Merge branch 'master' into mergeMaster7-12

src/compiler/binder.ts

@@ -225,11 +225,11 @@ namespace ts {
             node.symbol = symbol;
             symbol.declarations = append(symbol.declarations, node);
 
-            if (symbolFlags & SymbolFlags.HasExports && !symbol.exports) {
+            if (symbolFlags & (SymbolFlags.Class | SymbolFlags.Enum | SymbolFlags.Module | SymbolFlags.Variable) && !symbol.exports) {
                 symbol.exports = createSymbolTable();
             }
 
-            if (symbolFlags & SymbolFlags.HasMembers && !symbol.members) {
+            if (symbolFlags & (SymbolFlags.Class | SymbolFlags.Interface | SymbolFlags.TypeLiteral | SymbolFlags.ObjectLiteral) && !symbol.members) {
                 symbol.members = createSymbolTable();
             }
 

src/compiler/checker.ts

@@ -2417,12 +2417,12 @@ namespace ts {
             // The ES6 spec permits export * declarations in a module to circularly reference the module itself. For example,
             // module 'a' can 'export * from "b"' and 'b' can 'export * from "a"' without error.
             function visit(symbol: Symbol | undefined): SymbolTable | undefined {
-                if (!(symbol && symbol.flags & SymbolFlags.HasExports && pushIfUnique(visitedSymbols, symbol))) {
+                if (!(symbol && symbol.exports && pushIfUnique(visitedSymbols, symbol))) {
                     return;
                 }
-                const symbols = cloneMap(symbol.exports!);
+                const symbols = cloneMap(symbol.exports);
                 // All export * declarations are collected in an __export symbol by the binder
-                const exportStars = symbol.exports!.get(InternalSymbolName.ExportStar);
+                const exportStars = symbol.exports.get(InternalSymbolName.ExportStar);
                 if (exportStars) {
                     const nestedSymbols = createSymbolTable();
                     const lookupTable = createMap<ExportCollisionTracker>() as ExportCollisionTrackerTable;
@@ -7566,12 +7566,21 @@ namespace ts {
                 const setter = getDeclarationOfKind<AccessorDeclaration>(getSymbolOfNode(declaration), SyntaxKind.SetAccessor);
                 return getAnnotatedAccessorType(setter);
             }
-
+            const typeFromTag = getReturnTypeOfTypeTag(declaration);
+            if (typeFromTag) {
+                return typeFromTag;
+            }
             if (nodeIsMissing((<FunctionLikeDeclaration>declaration).body)) {
                 return anyType;
             }
         }
 
+        function getReturnTypeOfTypeTag(node: SignatureDeclaration | JSDocSignature) {
+            const typeTag = isInJavaScriptFile(node) ? getJSDocTypeTag(node) : undefined;
+            const signatures = typeTag && typeTag.typeExpression && getSignaturesOfType(getTypeFromTypeNode(typeTag.typeExpression), SignatureKind.Call);
+            return signatures && signatures.length === 1 ? getReturnTypeOfSignature(signatures[0]) : undefined;
+        }
+
         function containsArgumentsReference(declaration: SignatureDeclaration): boolean {
             const links = getNodeLinks(declaration);
             if (links.containsArgumentsReference === undefined) {
@@ -7702,9 +7711,13 @@ namespace ts {
             return !signature.resolvedReturnType && findResolutionCycleStartIndex(signature, TypeSystemPropertyName.ResolvedReturnType) >= 0;
         }
 
-        function getRestTypeOfSignature(signature: Signature) {
+        function getRestTypeOfSignature(signature: Signature): Type {
+            return tryGetRestTypeOfSignature(signature) || anyType;
+        }
+
+        function tryGetRestTypeOfSignature(signature: Signature): Type | undefined {
             const type = getTypeOfRestParameter(signature);
-            return type && getIndexTypeOfType(type, IndexKind.Number) || anyType;
+            return type && getIndexTypeOfType(type, IndexKind.Number);
         }
 
         function getSignatureInstantiation(signature: Signature, typeArguments: Type[] | undefined, isJavascript: boolean): Signature {
@@ -9377,11 +9390,9 @@ namespace ts {
                     links.resolvedSymbol = unknownSymbol;
                     return links.resolvedType = errorType;
                 }
-                const argumentType = getTypeFromTypeNode(node.argument);
                 const targetMeaning = node.isTypeOf ? SymbolFlags.Value : SymbolFlags.Type;
                 // TODO: Future work: support unions/generics/whatever via a deferred import-type
-                const moduleName = (argumentType as StringLiteralType).value;
-                const innerModuleSymbol = resolveExternalModule(node, moduleName, Diagnostics.Cannot_find_module_0, node, /*isForAugmentation*/ false);
+                const innerModuleSymbol = resolveExternalModuleName(node, node.argument.literal);
                 if (!innerModuleSymbol) {
                     links.resolvedSymbol = unknownSymbol;
                     return links.resolvedType = errorType;
@@ -9413,7 +9424,7 @@ namespace ts {
                             ? Diagnostics.Module_0_does_not_refer_to_a_value_but_is_used_as_a_value_here
                             : Diagnostics.Module_0_does_not_refer_to_a_type_but_is_used_as_a_type_here_Did_you_mean_typeof_import_0;
 
-                        error(node, errorMessage, moduleName);
+                        error(node, errorMessage, node.argument.literal.text);
 
                         links.resolvedSymbol = unknownSymbol;
                         links.resolvedType = errorType;
@@ -17404,7 +17415,7 @@ namespace ts {
          */
         function isKnownProperty(targetType: Type, name: __String, isComparingJsxAttributes: boolean): boolean {
             if (targetType.flags & TypeFlags.Object) {
-                const resolved = resolveStructuredTypeMembers(<ObjectType>targetType);
+                const resolved = resolveStructuredTypeMembers(targetType as ObjectType);
                 if (resolved.stringIndexInfo ||
                     resolved.numberIndexInfo && isNumericLiteralName(name) ||
                     getPropertyOfObjectType(targetType, name) ||
@@ -17414,12 +17425,16 @@ namespace ts {
                 }
             }
             else if (targetType.flags & TypeFlags.UnionOrIntersection) {
-                for (const t of (<UnionOrIntersectionType>targetType).types) {
+                for (const t of (targetType as UnionOrIntersectionType).types) {
                     if (isKnownProperty(t, name, isComparingJsxAttributes)) {
                         return true;
                     }
                 }
             }
+            else if (targetType.flags & TypeFlags.Conditional) {
+                return isKnownProperty((targetType as ConditionalType).root.trueType, name, isComparingJsxAttributes) ||
+                    isKnownProperty((targetType as ConditionalType).root.falseType, name, isComparingJsxAttributes);
+            }
             return false;
         }
 
@@ -18828,7 +18843,7 @@ namespace ts {
                 node.kind === SyntaxKind.SetAccessor) {
                 // The `descriptor` for a method decorator will be a `TypedPropertyDescriptor<T>`
                 // for the type of the member.
-                const propertyType = getTypeOfNode(node)!; // TODO: GH#18217
+                const propertyType = getTypeOfNode(node);
                 return createTypedPropertyDescriptorType(propertyType);
             }
 
@@ -19046,61 +19061,46 @@ namespace ts {
             else if (args) {
                 let min = Number.POSITIVE_INFINITY;
                 let max = Number.NEGATIVE_INFINITY;
+                let belowArgCount = Number.NEGATIVE_INFINITY;
+                let aboveArgCount = Number.POSITIVE_INFINITY;
+
+                let argCount = args.length;
                 for (const sig of signatures) {
-                    min = Math.min(min, getMinArgumentCount(sig));
-                    max = Math.max(max, getParameterCount(sig));
+                    const minCount = getMinArgumentCount(sig);
+                    const maxCount = getParameterCount(sig);
+                    if (minCount < argCount && minCount > belowArgCount) belowArgCount = minCount;
+                    if (argCount < maxCount && maxCount < aboveArgCount) aboveArgCount = maxCount;
+                    min = Math.min(min, minCount);
+                    max = Math.max(max, maxCount);
                 }
+
                 const hasRestParameter = some(signatures, hasEffectiveRestParameter);
-                const hasSpreadArgument = getSpreadArgumentIndex(args) > -1;
-                const paramCount = hasRestParameter ? min :
+                const paramRange = hasRestParameter ? min :
                     min < max ? min + "-" + max :
                     min;
-                let argCount = args.length;
+                const hasSpreadArgument = getSpreadArgumentIndex(args) > -1;
                 if (argCount <= max && hasSpreadArgument) {
                     argCount--;
                 }
-                const error = hasRestParameter && hasSpreadArgument ? Diagnostics.Expected_at_least_0_arguments_but_got_1_or_more :
-                    hasRestParameter ? Diagnostics.Expected_at_least_0_arguments_but_got_1 :
-                    hasSpreadArgument ? Diagnostics.Expected_0_arguments_but_got_1_or_more :
-                    Diagnostics.Expected_0_arguments_but_got_1;
-                diagnostics.add(createDiagnosticForNode(node, error, paramCount, argCount));
+
+                if (hasRestParameter || hasSpreadArgument) {
+                    const error = hasRestParameter && hasSpreadArgument ? Diagnostics.Expected_at_least_0_arguments_but_got_1_or_more :
+                        hasRestParameter ? Diagnostics.Expected_at_least_0_arguments_but_got_1 :
+                        Diagnostics.Expected_0_arguments_but_got_1_or_more;
+                    diagnostics.add(createDiagnosticForNode(node, error, paramRange, argCount));
+                }
+                else if (min < argCount && argCount < max) {
+                    diagnostics.add(createDiagnosticForNode(node, Diagnostics.No_overload_expects_0_arguments_but_overloads_do_exist_that_expect_either_1_or_2_arguments, argCount, belowArgCount, aboveArgCount));
+                }
+                else {
+                    diagnostics.add(createDiagnosticForNode(node, Diagnostics.Expected_0_arguments_but_got_1, paramRange, argCount));
+                }
             }
             else if (fallbackError) {
                 diagnostics.add(createDiagnosticForNode(node, fallbackError));
             }
 
