceToken);
+            const name = getDeclarationName(node);
+
+            // The following partially-emitted expression exists purely to align our sourcemap
+            // emit with the original emitter.
+            const outer = createPartiallyEmittedExpression(name);
+            outer.end = closingBraceLocation.end;
+            setNodeEmitFlags(outer, NodeEmitFlags.NoComments);
+
+            const statement = createReturn(outer);
+            statement.pos = closingBraceLocation.pos;
+            statements.push(statement);
+            setNodeEmitFlags(statement, NodeEmitFlags.NoComments);
+
             addRange(statements, endLexicalEnvironment());
-            return createBlock(statements, /*location*/ undefined, /*multiLine*/ true);
+            const block = createBlock(createNodeArray(statements, /*location*/ node.members), /*location*/ undefined, /*multiLine*/ true);
+            setNodeEmitFlags(block, NodeEmitFlags.NoComments);
+
+            return block;
         }
 
         /**
@@ -684,8 +716,8 @@ namespace ts {
                     /*asteriskToken*/ undefined,
                     getDeclarationName(node),
                     transformConstructorParameters(constructor, hasSynthesizedSuper),
-                    transformConstructorBody(constructor, hasExtendsClause, hasSynthesizedSuper),
-                    /*location*/ constructor
+                    transformConstructorBody(constructor, node, hasExtendsClause, hasSynthesizedSuper),
+                    /*location*/ constructor || node
                 )
             );
         }
@@ -714,11 +746,12 @@ namespace ts {
          * Transforms the body of a constructor declaration of a class.
          *
          * @param constructor The constructor for the class.
+         * @param node The node which contains the constructor.
          * @param hasExtendsClause A value indicating whether the class has an `extends` clause.
          * @param hasSynthesizedSuper A value indicating whether the constructor starts with a
          *                            synthesized `super` call.
          */
-        function transformConstructorBody(constructor: ConstructorDeclaration, hasExtendsClause: boolean, hasSynthesizedSuper: boolean) {
+        function transformConstructorBody(constructor: ConstructorDeclaration, node: ClassDeclaration | ClassExpression, hasExtendsClause: boolean, hasSynthesizedSuper: boolean) {
             const statements: Statement[] = [];
             startLexicalEnvironment();
             if (constructor) {
@@ -735,14 +768,20 @@ namespace ts {
             }
 
             addRange(statements, endLexicalEnvironment());
-            return createBlock(
+            const block = createBlock(
                 createNodeArray(
                     statements,
-                    /*location*/ constructor ? constructor.body.statements : undefined
+                    /*location*/ constructor ? constructor.body.statements : node.members
                 ),
-                /*location*/ constructor ? constructor.body : undefined,
+                /*location*/ constructor ? constructor.body : node,
                 /*multiLine*/ true
             );
+
+            if (!constructor) {
+                setNodeEmitFlags(block, NodeEmitFlags.NoComments);
+            }
+
+            return block;
         }
 
         function transformConstructorBodyWithSynthesizedSuper(node: ConstructorDeclaration) {
@@ -1073,16 +1112,24 @@ namespace ts {
          * @param member The MethodDeclaration node.
          */
         function transformClassMethodDeclarationToStatement(receiver: LeftHandSideExpression, member: MethodDeclaration) {
-            return createStatement(
+            const statement = createStatement(
                 createAssignment(
                     createMemberAccessForPropertyName(
                         receiver,
-                        visitNode(member.name, visitor, isPropertyName)
+                        visitNode(member.name, visitor, isPropertyName),
+                        /*location*/ member.name
                     ),
-                    transformFunctionLikeToExpression(member, /*location*/ undefined, /*name*/ undefined)
+                    transformFunctionLikeToExpression(member, /*location*/ member, /*name*/ undefined),
+                    /*location*/ moveRangeEnd(member, -1)
                 ),
                 /*location*/ member
             );
+
+            // The location for the statement is used to emit comments only.
+            // No source map should be emitted for this statement to align with the
+            // old emitter.
+            setNodeEmitFlags(statement, NodeEmitFlags.NoSourceMap);
+            return statement;
         }
 