-            // No signature was applicable. We have already reported the errors for the invalid signature.
-            // If this is a type resolution session, e.g. Language Service, try to get better information than anySignature.
-            // Pick the longest signature. This way we can get a contextual type for cases like:
-            //     declare function f(a: { xa: number; xb: number; }, b: number);
-            //     f({ |
-            // Also, use explicitly-supplied type arguments if they are provided, so we can get a contextual signature in cases like:
-            //     declare function f<T>(k: keyof T);
-            //     f<Foo>("
-            if (!produceDiagnostics) {
-                Debug.assert(candidates.length > 0); // Else would have exited above.
-                const bestIndex = getLongestCandidateIndex(candidates, apparentArgumentCount === undefined ? args!.length : apparentArgumentCount);
-                const candidate = candidates[bestIndex];
-
-                const { typeParameters } = candidate;
-                if (typeParameters && callLikeExpressionMayHaveTypeArguments(node) && node.typeArguments) {
-                    const typeArguments = node.typeArguments.map(getTypeOfNode) as Type[]; // TODO: GH#18217
-                    while (typeArguments.length > typeParameters.length) {
-                        typeArguments.pop();
-                    }
-                    while (typeArguments.length < typeParameters.length) {
-                        typeArguments.push(getDefaultTypeArgumentType(isInJavaScriptFile(node)));
-                    }
-
-                    const instantiated = createSignatureInstantiation(candidate, typeArguments);
-                    candidates[bestIndex] = instantiated;
-                    return instantiated;
-                }
-
-                return candidate;
-            }
-
-            return resolveErrorCall(node);
+            return produceDiagnostics || !args ? resolveErrorCall(node) : getCandidateForOverloadFailure(node, candidates, args, !!candidatesOutArray);
 
             function chooseOverload(candidates: Signature[], relation: Map<RelationComparisonResult>, signatureHelpTrailingComma = false) {
                 candidateForArgumentError = undefined;
@@ -19171,6 +19171,97 @@ namespace ts {
             }
         }
 
+        // No signature was applicable. We have already reported the errors for the invalid signature.
+        // If this is a type resolution session, e.g. Language Service, try to get better information than anySignature.
+        function getCandidateForOverloadFailure(
+            node: CallLikeExpression,
+            candidates: Signature[],
+            args: ReadonlyArray<Expression>,
+            hasCandidatesOutArray: boolean,
+        ): Signature {
+            Debug.assert(candidates.length > 0); // Else should not have called this.
+            // Normally we will combine overloads. Skip this if they have type parameters since that's hard to combine.
+            // Don't do this if there is a `candidatesOutArray`,
+            // because then we want the chosen best candidate to be one of the overloads, not a combination.
+            return hasCandidatesOutArray || candidates.length === 1 || candidates.some(c => !!c.typeParameters)
+                ? pickLongestCandidateSignature(node, candidates, args)
+                : createUnionOfSignaturesForOverloadFailure(candidates);
+        }
+
+        function createUnionOfSignaturesForOverloadFailure(candidates: ReadonlyArray<Signature>): Signature {
+            const thisParameters = mapDefined(candidates, c => c.thisParameter);
+            let thisParameter: Symbol | undefined;
+            if (thisParameters.length) {
+                thisParameter = createCombinedSymbolFromTypes(thisParameters, thisParameters.map(getTypeOfParameter));
+            }
+            const { min: minArgumentCount, max: maxNonRestParam } = minAndMax(candidates, getNumNonRestParameters);
+            const parameters: Symbol[] = [];
+            for (let i = 0; i < maxNonRestParam; i++) {
+                const symbols = mapDefined(candidates, ({ parameters, hasRestParameter }) => hasRestParameter ?
+                    i < parameters.length - 1 ? parameters[i] : last(parameters) :
+                    i < parameters.length ? parameters[i] : undefined);
+                Debug.assert(symbols.length !== 0);
+                parameters.push(createCombinedSymbolFromTypes(symbols, mapDefined(candidates, candidate => tryGetTypeAtPosition(candidate, i))));
+            }
+            const restParameterSymbols = mapDefined(candidates, c => c.hasRestParameter ? last(c.parameters) : undefined);
+            const hasRestParameter = restParameterSymbols.length !== 0;
+            if (hasRestParameter) {
+                const type = createArrayType(getUnionType(mapDefined(candidates, tryGetRestTypeOfSignature), UnionReduction.Subtype));
+                parameters.push(createCombinedSymbolForOverloadFailure(restParameterSymbols, type));
+            }
+            return createSignature(
+                candidates[0].declaration,
+                /*typeParameters*/ undefined, // Before calling this we tested for `!candidates.some(c => !!c.typeParameters)`.
+                thisParameter,
+                parameters,
+                /*resolvedReturnType*/ getIntersectionType(candidates.map(getReturnTypeOfSignature)),
+                /*typePredicate*/ undefined,
+                minArgumentCount,
+                hasRestParameter,
+                /*hasLiteralTypes*/ candidates.some(c => c.hasLiteralTypes));
+        }
+
+        function getNumNonRestParameters(signature: Signature): number {
+            const numParams = signature.parameters.length;
+            return signature.hasRestParameter ? numParams - 1 : numParams;
+        }
+
+        function createCombinedSymbolFromTypes(sources: ReadonlyArray<Symbol>, types: Type[]): Symbol {
+            return createCombinedSymbolForOverloadFailure(sources, getUnionType(types, UnionReduction.Subtype));
+        }
+
+        function createCombinedSymbolForOverloadFailure(sources: ReadonlyArray<Symbol>, type: Type): Symbol {
+            // This function is currently only used for erroneous overloads, so it's good enough to just use the first source.
+            return createSymbolWithType(first(sources), type);
+        }
+
+        function pickLongestCandidateSignature(node: CallLikeExpression, candidates: Signature[], args: ReadonlyArray<Expression>): Signature {
+            // Pick the longest signature. This way we can get a contextual type for cases like:
+            //     declare function f(a: { xa: number; xb: number; }, b: number);
+            //     f({ |
+            // Also, use explicitly-supplied type arguments if they are provided, so we can get a contextual signature in cases like:
+            //     declare function f<T>(k: keyof T);
+            //     f<Foo>("
+            const bestIndex = getLongestCandidateIndex(candidates, apparentArgumentCount === undefined ? args.length : apparentArgumentCount);
+            const candidate = candidates[bestIndex];
+            const { typeParameters } = candidate;
+            if (!typeParameters) {
+                return candidate;
+            }
+
+            const typeArgumentNodes: ReadonlyArray<TypeNode> = callLikeExpressionMayHaveTypeArguments(node) ? node.typeArguments || emptyArray : emptyArray;
+            const typeArguments = typeArgumentNodes.map(n => getTypeOfNode(n) || anyType);
+            while (typeArguments.length > typeParameters.length) {
+                typeArguments.pop();
+            }
+            while (typeArguments.length < typeParameters.length) {
+                typeArguments.push(getConstraintFromTypeParameter(typeParameters[typeArguments.length]) || getDefaultTypeArgumentType(isInJavaScriptFile(node)));
+            }
+            const instantiated = createSignatureInstantiation(candidate, typeArguments);
+            candidates[bestIndex] = instantiated;
+            return instantiated;
+        }
+
         function getLongestCandidateIndex(candidates: Signature[], argsCount: number): number {
             let maxParamsIndex = -1;
             let maxParams = -1;
@@ -19955,6 +20046,10 @@ namespace ts {
         }
 
         function getTypeAtPosition(signature: Signature, pos: number): Type {
+            return tryGetTypeAtPosition(signature, pos) || anyType;
+        }
+
+        function tryGetTypeAtPosition(signature: Signature, pos: number): Type | undefined {
             const paramCount = signature.parameters.length - (signature.hasRestParameter ? 1 : 0);
             if (pos < paramCount) {
                 return getTypeOfParameter(signature.parameters[pos]);
@@ -19970,9 +20065,9 @@ namespace ts {
                         return tupleRestType;
                     }
                 }
-                return getIndexTypeOfType(restType, IndexKind.Number) || anyType;
+                return getIndexTypeOfType(restType, IndexKind.Number);
             }
-            return anyType;
+            return undefined;
         }
 
         function getRestTypeAtPosition(source: Signature, pos: number): Type {
@@ -20453,15 +20548,20 @@ namespace ts {
             return type;
         }
 
+        function getReturnOrPromisedType(node: FunctionLikeDeclaration | MethodSignature, functionFlags: FunctionFlags) {
+            const returnTypeNode = getEffectiveReturnTypeNode(node);
+            return returnTypeNode &&
+                ((functionFlags & FunctionFlags.AsyncGenerator) === FunctionFlags.Async ?
+                 checkAsyncFunctionReturnType(node, returnTypeNode) : // Async function
+                 getTypeFromTypeNode(returnTypeNode)) || // AsyncGenerator function, Generator function, or normal function
+                getReturnTypeOfTypeTag(node); // type from JSDoc @type tag
+        }
+
         function checkFunctionExpressionOrObjectLiteralMethodDeferred(node: ArrowFunction | FunctionExpression | MethodDeclaration) {
             Debug.assert(node.kind !== SyntaxKind.MethodDeclaration || isObjectLiteralMethod(node));
 
             const functionFlags = getFunctionFlags(node);
-            const returnTypeNode = getEffectiveReturnTypeNode(node);
-            const returnOrPromisedType = returnTypeNode &&
-                ((functionFlags & FunctionFlags.AsyncGenerator) === FunctionFlags.Async ?
-                    checkAsyncFunctionReturnType(node) : // Async function
-                    getTypeFromTypeNode(returnTypeNode)); // AsyncGenerator function, Generator function, or normal function
+            const returnOrPromisedType = getReturnOrPromisedType(node, functionFlags);
 
             if ((functionFlags & FunctionFlags.Generator) === 0) { // Async function or normal function
                 // return is not necessary in the body of generators
@@ -20469,7 +20569,7 @@ namespace ts {
             }
 
             if (node.body) {
-                if (!returnTypeNode) {
+                if (!getEffectiveReturnTypeNode(node)) {
                     // There are some checks that are only performed in getReturnTypeFromBody, that may produce errors
                     // we need. An example is the noImplicitAny errors resulting from widening the return expression
                     // of a function. Because checking of function expression bodies is deferred, there was never an
@@ -21779,7 +21879,7 @@ namespace ts {
                     else {
                         const leadingError = () => chainDiagnosticMessages(/*details*/ undefined, Diagnostics.A_type_predicate_s_type_must_be_assignable_to_its_parameter_s_type);
                         checkTypeAssignableTo(typePredicate.type,
-                            getTypeOfNode(parent.parameters[typePredicate.parameterIndex])!, // TODO: GH#18217
+                            getTypeOfNode(parent.parameters[typePredicate.parameterIndex]),
                             node.type,
                             /*headMessage*/ undefined,
                             leadingError);
@@ -21921,7 +22021,7 @@ namespace ts {
                         }
                     }
                     else if ((functionFlags & FunctionFlags.AsyncGenerator) === FunctionFlags.Async) {
-                        checkAsyncFunctionReturnType(<FunctionLikeDeclaration>node);
+                        checkAsyncFunctionReturnType(<FunctionLikeDeclaration>node, returnTypeNode);
                     }
                 }
                 if (node.kind !== SyntaxKind.IndexSignature && node.kind !== SyntaxKind.JSDocFunctionType) {
@@ -22981,7 +23081,7 @@ namespace ts {
          *
          * @param node The signature to check
          */
-        function checkAsyncFunctionReturnType(node: FunctionLikeDeclaration | MethodSignature): Type {
+        function checkAsyncFunctionReturnType(node: FunctionLikeDeclaration | MethodSignature, returnTypeNode: TypeNode): Type {
             // As part of our emit for an async function, we will need to emit the entity name of
             // the return type annotation as an expression. To meet the necessary runtime semantics
             // for __awaiter, we must also check that the type of the declaration (e.g. the static
@@ -23006,7 +23106,6 @@ namespace ts {
             //      then<U>(...): Promise<U>;
             //  }
             //
-            const returnTypeNode = getEffectiveReturnTypeNode(node)!; // TODO: GH#18217
             const returnType = getTypeFromTypeNode(returnTypeNode);
 
             if (languageVersion >= ScriptTarget.ES2015) {
@@ -23111,7 +23210,7 @@ namespace ts {
                 case SyntaxKind.MethodDeclaration:
                 case SyntaxKind.GetAccessor:
                 case SyntaxKind.SetAccessor:
-                    const methodType = getTypeOfNode(node.parent)!; // TODO: GH#18217
+                    const methodType = getTypeOfNode(node.parent);
                     const descriptorType = createTypedPropertyDescriptorType(methodType);
                     expectedReturnType = getUnionType([descriptorType, voidType]);
                     break;
@@ -23416,15 +23515,12 @@ namespace ts {
             const body = node.kind === SyntaxKind.MethodSignature ? undefined : node.body;
             checkSourceElement(body);
 
-            const returnTypeNode = getEffectiveReturnTypeNode(node);
             if ((functionFlags & FunctionFlags.Generator) === 0) { // Async function or normal function
-                const returnOrPromisedType = returnTypeNode && (functionFlags & FunctionFlags.Async
-                    ? checkAsyncFunctionReturnType(node) // Async function
-                    : getTypeFromTypeNode(returnTypeNode)); // normal function
+                const returnOrPromisedType = getReturnOrPromisedType(node, functionFlags);
                 checkAllCodePathsInNonVoidFunctionReturnOrThrow(node, returnOrPromisedType);
             }
 
-            if (produceDiagnostics && !returnTypeNode) {
+            if (produceDiagnostics && !getEffectiveReturnTypeNode(node)) {
                 // Report an implicit any error if there is no body, no explicit return type, and node is not a private method
                 // in an ambient context
                 if (noImplicitAny && nodeIsMissing(body) && !isPrivateWithinAmbient(node)) {
@@ -23437,6 +23533,13 @@ namespace ts {
                     // yielded values. The only way to trigger these errors is to try checking its return type.
                     getReturnTypeOfSignature(getSignatureFromDeclaration(node));
                 }
+                // A js function declaration can have a @type tag instead of a return type node, but that type must have a call signature
+                if (isInJavaScriptFile(node)) {
+                    const typeTag = getJSDocTypeTag(node);
+                    if (typeTag && typeTag.typeExpression && !getSignaturesOfType(getTypeFromTypeNode(typeTag.typeExpression), SignatureKind.Call).length) {
+                        error(typeTag, Diagnostics.The_type_of_a_function_declaration_must_be_callable);
+                    }
+                }
             }
         }
 
@@ -24699,7 +24802,7 @@ namespace ts {
                         error(node, Diagnostics.Return_type_of_constructor_signature_must_be_assignable_to_the_instance_type_of_the_class);
                     }
                 }
-                else if (getEffectiveReturnTypeNode(func) || isGetAccessorWithAnnotatedSetAccessor(func)) {
+                else if (getEffectiveReturnTypeNode(func) || isGetAccessorWithAnnotatedSetAccessor(func) || getReturnTypeOfTypeTag(func)) {
                     if (functionFlags & FunctionFlags.Async) { // Async function
                         const promisedType = getPromisedTypeOfPromise(returnType);
                         const awaitedType = checkAwaitedType(exprType, node, Diagnostics.The_return_type_of_an_async_function_must_either_be_a_valid_promise_or_must_not_contain_a_callable_then_member);
@@ -27050,7 +27153,7 @@ namespace ts {
                 resolveEntityName(node.propertyName || node.name, SymbolFlags.Value | SymbolFlags.Type | SymbolFlags.Namespace | SymbolFlags.Alias);
         }
 