         /**
@@ -1092,9 +1139,16 @@ namespace ts {
          * @param accessors The set of related get/set accessors.
          */
         function transformAccessorsToStatement(receiver: LeftHandSideExpression, accessors: AllAccessorDeclarations): Statement {
-            return createStatement(
-                transformAccessorsToExpression(receiver, accessors)
+            const statement = createStatement(
+                transformAccessorsToExpression(receiver, accessors),
+                /*location*/ accessors.firstAccessor
             );
+
+            // The location for the statement is used to emit source maps only.
+            // No comments should be emitted for this statement to align with the
+            // old emitter.
+            setNodeEmitFlags(statement, NodeEmitFlags.NoComments);
+            return statement;
         }
 
         /**
@@ -1118,7 +1172,7 @@ namespace ts {
                         configurable: true
                     },
                     /*preferNewLine*/ true,
-                    /*location*/ firstAccessor,
+                    /*location*/ undefined,
                     /*descriptorLocations*/ {
                         get: getAccessor,
                         set: setAccessor
@@ -1220,6 +1274,7 @@ namespace ts {
                 // addPrologueDirectives will simply put already-existing directives at the beginning of the target statement-array
                 statementOffset = addPrologueDirectives(statements, body.statements, /*ensureUseStrict*/ false);
             }
+
             addCaptureThisForNodeIfNeeded(statements, node);
             addDefaultValueAssignmentsIfNeeded(statements, node);
             addRestParameterIfNeeded(statements, node, /*inConstructorWithSynthesizedSuper*/ false);
@@ -1240,7 +1295,12 @@ namespace ts {
             }
             else {
                 Debug.assert(node.kind === SyntaxKind.ArrowFunction);
-                statementsLocation = body;
+
+                // To align with the old emitter, we use a synthetic end position on the location
+                // for the statement list we synthesize when we down-level an arrow function with
+                // an expression function body. This prevents both comments and source maps from
+                // being emitted for the end position only.
+                statementsLocation = moveRangeEnd(body, -1);
 
                 const equalsGreaterThanToken = (<ArrowFunction>node).equalsGreaterThanToken;
                 if (!nodeIsSynthesized(equalsGreaterThanToken) && !nodeIsSynthesized(body)) {
@@ -1254,7 +1314,7 @@ namespace ts {
 
                 const expression = visitNode(body, visitor, isExpression);
                 if (expression) {
-                    statements.push(createReturn(expression));
+                    statements.push(createReturn(expression, /*location*/ statementsLocation));
                 }
             }
 
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index bf6881b9810..8b09e521d51 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -2943,12 +2943,63 @@ namespace ts {
         }
     }
 
-    export function collapseRangeToStart(range: TextRange) {
-        return range.pos === range.end ? range : { pos: range.pos, end: range.pos };
+    /**
+     * Creates a new TextRange from a provided range with a new end position.
+     *
+     * @param range A TextRange.
+     * @param end The new end position.
+     */
+    export function moveRangeEnd(range: TextRange, end: number): TextRange {
+        return { pos: range.pos, end };
     }
 
-    export function collapseRangeToEnd(range: TextRange) {
-        return range.pos === range.end ? range : { pos: range.end, end: range.end };
+    /**
+     * Creates a new TextRange from a provided range with a new start position.
+     *
+     * @param range A TextRange.
+     * @param pos The new Start position.
+     */
+    export function moveRangePos(range: TextRange, pos: number): TextRange {
+        return { pos, end: range.end };
+    }
+
+    /**
+     * Determines whether a TextRange has the same start and end positions.
+     *
+     * @param range A TextRange.
+     */
+    export function isCollapsedRange(range: TextRange) {
+        return range.pos === range.end;
+    }
+
+    /**
+     * Creates a new TextRange from a provided range with its end position collapsed to its
+     * start position.
+     *
+     * @param range A TextRange.
+     */
+    export function collapseRangeToStart(range: TextRange): TextRange {
+        return isCollapsedRange(range) ? range : moveRangeEnd(range, range.pos);
+    }
+
+    /**
+     * Creates a new TextRange from a provided range with its start position collapsed to its
+     * end position.
+     *
+     * @param range A TextRange.
+     */
+    export function collapseRangeToEnd(range: TextRange): TextRange {
+        return isCollapsedRange(range) ? range : moveRangePos(range, range.end);
+    }
+
+    /**
+     * Creates a new TextRange for a token at the provides start position.
+     *
+     * @param pos The start position.
+     * @param token The token.
+     */
+    export function createTokenRange(pos: number, token: SyntaxKind): TextRange {
+        return { pos, end: pos + tokenToString(token).length };
     }
 
     export function rangeIsOnSingleLine(range: TextRange, sourceFile: SourceFile) {
diff --git a/tests/baselines/reference/contextualTypeWithTuple.errors.txt b/tests/baselines/reference/contextualTypeWithTuple.errors.txt
index e447ed62b39..a2d3b224ddc 100644
--- a/tests/baselines/reference/contextualTypeWithTuple.errors.txt
+++ b/tests/baselines/reference/contextualTypeWithTuple.errors.txt
@@ -3,7 +3,6 @@ tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(3,5): error TS232
     Type '() => number | string | boolean' is not assignable to type '() => number | string'.
       Type 'number | string | boolean' is not assignable to type 'number | string'.
         Type 'boolean' is not assignable to type 'number | string'.
-          Type 'boolean' is not assignable to type 'string'.
 tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(15,1): error TS2322: Type '[number, string, boolean]' is not assignable to type '[number, string]'.
 tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(18,1): error TS2322: Type '[{}, number]' is not assignable to type '[{ a: string; }, number]'.
   Types of property '0' are incompatible.
@@ -34,7 +33,6 @@ tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts(25,1): error TS23
 !!! error TS2322:     Type '() => number | string | boolean' is not assignable to type '() => number | string'.
 !!! error TS2322:       Type 'number | string | boolean' is not assignable to type 'number | string'.
 !!! error TS2322:         Type 'boolean' is not assignable to type 'number | string'.
-!!! error TS2322:           Type 'boolean' is not assignable to type 'string'.
     var numStrBoolTuple: [number, string, boolean] = [5, "foo", true];
     var objNumTuple: [{ a: string }, number] = [{ a: "world" }, 5];
     var strTupleTuple: [string, [number, {}]] = ["bar", [5, { x: 1, y: 1 }]];
diff --git a/tests/baselines/reference/contextualTypeWithUnionTypeCallSignatures.js b/tests/baselines/reference/contextualTypeWithUnionTypeCallSignatures.js
index e29d4720cbc..bbe190f65b9 100644
--- a/tests/baselines/reference/contextualTypeWithUnionTypeCallSignatures.js
+++ b/tests/baselines/reference/contextualTypeWithUnionTypeCallSignatures.js
@@ -45,6 +45,6 @@ var x = function (a) { return a.toString(); };
 var x2 = function (a) { return a.toString(); }; // Like iWithCallSignatures
 var x2 = function (a) { return a; }; // Like iWithCallSignatures2
 // With call signatures of mismatching parameter type
-var x3 = function (a) { return a.toString(); };
+var x3 = function (a) { /*here a should be any*/ return a.toString(); };
 // With call signature count mismatch
-var x4 = function (a) { return a.toString(); };
+var x4 = function (a) { /*here a should be any*/ return a.toString(); };
diff --git a/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.errors.txt b/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.errors.txt
index 689645386c4..42d617887e0 100644
--- a/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.errors.txt
+++ b/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.errors.txt
@@ -14,7 +14,6 @@ tests/cases/conformance/types/contextualTypes/methodDeclarations/contextuallyTyp
   Types of property '0' are incompatible.
     Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/contextualTypes/methodDeclarations/contextuallyTypedBindingInitializerNegative.ts(26,14): error TS2322: Type '"baz"' is not assignable to type '"foo" | "bar"'.
-  Type '"baz"' is not assignable to type '"bar"'.
 
 
 ==== tests/cases/conformance/types/contextualTypes/methodDeclarations/contextuallyTypedBindingInitializerNegative.ts (7 errors) ====
@@ -67,5 +66,4 @@ tests/cases/conformance/types/contextualTypes/methodDeclarations/contextuallyTyp
     function h({ prop = "baz" }: StringUnion) {}
                  ~~~~
 !!! error TS2322: Type '"baz"' is not assignable to type '"foo" | "bar"'.
-!!! error TS2322:   Type '"baz"' is not assignable to type '"bar"'.
     