-        function getTypeOfNode(node: Node): Type | undefined {
+        function getTypeOfNode(node: Node): Type {
             if (node.flags & NodeFlags.InWithStatement) {
                 // We cannot answer semantic questions within a with block, do not proceed any further
                 return errorType;
@@ -27089,7 +27192,7 @@ namespace ts {
 
             if (isTypeDeclarationName(node)) {
                 const symbol = getSymbolAtLocation(node);
-                return symbol && getDeclaredTypeOfSymbol(symbol);
+                return symbol ? getDeclaredTypeOfSymbol(symbol) : errorType;
             }
 
             if (isDeclaration(node)) {
@@ -27100,11 +27203,11 @@ namespace ts {
 
             if (isDeclarationNameOrImportPropertyName(node)) {
                 const symbol = getSymbolAtLocation(node);
-                return symbol && getTypeOfSymbol(symbol);
+                return symbol ? getTypeOfSymbol(symbol) : errorType;
             }
 
             if (isBindingPattern(node)) {
-                return getTypeForVariableLikeDeclaration(node.parent, /*includeOptionality*/ true);
+                return getTypeForVariableLikeDeclaration(node.parent, /*includeOptionality*/ true) || errorType;
             }
 
             if (isInRightSideOfImportOrExportAssignment(<Identifier>node)) {

src/compiler/core.ts

@@ -1866,6 +1866,9 @@ namespace ts {
             if (candidateName !== undefined && Math.abs(candidateName.length - nameLowerCase.length) <= maximumLengthDifference) {
                 const candidateNameLowerCase = candidateName.toLowerCase();
                 if (candidateNameLowerCase === nameLowerCase) {
+                    if (candidateName === name) {
+                        continue;
+                    }
                     return candidate;
                 }
                 if (justCheckExactMatches) {

src/compiler/diagnosticMessages.json

@@ -2056,6 +2056,10 @@
         "category": "Error",
         "code": 2574
     },
+    "No overload expects {0} arguments, but overloads do exist that expect either {1} or {2} arguments.": {
+        "category": "Error",
+        "code": 2575
+    },
     "JSX element attributes type '{0}' may not be a union type.": {
         "category": "Error",
         "code": 2600
@@ -4017,6 +4021,10 @@
         "category": "Error",
         "code": 8029
     },
+    "The type of a function declaration must be callable.": {
+        "category": "Error",
+        "code": 8030
+    },
     "Only identifiers/qualified-names with optional type arguments are currently supported in a class 'extends' clause.": {
         "category": "Error",
         "code": 9002

src/compiler/symbolWalker.ts

@@ -171,8 +171,8 @@ namespace ts {
                 }
                 const t = getTypeOfSymbol(symbol);
                 visitType(t); // Should handle members on classes and such
-                if (symbol.flags & SymbolFlags.HasExports) {
-                    symbol.exports!.forEach(visitSymbol);
+                if (symbol.exports) {
+                    symbol.exports.forEach(visitSymbol);
                 }
                 forEach(symbol.declarations, d => {
                     // Type queries are too far resolved when we just visit the symbol's type

src/compiler/transformers/es2015.ts

@@ -529,7 +529,7 @@ namespace ts {
                     createVariableStatement(/*modifiers*/ undefined,
                         createVariableDeclarationList(taggedTemplateStringDeclarations)));
             }
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
             exitSubtree(ancestorFacts, HierarchyFacts.None, HierarchyFacts.None);
             return updateSourceFileNode(
                 node,
@@ -837,7 +837,7 @@ namespace ts {
             setEmitFlags(statement, EmitFlags.NoComments | EmitFlags.NoTokenSourceMaps);
             statements.push(statement);
 
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
 
             const block = createBlock(setTextRange(createNodeArray(statements), /*location*/ node.members), /*multiLine*/ true);
             setEmitFlags(block, EmitFlags.NoComments);
@@ -980,7 +980,7 @@ namespace ts {
                 );
             }
 
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
 
             if (constructor) {
                 prependCaptureNewTargetIfNeeded(statements, constructor, /*copyOnWrite*/ false);
@@ -1892,7 +1892,7 @@ namespace ts {
             }
 
             const lexicalEnvironment = context.endLexicalEnvironment();
-            prependStatements(statements, lexicalEnvironment);
+            addStatementsAfterPrologue(statements, lexicalEnvironment);
             prependCaptureNewTargetIfNeeded(statements, node, /*copyOnWrite*/ false);
 
             // If we added any final generated statements, this must be a multi-line block
@@ -2707,7 +2707,7 @@ namespace ts {
                 if (loopOutParameters.length) {
                     copyOutParameters(loopOutParameters, CopyDirection.ToOutParameter, statements);
                 }
-                prependStatements(statements, lexicalEnvironment);
+                addStatementsAfterPrologue(statements, lexicalEnvironment);
                 loopBody = createBlock(statements, /*multiline*/ true);
             }
 

src/compiler/transformers/es2017.ts

@@ -413,7 +413,7 @@ namespace ts {
                     )
                 );
 
-                prependStatements(statements, endLexicalEnvironment());
+                addStatementsAfterPrologue(statements, endLexicalEnvironment());
 
                 const block = createBlock(statements, /*multiLine*/ true);
                 setTextRange(block, node.body);

src/compiler/transformers/esnext.ts

@@ -675,7 +675,7 @@ namespace ts {
                 )
             );
 
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
             const block = updateBlock(node.body!, statements);
 
             // Minor optimization, emit `_super` helper to capture `super` access in an arrow.
@@ -707,7 +707,7 @@ namespace ts {
             const leadingStatements = endLexicalEnvironment();
             if (statementOffset > 0 || some(statements) || some(leadingStatements)) {
                 const block = convertToFunctionBody(body, /*multiLine*/ true);
-                prependStatements(statements, leadingStatements);
+                addStatementsAfterPrologue(statements, leadingStatements);
                 addRange(statements, block.statements.slice(statementOffset));
                 return updateBlock(block, setTextRange(createNodeArray(statements), block.statements));
             }

src/compiler/transformers/generators.ts

@@ -587,7 +587,7 @@ namespace ts {
             transformAndEmitStatements(body.statements, statementOffset);
 
             const buildResult = build();
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
             statements.push(createReturn(buildResult));
 
             // Restore previous generator state

src/compiler/transformers/module/module.ts

@@ -97,7 +97,7 @@ namespace ts {
             append(statements, visitNode(currentModuleInfo.externalHelpersImportDeclaration, sourceElementVisitor, isStatement));
             addRange(statements, visitNodes(node.statements, sourceElementVisitor, isStatement, statementOffset));
             addExportEqualsIfNeeded(statements, /*emitAsReturn*/ false);
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
 
             const updated = updateSourceFileNode(node, setTextRange(createNodeArray(statements), node.statements));
             if (currentModuleInfo.hasExportStarsToExportValues && !compilerOptions.importHelpers) {
@@ -426,7 +426,7 @@ namespace ts {
 
             // End the lexical environment for the module body
             // and merge any new lexical declarations.
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
 
             const body = createBlock(statements, /*multiLine*/ true);
             if (currentModuleInfo.hasExportStarsToExportValues && !compilerOptions.importHelpers) {

src/compiler/transformers/module/system.ts

@@ -257,7 +257,7 @@ namespace ts {
             // We emit hoisted variables early to align roughly with our previous emit output.
             // Two key differences in this approach are:
             // - Temporary variables will appear at the top rather than at the bottom of the file
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
 
             const exportStarFunction = addExportStarIfNeeded(statements)!; // TODO: GH#18217
             const moduleObject = createObjectLiteral([

src/compiler/transformers/ts.ts

@@ -682,7 +682,7 @@ namespace ts {
                 setEmitFlags(statement, EmitFlags.NoComments | EmitFlags.NoTokenSourceMaps);
                 statements.push(statement);
 
-                prependStatements(statements, context.endLexicalEnvironment());
+                addStatementsAfterPrologue(statements, context.endLexicalEnvironment());
 
                 const iife = createImmediatelyInvokedArrowFunction(statements);
                 setEmitFlags(iife, EmitFlags.TypeScriptClassWrapper);
@@ -2711,7 +2711,7 @@ namespace ts {
             const statements: Statement[] = [];
             startLexicalEnvironment();
             const members = map(node.members, transformEnumMember);
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
             addRange(statements, members);
 
             currentNamespaceContainerName = savedCurrentNamespaceLocalName;
@@ -3026,7 +3026,7 @@ namespace ts {
                 statementsLocation = moveRangePos(moduleBlock.statements, -1);
             }
 
-            prependStatements(statements, endLexicalEnvironment());
+            addStatementsAfterPrologue(statements, endLexicalEnvironment());
             currentNamespaceContainerName = savedCurrentNamespaceContainerName;
             currentNamespace = savedCurrentNamespace;
             currentScopeFirstDeclarationsOfName = savedCurrentScopeFirstDeclarationsOfName;

src/compiler/types.ts

@@ -2936,7 +2936,7 @@ namespace ts {
          */
         getExportSymbolOfSymbol(symbol: Symbol): Symbol;
         getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol | undefined;
-        getTypeAtLocation(node: Node): Type | undefined;
+        getTypeAtLocation(node: Node): Type;
         getTypeFromTypeNode(node: TypeNode): Type;
 
         signatureToString(signature: Signature, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): string;
@@ -3439,9 +3439,6 @@ namespace ts {
 