\ No newline at end of file
diff --git a/tests/baselines/reference/contextuallyTypedStringLiteralsInJsxAttributes01.errors.txt b/tests/baselines/reference/contextuallyTypedStringLiteralsInJsxAttributes01.errors.txt
index 32b86e455d2..48e11fb1221 100644
--- a/tests/baselines/reference/contextuallyTypedStringLiteralsInJsxAttributes01.errors.txt
+++ b/tests/baselines/reference/contextuallyTypedStringLiteralsInJsxAttributes01.errors.txt
@@ -1,7 +1,5 @@
 tests/cases/conformance/types/contextualTypes/jsxAttributes/contextuallyTypedStringLiteralsInJsxAttributes01.tsx(16,15): error TS2322: Type '"f"' is not assignable to type '"A" | "B" | "C"'.
-  Type '"f"' is not assignable to type '"C"'.
 tests/cases/conformance/types/contextualTypes/jsxAttributes/contextuallyTypedStringLiteralsInJsxAttributes01.tsx(17,15): error TS2322: Type '"f"' is not assignable to type '"A" | "B" | "C"'.
-  Type '"f"' is not assignable to type '"C"'.
 
 
 ==== tests/cases/conformance/types/contextualTypes/jsxAttributes/contextuallyTypedStringLiteralsInJsxAttributes01.tsx (2 errors) ====
@@ -23,8 +21,6 @@ tests/cases/conformance/types/contextualTypes/jsxAttributes/contextuallyTypedStr
     <FooComponent foo={"f"} />;
                   ~~~~~~~~~
 !!! error TS2322: Type '"f"' is not assignable to type '"A" | "B" | "C"'.
-!!! error TS2322:   Type '"f"' is not assignable to type '"C"'.
     <FooComponent foo="f"   />;
                   ~~~~~~~
-!!! error TS2322: Type '"f"' is not assignable to type '"A" | "B" | "C"'.
-!!! error TS2322:   Type '"f"' is not assignable to type '"C"'.
\ No newline at end of file
+!!! error TS2322: Type '"f"' is not assignable to type '"A" | "B" | "C"'.
\ No newline at end of file
diff --git a/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt b/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt
index 114efc14d9c..d68220c8308 100644
--- a/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt
+++ b/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt
@@ -7,7 +7,6 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
     Type '() => number | string[][] | string' is not assignable to type '() => number | string[][]'.
       Type 'number | string[][] | string' is not assignable to type 'number | string[][]'.
         Type 'string' is not assignable to type 'number | string[][]'.
-          Type 'string' is not assignable to type 'string[][]'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(16,8): error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(16,16): error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(23,14): error TS2345: Argument of type '{ x: string; y: boolean; }' is not assignable to parameter of type '{ x: number; y: any; }'.
@@ -29,7 +28,6 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(38,4): error TS2345: Argument of type '{ b: boolean; }' is not assignable to parameter of type '{ b: number | string; }'.
   Types of property 'b' are incompatible.
     Type 'boolean' is not assignable to type 'number | string'.
-      Type 'boolean' is not assignable to type 'string'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(39,4): error TS2345: Argument of type '[number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
   Types of property '2' are incompatible.
     Type 'boolean' is not assignable to type '[[any]]'.
@@ -75,7 +73,6 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
 !!! error TS2345:     Type '() => number | string[][] | string' is not assignable to type '() => number | string[][]'.
 !!! error TS2345:       Type 'number | string[][] | string' is not assignable to type 'number | string[][]'.
 !!! error TS2345:         Type 'string' is not assignable to type 'number | string[][]'.
-!!! error TS2345:           Type 'string' is not assignable to type 'string[][]'.
     
     
     // If the declaration includes an initializer expression (which is permitted only
@@ -137,7 +134,6 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
 !!! error TS2345: Argument of type '{ b: boolean; }' is not assignable to parameter of type '{ b: number | string; }'.
 !!! error TS2345:   Types of property 'b' are incompatible.
 !!! error TS2345:     Type 'boolean' is not assignable to type 'number | string'.
-!!! error TS2345:       Type 'boolean' is not assignable to type 'string'.
     c5([1, 2, false, true]);   // Error, implied type is [any, any, [[any]]]
        ~~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type '[number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
diff --git a/tests/baselines/reference/destructuringParameterDeclaration4.errors.txt b/tests/baselines/reference/destructuringParameterDeclaration4.errors.txt
index b08c5b942d8..aa5a8e8daea 100644
--- a/tests/baselines/reference/destructuringParameterDeclaration4.errors.txt
+++ b/tests/baselines/reference/destructuringParameterDeclaration4.errors.txt
@@ -1,7 +1,6 @@
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(11,13): error TS2370: A rest parameter must be of an array type.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(13,13): error TS2370: A rest parameter must be of an array type.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(20,19): error TS2345: Argument of type 'boolean' is not assignable to parameter of type 'number | string'.
-  Type 'boolean' is not assignable to type 'string'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(21,7): error TS2304: Cannot find name 'array2'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(22,4): error TS2345: Argument of type '[number, number, string, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
   Types of property '2' are incompatible.
@@ -43,7 +42,6 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(
     a1(1, 2, "hello", true);  // Error, parameter type is (number|string)[]
                       ~~~~
 !!! error TS2345: Argument of type 'boolean' is not assignable to parameter of type 'number | string'.
-!!! error TS2345:   Type 'boolean' is not assignable to type 'string'.
     a1(...array2);            // Error parameter type is (number|string)[]
           ~~~~~~
 !!! error TS2304: Cannot find name 'array2'.
diff --git a/tests/baselines/reference/errorMessagesIntersectionTypes02.errors.txt b/tests/baselines/reference/errorMessagesIntersectionTypes02.errors.txt
index 06e06c87015..6a9dd26706c 100644
--- a/tests/baselines/reference/errorMessagesIntersectionTypes02.errors.txt
+++ b/tests/baselines/reference/errorMessagesIntersectionTypes02.errors.txt
@@ -1,7 +1,6 @@
 tests/cases/compiler/errorMessagesIntersectionTypes02.ts(14,5): error TS2322: Type '{ fooProp: string; } & Bar' is not assignable to type 'FooBar'.
   Types of property 'fooProp' are incompatible.
     Type 'string' is not assignable to type '"hello" | "world"'.
-      Type 'string' is not assignable to type '"world"'.
 
 
 ==== tests/cases/compiler/errorMessagesIntersectionTypes02.ts (1 errors) ====
@@ -23,6 +22,5 @@ tests/cases/compiler/errorMessagesIntersectionTypes02.ts(14,5): error TS2322: Ty
 !!! error TS2322: Type '{ fooProp: string; } & Bar' is not assignable to type 'FooBar'.
 !!! error TS2322:   Types of property 'fooProp' are incompatible.
 !!! error TS2322:     Type 'string' is not assignable to type '"hello" | "world"'.
-!!! error TS2322:       Type 'string' is not assignable to type '"world"'.
         fooProp: "frizzlebizzle"
     });
\ No newline at end of file
diff --git a/tests/baselines/reference/genericCallWithTupleType.errors.txt b/tests/baselines/reference/genericCallWithTupleType.errors.txt
index bcf580320e5..24e0505d009 100644
--- a/tests/baselines/reference/genericCallWithTupleType.errors.txt
+++ b/tests/baselines/reference/genericCallWithTupleType.errors.txt
@@ -3,7 +3,6 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTup
     Type '() => string | number | boolean' is not assignable to type '() => string | number'.
       Type 'string | number | boolean' is not assignable to type 'string | number'.
         Type 'boolean' is not assignable to type 'string | number'.
-          Type 'boolean' is not assignable to type 'number'.
 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTupleType.ts(14,1): error TS2322: Type '{ a: string; }' is not assignable to type 'string | number'.
   Type '{ a: string; }' is not assignable to type 'number'.
 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTupleType.ts(22,1): error TS2322: Type '[number, string]' is not assignable to type '[string, number]'.
@@ -35,7 +34,6 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTup
 !!! error TS2322:     Type '() => string | number | boolean' is not assignable to type '() => string | number'.
 !!! error TS2322:       Type 'string | number | boolean' is not assignable to type 'string | number'.
 !!! error TS2322:         Type 'boolean' is not assignable to type 'string | number'.
-!!! error TS2322:           Type 'boolean' is not assignable to type 'number'.
     var e3 = i1.tuple1[2];  // {}
     i1.tuple1[3] = { a: "string" };
     ~~~~~~~~~~~~
diff --git a/tests/baselines/reference/iteratorSpreadInCall6.errors.txt b/tests/baselines/reference/iteratorSpreadInCall6.errors.txt
index 0a0da985ace..ee9945f7af6 100644
--- a/tests/baselines/reference/iteratorSpreadInCall6.errors.txt
+++ b/tests/baselines/reference/iteratorSpreadInCall6.errors.txt
@@ -1,12 +1,10 @@
 tests/cases/conformance/es6/spread/iteratorSpreadInCall6.ts(1,28): error TS2345: Argument of type 'string' is not assignable to parameter of type 'symbol | number'.
-  Type 'string' is not assignable to type 'number'.
 