         ExportHasLocal = Function | Class | Enum | ValueModule,
 
-        HasExports = Class | Enum | Module | Variable,
-        HasMembers = Class | Interface | TypeLiteral | ObjectLiteral,
-
         BlockScoped = BlockScopedVariable | Class | Enum,
 
         PropertyOrAccessor = Property | Accessor,

src/compiler/utilities.ts

@@ -401,21 +401,18 @@ namespace ts {
     }
 
     /**
-     * Appends a range of value to begin of an array, returning the array.
-     *
-     * @param to The array to which `value` is to be appended. If `to` is `undefined`, a new array
-     * is created if `value` was appended.
-     * @param from The values to append to the array. If `from` is `undefined`, nothing is
-     * appended. If an element of `from` is `undefined`, that element is not appended.
+     * Prepends statements to an array while taking care of prologue directives.
      */
-    export function prependStatements<T extends Statement>(to: T[], from: ReadonlyArray<T> | undefined): T[] | undefined {
+    export function addStatementsAfterPrologue<T extends Statement>(to: T[], from: ReadonlyArray<T> | undefined): T[] {
         if (from === undefined || from.length === 0) return to;
-        if (to === undefined) return from.slice();
-        const prologue = to.length && isPrologueDirective(to[0]) && to.shift();
-        to.unshift(...from);
-        if (prologue) {
-            to.unshift(prologue);
+        let statementIndex = 0;
+        // skip all prologue directives to insert at the correct position
+        for (; statementIndex < to.length; ++statementIndex) {
+            if (!isPrologueDirective(to[statementIndex])) {
+                break;
+            }
         }
+        to.splice(statementIndex, 0, ...from);
         return to;
     }
 
@@ -912,9 +909,7 @@ namespace ts {
     }
 
     export function isLiteralImportTypeNode(n: Node): n is LiteralImportTypeNode {
-        return n.kind === SyntaxKind.ImportType &&
-            (n as ImportTypeNode).argument.kind === SyntaxKind.LiteralType &&
-            isStringLiteral(((n as ImportTypeNode).argument as LiteralTypeNode).literal);
+        return isImportTypeNode(n) && isLiteralTypeNode(n.argument) && isStringLiteral(n.argument.literal);
     }
 
     export function isPrologueDirective(node: Node): node is PrologueDirective {
@@ -8090,4 +8085,20 @@ namespace ts {
         Debug.assert(index !== -1);
         return arr.slice(index);
     }
+
+    export function minAndMax<T>(arr: ReadonlyArray<T>, getValue: (value: T) => number): { readonly min: number, readonly max: number } {
+        Debug.assert(arr.length !== 0);
+        let min = getValue(arr[0]);
+        let max = min;
+        for (let i = 1; i < arr.length; i++) {
+            const value = getValue(arr[i]);
+            if (value < min) {
+                min = value;
+            }
+            else if (value > max) {
+                max = value;
+            }
+        }
+        return { min, max };
+    }
 }

src/compiler/visitor.ts

@@ -1476,8 +1476,8 @@ namespace ts {
         }
 
         return isNodeArray(statements)
-            ? setTextRange(createNodeArray(prependStatements(statements.slice(), declarations)), statements)
-            : prependStatements(statements, declarations);
+            ? setTextRange(createNodeArray(addStatementsAfterPrologue(statements.slice(), declarations)), statements)
+            : addStatementsAfterPrologue(statements, declarations);
     }
 
     /**

src/harness/fourslash.ts

@@ -4767,7 +4767,7 @@ namespace FourSlashInterface {
     }
 
     export interface VerifyCompletionsOptions {
-        readonly marker?: ArrayOrSingle<string>;
+        readonly marker?: ArrayOrSingle<string | FourSlash.Marker>;
         readonly isNewIdentifierLocation?: boolean;
         readonly exact?: ArrayOrSingle<ExpectedCompletionEntry>;
         readonly includes?: ArrayOrSingle<ExpectedCompletionEntry>;

src/services/codefixes/fixAddMissingMember.ts

@@ -124,7 +124,7 @@ namespace ts.codefix {
         const { parent } = token;
         if (!isPropertyAccessExpression(parent)) return undefined;
 
-        const leftExpressionType = skipConstraint(checker.getTypeAtLocation(parent.expression)!);
+        const leftExpressionType = skipConstraint(checker.getTypeAtLocation(parent.expression));
         const { symbol } = leftExpressionType;
         if (!symbol || !symbol.declarations) return undefined;
 
@@ -183,7 +183,7 @@ namespace ts.codefix {
         if (token.parent.parent.kind === SyntaxKind.BinaryExpression) {
             const binaryExpression = token.parent.parent as BinaryExpression;
             const otherExpression = token.parent === binaryExpression.left ? binaryExpression.right : binaryExpression.left;
-            const widenedType = checker.getWidenedType(checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(otherExpression)!)); // TODO: GH#18217
+            const widenedType = checker.getWidenedType(checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(otherExpression)));
             typeNode = checker.typeToTypeNode(widenedType, classDeclaration);
         }
         return typeNode || createKeywordTypeNode(SyntaxKind.AnyKeyword);

src/services/codefixes/fixClassDoesntImplementInheritedAbstractMember.ts

@@ -34,7 +34,7 @@ namespace ts.codefix {
 
     function addMissingMembers(classDeclaration: ClassLikeDeclaration, sourceFile: SourceFile, checker: TypeChecker, changeTracker: textChanges.ChangeTracker, preferences: UserPreferences): void {
         const extendsNode = getEffectiveBaseTypeNode(classDeclaration)!;
-        const instantiatedExtendsType = checker.getTypeAtLocation(extendsNode)!;
+        const instantiatedExtendsType = checker.getTypeAtLocation(extendsNode);
 
         // Note that this is ultimately derived from a map indexed by symbol names,
         // so duplicates cannot occur.

src/services/codefixes/fixClassIncorrectlyImplementsInterface.ts

@@ -51,7 +51,7 @@ namespace ts.codefix {
         const implementedTypeSymbols = checker.getPropertiesOfType(implementedType);
         const nonPrivateAndNotExistedInHeritageClauseMembers = implementedTypeSymbols.filter(and(symbolPointsToNonPrivateMember, symbol => !maybeHeritageClauseSymbol.has(symbol.escapedName)));
 
-        const classType = checker.getTypeAtLocation(classDeclaration)!;
+        const classType = checker.getTypeAtLocation(classDeclaration);
 
         if (!classType.getNumberIndexType()) {
             createMissingIndexSignatureDeclaration(implementedType, IndexKind.Number);

src/services/codefixes/fixInvalidImportSyntax.ts

@@ -77,7 +77,7 @@ namespace ts.codefix {
     }
 
     function getImportCodeFixesForExpression(context: CodeFixContext, expr: Node): CodeFixAction[] | undefined {
-        const type = context.program.getTypeChecker().getTypeAtLocation(expr)!; // TODO: GH#18217
+        const type = context.program.getTypeChecker().getTypeAtLocation(expr);
         if (!(type.symbol && (type.symbol as TransientSymbol).originatingImport)) {
             return [];
         }

src/services/codefixes/fixSpelling.ts

@@ -35,7 +35,7 @@ namespace ts.codefix {
         let suggestion: string | undefined;
         if (isPropertyAccessExpression(node.parent) && node.parent.name === node) {
             Debug.assert(node.kind === SyntaxKind.Identifier);
-            const containingType = checker.getTypeAtLocation(node.parent.expression)!;
+            const containingType = checker.getTypeAtLocation(node.parent.expression);
             suggestion = checker.getSuggestionForNonexistentProperty(node as Identifier, containingType);
         }
         else if (isImportSpecifier(node.parent) && node.parent.name === node) {

src/services/codefixes/inferFromUsage.ts

@@ -401,7 +401,7 @@ namespace ts.codefix {
                 case SyntaxKind.LessThanEqualsToken:
                 case SyntaxKind.GreaterThanToken:
                 case SyntaxKind.GreaterThanEqualsToken:
-                    const operandType = checker.getTypeAtLocation(parent.left === node ? parent.right : parent.left)!;
+                    const operandType = checker.getTypeAtLocation(parent.left === node ? parent.right : parent.left);
                     if (operandType.flags & TypeFlags.EnumLike) {
                         addCandidateType(usageContext, operandType);
                     }
@@ -412,7 +412,7 @@ namespace ts.codefix {
 
                 case SyntaxKind.PlusEqualsToken:
                 case SyntaxKind.PlusToken:
-                    const otherOperandType = checker.getTypeAtLocation(parent.left === node ? parent.right : parent.left)!;
+                    const otherOperandType = checker.getTypeAtLocation(parent.left === node ? parent.right : parent.left);
                     if (otherOperandType.flags & TypeFlags.EnumLike) {
                         addCandidateType(usageContext, otherOperandType);
                     }
@@ -472,7 +472,7 @@ namespace ts.codefix {
 
             if (parent.arguments) {
                 for (const argument of parent.arguments) {
-                    callContext.argumentTypes.push(checker.getTypeAtLocation(argument)!);
+                    callContext.argumentTypes.push(checker.getTypeAtLocation(argument));
                 }
             }
 
@@ -501,7 +501,7 @@ namespace ts.codefix {
                 return;
             }
             else {
-                const indexType = checker.getTypeAtLocation(parent)!;
+                const indexType = checker.getTypeAtLocation(parent);
                 const indexUsageContext = {};
                 inferTypeFromContext(parent, checker, indexUsageContext);
                 if (indexType.flags & TypeFlags.NumberLike) {

src/services/completions.ts

@@ -1060,7 +1060,7 @@ namespace ts.Completions {
             const isImportType = isLiteralImportTypeNode(node);
             const isTypeLocation = insideJsDocTagTypeExpression || (isImportType && !(node as ImportTypeNode).isTypeOf) || isPartOfTypeNode(node.parent);
             const isRhsOfImportDeclaration = isInRightSideOfInternalImportEqualsDeclaration(node);
-            const allowTypeOrValue = isRhsOfImportDeclaration || (!isTypeLocation && isPossiblyTypeArgumentPosition(contextToken, sourceFile));
+            const allowTypeOrValue = isRhsOfImportDeclaration || (!isTypeLocation && isPossiblyTypeArgumentPosition(contextToken, sourceFile, typeChecker));
             if (isEntityName(node) || isImportType) {
                 let symbol = typeChecker.getSymbolAtLocation(node);
                 if (symbol) {
@@ -1098,7 +1098,7 @@ namespace ts.Completions {
             }
 
             if (!isTypeLocation) {
-                addTypeProperties(typeChecker.getTypeAtLocation(node)!);
+                addTypeProperties(typeChecker.getTypeAtLocation(node));
             }
         }
 
@@ -1275,7 +1275,7 @@ namespace ts.Completions {
 
         function filterGlobalCompletion(symbols: Symbol[]): void {
             const isTypeOnlyCompletion = insideJsDocTagTypeExpression || !isContextTokenValueLocation(contextToken) && (isPartOfTypeNode(location) || isContextTokenTypeLocation(contextToken));
-            const allowTypes = isTypeOnlyCompletion || !isContextTokenValueLocation(contextToken) && isPossiblyTypeArgumentPosition(contextToken, sourceFile);
+            const allowTypes = isTypeOnlyCompletion || !isContextTokenValueLocation(contextToken) && isPossiblyTypeArgumentPosition(contextToken, sourceFile, typeChecker);
             if (isTypeOnlyCompletion) keywordFilters = KeywordCompletionFilters.TypeKeywords;
 
             filterMutate(symbols, symbol => {

src/services/goToDefinition.ts

@@ -171,7 +171,7 @@ namespace ts.GoToDefinition {
     // At 'x.foo', see if the type of 'x' has an index signature, and if so find its declarations.
     function getDefinitionInfoForIndexSignatures(node: Node, checker: TypeChecker): DefinitionInfo[] | undefined {
         if (!isPropertyAccessExpression(node.parent) || node.parent.name !== node) return;
-        const type = checker.getTypeAtLocation(node.parent.expression)!;
+        const type = checker.getTypeAtLocation(node.parent.expression);
         return mapDefined(type.isUnionOrIntersection() ? type.types : [type], nonUnionType => {
             const info = checker.getIndexInfoOfType(nonUnionType, IndexKind.String);
             return info && info.declaration && createDefinitionFromSignatureDeclaration(checker, info.declaration);

src/services/refactors/extractSymbol.ts

@@ -866,7 +866,7 @@ namespace ts.refactor.extractSymbol {
 
                     // Being returned through an object literal will have widened the type.
                     const variableType: TypeNode | undefined = checker.typeToTypeNode(
-                        checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(variableDeclaration)!), // TODO: GH#18217
+                        checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(variableDeclaration)),
                         scope,
                         NodeBuilderFlags.NoTruncation);
 
@@ -1406,7 +1406,7 @@ namespace ts.refactor.extractSymbol {
             const end = last(statements).end;
             expressionDiagnostic = createFileDiagnostic(sourceFile, start, end - start, Messages.expressionExpected);
         }
-        else if (checker.getTypeAtLocation(expression)!.flags & (TypeFlags.Void | TypeFlags.Never)) { // TODO: GH#18217
+        else if (checker.getTypeAtLocation(expression).flags & (TypeFlags.Void | TypeFlags.Never)) {
             expressionDiagnostic = createDiagnosticForNode(expression, Messages.uselessConstantType);
         }
 
@@ -1555,7 +1555,7 @@ namespace ts.refactor.extractSymbol {
 
         function collectUsages(node: Node, valueUsage = Usage.Read) {
             if (inGenericContext) {
-                const type = checker.getTypeAtLocation(node)!; // TODO: GH#18217
+                const type = checker.getTypeAtLocation(node);
                 recordTypeParameterUsages(type);
             }
 

src/services/signatureHelp.ts

@@ -103,9 +103,7 @@ namespace ts.SignatureHelp {
             if (onlyUseSyntacticOwners && !lessThanFollowsCalledExpression(startingToken, sourceFile, invocation.called)) {
                 return undefined;
             }
-            const type = checker.getTypeAtLocation(invocation.called)!; // TODO: GH#18217
-            const signatures = isNewExpression(invocation.called.parent) ? type.getConstructSignatures() : type.getCallSignatures();
-            const candidates = signatures.filter(candidate => !!candidate.typeParameters && candidate.typeParameters.length >= argumentInfo.argumentCount);
+            const candidates = getPossibleGenericSignatures(invocation.called, argumentInfo.argumentCount, checker);
             return candidates.length === 0 ? undefined : { candidates, resolvedSignature: first(candidates) };
         }
         else {
@@ -261,7 +259,7 @@ namespace ts.SignatureHelp {
             };
         }
         else {
-            const typeArgInfo = isPossiblyTypeArgumentPosition(node, sourceFile);
+            const typeArgInfo = getPossibleTypeArgumentsInfo(node, sourceFile);
             if (typeArgInfo) {
                 const { called, nTypeArguments } = typeArgInfo;
                 const invocation: Invocation = { kind: InvocationKind.TypeArgs, called };

src/services/symbolDisplay.ts

@@ -172,7 +172,7 @@ namespace ts.SymbolDisplay {
 
                 const useConstructSignatures = callExpressionLike.kind === SyntaxKind.NewExpression || (isCallExpression(callExpressionLike) && callExpressionLike.expression.kind === SyntaxKind.SuperKeyword);
 
-                const allSignatures = useConstructSignatures ? type!.getConstructSignatures() : type!.getCallSignatures();
+                const allSignatures = useConstructSignatures ? type.getConstructSignatures() : type.getCallSignatures();
 
                 if (!contains(allSignatures, signature.target) && !contains(allSignatures, signature)) {
                     // Get the first signature if there is one -- allSignatures may contain
@@ -184,7 +184,7 @@ namespace ts.SymbolDisplay {
                     if (useConstructSignatures && (symbolFlags & SymbolFlags.Class)) {
                         // Constructor
                         symbolKind = ScriptElementKind.constructorImplementationElement;
-                        addPrefixForAnyFunctionOrVar(type!.symbol, symbolKind);
+                        addPrefixForAnyFunctionOrVar(type.symbol, symbolKind);
                     }
                     else if (symbolFlags & SymbolFlags.Alias) {
                         symbolKind = ScriptElementKind.alias;
@@ -211,8 +211,8 @@ namespace ts.SymbolDisplay {
                             // If it is call or construct signature of lambda's write type name
                             displayParts.push(punctuationPart(SyntaxKind.ColonToken));
                             displayParts.push(spacePart());
-                            if (!(getObjectFlags(type!) & ObjectFlags.Anonymous) && type!.symbol) {
-                                addRange(displayParts, symbolToDisplayParts(typeChecker, type!.symbol, enclosingDeclaration, /*meaning*/ undefined, SymbolFormatFlags.AllowAnyNodeKind | SymbolFormatFlags.WriteTypeParametersOrArguments));
+                            if (!(getObjectFlags(type) & ObjectFlags.Anonymous) && type.symbol) {
+                                addRange(displayParts, symbolToDisplayParts(typeChecker, type.symbol, enclosingDeclaration, /*meaning*/ undefined, SymbolFormatFlags.AllowAnyNodeKind | SymbolFormatFlags.WriteTypeParametersOrArguments));
                                 displayParts.push(lineBreakPart());
                             }
                             if (useConstructSignatures) {
@@ -238,7 +238,7 @@ namespace ts.SymbolDisplay {
                     declaration === (location.kind === SyntaxKind.ConstructorKeyword ? functionDeclaration.parent : functionDeclaration));
 