 
 ==== tests/cases/conformance/es6/spread/iteratorSpreadInCall6.ts (1 errors) ====
     foo(...new SymbolIterator, ...new StringIterator);
                                ~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type 'string' is not assignable to parameter of type 'symbol | number'.
-!!! error TS2345:   Type 'string' is not assignable to type 'number'.
     
     function foo(...s: (symbol | number)[]) { }
     class SymbolIterator {
diff --git a/tests/baselines/reference/typeArgumentsWithStringLiteralTypes01.errors.txt b/tests/baselines/reference/typeArgumentsWithStringLiteralTypes01.errors.txt
index ef582ab9b26..48c7efb37e8 100644
--- a/tests/baselines/reference/typeArgumentsWithStringLiteralTypes01.errors.txt
+++ b/tests/baselines/reference/typeArgumentsWithStringLiteralTypes01.errors.txt
@@ -4,15 +4,10 @@ tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes0
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(40,25): error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(41,25): error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(44,30): error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-  Type 'string' is not assignable to type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(45,30): error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-  Type 'string' is not assignable to type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(46,30): error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-  Type 'string' is not assignable to type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(47,30): error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-  Type 'string' is not assignable to type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(48,30): error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-  Type 'string' is not assignable to type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(55,43): error TS2345: Argument of type '"World"' is not assignable to parameter of type '"Hello"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(57,52): error TS2345: Argument of type '"World"' is not assignable to parameter of type '"Hello"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(58,43): error TS2345: Argument of type '"World"' is not assignable to parameter of type '"Hello"'.
@@ -26,9 +21,7 @@ tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes0
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(88,43): error TS2345: Argument of type '"Hello"' is not assignable to parameter of type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(89,52): error TS2345: Argument of type '"World"' is not assignable to parameter of type '"Hello"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(93,5): error TS2322: Type 'string' is not assignable to type '"Hello" | "World"'.
-  Type 'string' is not assignable to type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(97,5): error TS2322: Type 'string' is not assignable to type '"Hello" | "World"'.
-  Type 'string' is not assignable to type '"World"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(100,25): error TS2345: Argument of type '"Hello" | "World"' is not assignable to parameter of type '"Hello"'.
   Type '"World"' is not assignable to type '"Hello"'.
 tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes01.ts(104,25): error TS2345: Argument of type '"Hello" | "World"' is not assignable to parameter of type '"Hello"'.
@@ -92,23 +85,18 @@ tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes0
         a = takeReturnHelloWorld(a);
                                  ~
 !!! error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-!!! error TS2345:   Type 'string' is not assignable to type '"World"'.
         b = takeReturnHelloWorld(b);
                                  ~
 !!! error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-!!! error TS2345:   Type 'string' is not assignable to type '"World"'.
         c = takeReturnHelloWorld(c);
                                  ~
 !!! error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-!!! error TS2345:   Type 'string' is not assignable to type '"World"'.
         d = takeReturnHelloWorld(d);
                                  ~
 !!! error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-!!! error TS2345:   Type 'string' is not assignable to type '"World"'.
         e = takeReturnHelloWorld(e);
                                  ~
 !!! error TS2345: Argument of type 'string' is not assignable to parameter of type '"Hello" | "World"'.
-!!! error TS2345:   Type 'string' is not assignable to type '"World"'.
     }
     
     namespace n2 {
@@ -178,14 +166,12 @@ tests/cases/conformance/types/stringLiteral/typeArgumentsWithStringLiteralTypes0
         a = takeReturnString(a);
         ~
 !!! error TS2322: Type 'string' is not assignable to type '"Hello" | "World"'.
-!!! error TS2322:   Type 'string' is not assignable to type '"World"'.
         b = takeReturnString(b);
         c = takeReturnString(c);
         d = takeReturnString(d);
         e = takeReturnString(e);
         ~
 !!! error TS2322: Type 'string' is not assignable to type '"Hello" | "World"'.
-!!! error TS2322:   Type 'string' is not assignable to type '"World"'.
     
         // Passing these as arguments should cause an error.
         a = takeReturnHello(a);