                 if (locationIsSymbolDeclaration) {
-                    const allSignatures = functionDeclaration.kind === SyntaxKind.Constructor ? type!.getNonNullableType().getConstructSignatures() : type!.getNonNullableType().getCallSignatures();
+                    const allSignatures = functionDeclaration.kind === SyntaxKind.Constructor ? type.getNonNullableType().getConstructSignatures() : type.getNonNullableType().getCallSignatures();
                     if (!typeChecker.isImplementationOfOverload(functionDeclaration)) {
                         signature = typeChecker.getSignatureFromDeclaration(functionDeclaration)!; // TODO: GH#18217
                     }
@@ -249,12 +249,12 @@ namespace ts.SymbolDisplay {
                     if (functionDeclaration.kind === SyntaxKind.Constructor) {
                         // show (constructor) Type(...) signature
                         symbolKind = ScriptElementKind.constructorImplementationElement;
-                        addPrefixForAnyFunctionOrVar(type!.symbol, symbolKind);
+                        addPrefixForAnyFunctionOrVar(type.symbol, symbolKind);
                     }
                     else {
                         // (function/method) symbol(..signature)
                         addPrefixForAnyFunctionOrVar(functionDeclaration.kind === SyntaxKind.CallSignature &&
-                            !(type!.symbol.flags & SymbolFlags.TypeLiteral || type!.symbol.flags & SymbolFlags.ObjectLiteral) ? type!.symbol : symbol, symbolKind);
+                            !(type.symbol.flags & SymbolFlags.TypeLiteral || type.symbol.flags & SymbolFlags.ObjectLiteral) ? type.symbol : symbol, symbolKind);
                     }
 
                     addSignatureDisplayParts(signature, allSignatures);

src/services/textChanges.ts

@@ -1053,18 +1053,29 @@ namespace ts.textChanges {
                     break;
 
                 case SyntaxKind.TypeParameter: {
-                    const typeParameters = getEffectiveTypeParameterDeclarations(<DeclarationWithTypeParameters>node.parent);
-                    if (typeParameters.length === 1) {
-                        const { pos, end } = cast(typeParameters, isNodeArray);
-                        const previousToken = getTokenAtPosition(sourceFile, pos - 1);
-                        const nextToken = getTokenAtPosition(sourceFile, end);
-                        Debug.assert(previousToken.kind === SyntaxKind.LessThanToken);
-                        Debug.assert(nextToken.kind === SyntaxKind.GreaterThanToken);
+                    const typeParam = node as TypeParameterDeclaration;
+                    switch (typeParam.parent.kind) {
+                        case SyntaxKind.JSDocTemplateTag:
+                            changes.deleteRange(sourceFile, getRangeToDeleteJsDocTag(typeParam.parent, sourceFile));
+                            break;
+                        case SyntaxKind.InferType:
+                            // TODO: GH#25594
+                            break;
+                        default: {
+                            const typeParameters = getEffectiveTypeParameterDeclarations(typeParam.parent);
+                            if (typeParameters.length === 1) {
+                                const { pos, end } = cast(typeParameters, isNodeArray);
+                                const previousToken = getTokenAtPosition(sourceFile, pos - 1);
+                                const nextToken = getTokenAtPosition(sourceFile, end);
+                                Debug.assert(previousToken.kind === SyntaxKind.LessThanToken);
+                                Debug.assert(nextToken.kind === SyntaxKind.GreaterThanToken);
 
-                        changes.deleteNodeRange(sourceFile, previousToken, nextToken);
-                    }
-                    else {
-                        deleteNodeInList(changes, deletedNodesInLists, sourceFile, node);
+                                changes.deleteNodeRange(sourceFile, previousToken, nextToken);
+                            }
+                            else {
+                                deleteNodeInList(changes, deletedNodesInLists, sourceFile, node);
+                            }
+                        }
                     }
                     break;
                 }
@@ -1166,6 +1177,12 @@ namespace ts.textChanges {
                     Debug.assertNever(gp);
             }
         }
+
+        function getRangeToDeleteJsDocTag(node: JSDocTag, sourceFile: SourceFile): TextRange {
+            const { parent } = node;
+            const toDelete = parent.kind === SyntaxKind.JSDocComment && parent.comment === undefined && parent.tags!.length === 1 ? parent : node;
+            return createTextRangeFromNode(toDelete, sourceFile);
+        }
     }
 
     /** Warning: This deletes comments too. See `copyComments` in `convertFunctionToEs6Class`. */

src/services/utilities.ts

@@ -917,11 +917,25 @@ namespace ts {
         }
     }
 
+    export function isPossiblyTypeArgumentPosition(token: Node, sourceFile: SourceFile, checker: TypeChecker): boolean {
+        const info = getPossibleTypeArgumentsInfo(token, sourceFile);
+        return info !== undefined && (isPartOfTypeNode(info.called) ||
+            getPossibleGenericSignatures(info.called, info.nTypeArguments, checker).length !== 0 ||
+            isPossiblyTypeArgumentPosition(info.called, sourceFile, checker));
+    }
+
+    export function getPossibleGenericSignatures(called: Expression, typeArgumentCount: number, checker: TypeChecker): ReadonlyArray<Signature> {
+        const type = checker.getTypeAtLocation(called);
+        const signatures = isNewExpression(called.parent) ? type.getConstructSignatures() : type.getCallSignatures();
+        return signatures.filter(candidate => !!candidate.typeParameters && candidate.typeParameters.length >= typeArgumentCount);
+    }
+
     export interface PossibleTypeArgumentInfo {
         readonly called: Identifier;
         readonly nTypeArguments: number;
     }
-    export function isPossiblyTypeArgumentPosition(tokenIn: Node, sourceFile: SourceFile): PossibleTypeArgumentInfo | undefined {
+    // Get info for an expression like `f <` that may be the start of type arguments.
+    export function getPossibleTypeArgumentsInfo(tokenIn: Node, sourceFile: SourceFile): PossibleTypeArgumentInfo | undefined {
         let token: Node | undefined = tokenIn;
         // This function determines if the node could be type argument position
         // Since during editing, when type argument list is not complete,
@@ -1146,6 +1160,10 @@ namespace ts {
         return createTextSpanFromBounds(node.getStart(sourceFile), node.getEnd());
     }
 
+    export function createTextRangeFromNode(node: Node, sourceFile: SourceFile): TextRange {
+        return createTextRange(node.getStart(sourceFile), node.end);
+    }
+
     export function createTextSpanFromRange(range: TextRange): TextSpan {
         return createTextSpanFromBounds(range.pos, range.end);
     }

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -1901,7 +1901,7 @@ declare namespace ts {
          */
         getExportSymbolOfSymbol(symbol: Symbol): Symbol;
         getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol | undefined;
-        getTypeAtLocation(node: Node): Type | undefined;
+        getTypeAtLocation(node: Node): Type;
         getTypeFromTypeNode(node: TypeNode): Type;
         signatureToString(signature: Signature, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): string;
         typeToString(type: Type, enclosingDeclaration?: Node, flags?: TypeFormatFlags): string;
@@ -2075,8 +2075,6 @@ declare namespace ts {
         AliasExcludes = 2097152,
         ModuleMember = 2623475,
         ExportHasLocal = 944,
-        HasExports = 1955,
-        HasMembers = 6240,
         BlockScoped = 418,
         PropertyOrAccessor = 98308,
         ClassMember = 106500

tests/baselines/reference/api/typescript.d.ts

@@ -1901,7 +1901,7 @@ declare namespace ts {
          */
         getExportSymbolOfSymbol(symbol: Symbol): Symbol;
         getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol | undefined;
-        getTypeAtLocation(node: Node): Type | undefined;
+        getTypeAtLocation(node: Node): Type;
         getTypeFromTypeNode(node: TypeNode): Type;
         signatureToString(signature: Signature, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): string;
         typeToString(type: Type, enclosingDeclaration?: Node, flags?: TypeFormatFlags): string;
@@ -2075,8 +2075,6 @@ declare namespace ts {
         AliasExcludes = 2097152,
         ModuleMember = 2623475,
         ExportHasLocal = 944,
-        HasExports = 1955,
-        HasMembers = 6240,
         BlockScoped = 418,
         PropertyOrAccessor = 98308,
         ClassMember = 106500

tests/baselines/reference/callbackTag2.types

@@ -43,7 +43,7 @@ var outside = n => n + 1;
 /** @type {Final<{ fantasy }, { heroes }>} */
 var noreturn = (barts, tidus, noctis) => "cecil"
 >noreturn : Final<{ fantasy: any; }, { heroes: any; }>
->(barts, tidus, noctis) => "cecil" : (barts: { fantasy: any; }, tidus: { heroes: any; }, noctis: { heroes: any; } & { fantasy: any; }) => "cecil"
+>(barts, tidus, noctis) => "cecil" : (barts: { fantasy: any; }, tidus: { heroes: any; }, noctis: { heroes: any; } & { fantasy: any; }) => "cecil" | "zidane"
 >barts : { fantasy: any; }
 >tidus : { heroes: any; }
 >noctis : { heroes: any; } & { fantasy: any; }

tests/baselines/reference/callbackTagNamespace.types

@@ -11,7 +11,7 @@ var x = 1;
 
 /** @type {NS.Nested.Inner} */
 function f(space, peace) {
->f : (space: any, peace: any) => string
+>f : (space: any, peace: any) => string | number
 >space : any
 >peace : any
 

tests/baselines/reference/checkJsdocTypeTag1.types

@@ -61,7 +61,7 @@ y(1);
 /** @type {function (number)} */
 const x1 = (a) => a + 1;
 >x1 : (arg0: number) => any
->(a) => a + 1 : (a: number) => number
+>(a) => a + 1 : (a: number) => any
 >a : number
 >a + 1 : number
 >a : number

tests/baselines/reference/checkJsdocTypeTag2.errors.txt

@@ -3,8 +3,7 @@ tests/cases/conformance/jsdoc/0.js(6,5): error TS2322: Type '"hello"' is not ass
 tests/cases/conformance/jsdoc/0.js(10,4): error TS2345: Argument of type '"string"' is not assignable to parameter of type 'number'.
 tests/cases/conformance/jsdoc/0.js(17,1): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/jsdoc/0.js(20,21): error TS2339: Property 'concat' does not exist on type 'number'.
-tests/cases/conformance/jsdoc/0.js(24,7): error TS2322: Type '(a: number) => number' is not assignable to type '(arg0: number) => string'.
-  Type 'number' is not assignable to type 'string'.
+tests/cases/conformance/jsdoc/0.js(24,19): error TS2322: Type 'number' is not assignable to type 'string'.
 
 
 ==== tests/cases/conformance/jsdoc/0.js (6 errors) ====
@@ -42,7 +41,6 @@ tests/cases/conformance/jsdoc/0.js(24,7): error TS2322: Type '(a: number) => num
     
     /** @type {function (number): string} */
     const x4 = (a) => a + 1;
-          ~~
-!!! error TS2322: Type '(a: number) => number' is not assignable to type '(arg0: number) => string'.
-!!! error TS2322:   Type 'number' is not assignable to type 'string'.
+                      ~~~~~
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
     x4(0);

tests/baselines/reference/checkJsdocTypeTag2.types

@@ -13,7 +13,7 @@ var n = "hello";
 /** @type {function (number)} */
 const x1 = (a) => a + 1;
 >x1 : (arg0: number) => any
->(a) => a + 1 : (a: number) => number
+>(a) => a + 1 : (a: number) => any
 >a : number
 >a + 1 : number
 >a : number
@@ -47,7 +47,7 @@ a = x2(0);
 /** @type {function (number): number} */
 const x3 = (a) => a.concat("hi");
 >x3 : (arg0: number) => number
->(a) => a.concat("hi") : (a: number) => any
+>(a) => a.concat("hi") : (a: number) => number
 >a : number
 >a.concat("hi") : any
 >a.concat : any
@@ -63,7 +63,7 @@ x3(0);
 /** @type {function (number): string} */
 const x4 = (a) => a + 1;
 >x4 : (arg0: number) => string
->(a) => a + 1 : (a: number) => number
+>(a) => a + 1 : (a: number) => string
 >a : number
 >a + 1 : number
 >a : number

tests/baselines/reference/checkJsdocTypeTag5.errors.txt

@@ -4,9 +4,11 @@ tests/cases/conformance/jsdoc/test.js(7,24): error TS2322: Type 'number' is not
 tests/cases/conformance/jsdoc/test.js(10,17): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/jsdoc/test.js(12,14): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/jsdoc/test.js(14,24): error TS2322: Type 'number' is not assignable to type 'string'.
+tests/cases/conformance/jsdoc/test.js(34,5): error TS2322: Type '1 | 2' is not assignable to type '2 | 3'.
+  Type '1' is not assignable to type '2 | 3'.
 
 
-==== tests/cases/conformance/jsdoc/test.js (6 errors) ====
+==== tests/cases/conformance/jsdoc/test.js (7 errors) ====
     // all 6 should error on return statement/expression
     /** @type {(x: number) => string} */
     function h(x) { return x }
@@ -33,4 +35,27 @@ tests/cases/conformance/jsdoc/test.js(14,24): error TS2322: Type 'number' is not
     var k = function (x) { return x }
                            ~~~~~~~~
 !!! error TS2322: Type 'number' is not assignable to type 'string'.
+    
+    
+    /** @typedef {(x: 'hi' | 'bye') => 0 | 1 | 2} Argle */
+    /** @type {Argle} */
+    function blargle(s) {
+        return 0;
+    }
+    
+    /** @type {0 | 1 | 2} - assignment should not error */
+    var zeroonetwo = blargle('hi')
+    
+    /** @typedef {{(s: string): 0 | 1; (b: boolean): 2 | 3 }} Gioconda */
+    
+    /** @type {Gioconda} */
+    function monaLisa(sb) {
+        return typeof sb === 'string' ? 1 : 2;
+    }
+    
+    /** @type {2 | 3} - overloads are not supported, so there will be an error */
+    var twothree = monaLisa(false);
+        ~~~~~~~~
+!!! error TS2322: Type '1 | 2' is not assignable to type '2 | 3'.
+!!! error TS2322:   Type '1' is not assignable to type '2 | 3'.
     

tests/baselines/reference/checkJsdocTypeTag5.symbols

@@ -36,3 +36,34 @@ var k = function (x) { return x }
 >x : Symbol(x, Decl(test.js, 13, 18))
 >x : Symbol(x, Decl(test.js, 13, 18))
 
+
+/** @typedef {(x: 'hi' | 'bye') => 0 | 1 | 2} Argle */
+/** @type {Argle} */
+function blargle(s) {
+>blargle : Symbol(blargle, Decl(test.js, 13, 33))
+>s : Symbol(s, Decl(test.js, 18, 17))
+
+    return 0;
+}
+
+/** @type {0 | 1 | 2} - assignment should not error */
+var zeroonetwo = blargle('hi')
+>zeroonetwo : Symbol(zeroonetwo, Decl(test.js, 23, 3))
+>blargle : Symbol(blargle, Decl(test.js, 13, 33))
+
+/** @typedef {{(s: string): 0 | 1; (b: boolean): 2 | 3 }} Gioconda */
+
+/** @type {Gioconda} */
+function monaLisa(sb) {
+>monaLisa : Symbol(monaLisa, Decl(test.js, 23, 30))
+>sb : Symbol(sb, Decl(test.js, 28, 18))
+
+    return typeof sb === 'string' ? 1 : 2;
+>sb : Symbol(sb, Decl(test.js, 28, 18))
+}
+
+/** @type {2 | 3} - overloads are not supported, so there will be an error */
+var twothree = monaLisa(false);
+>twothree : Symbol(twothree, Decl(test.js, 33, 3))
+>monaLisa : Symbol(monaLisa, Decl(test.js, 23, 30))
+

tests/baselines/reference/checkJsdocTypeTag5.types

@@ -40,3 +40,45 @@ var k = function (x) { return x }
 >x : number
 >x : number
 
+
+/** @typedef {(x: 'hi' | 'bye') => 0 | 1 | 2} Argle */
+/** @type {Argle} */
+function blargle(s) {
+>blargle : (s: "hi" | "bye") => 0 | 1 | 2
+>s : "hi" | "bye"
+
+    return 0;
+>0 : 0
+}
+
+/** @type {0 | 1 | 2} - assignment should not error */
+var zeroonetwo = blargle('hi')
+>zeroonetwo : 0 | 1 | 2
+>blargle('hi') : 0 | 1 | 2
+>blargle : (s: "hi" | "bye") => 0 | 1 | 2
+>'hi' : "hi"
+
+/** @typedef {{(s: string): 0 | 1; (b: boolean): 2 | 3 }} Gioconda */
+
+/** @type {Gioconda} */
+function monaLisa(sb) {
+>monaLisa : (sb: any) => 1 | 2
+>sb : any
+
+    return typeof sb === 'string' ? 1 : 2;
+>typeof sb === 'string' ? 1 : 2 : 1 | 2
+>typeof sb === 'string' : boolean
+>typeof sb : "string" | "number" | "boolean" | "symbol" | "undefined" | "object" | "function"
+>sb : any
+>'string' : "string"
+>1 : 1
+>2 : 2
+}
+
+/** @type {2 | 3} - overloads are not supported, so there will be an error */
+var twothree = monaLisa(false);
+>twothree : 2 | 3
+>monaLisa(false) : 1 | 2
+>monaLisa : (sb: any) => 1 | 2
+>false : false
+

tests/baselines/reference/checkJsdocTypeTag6.errors.txt

@@ -0,0 +1,20 @@
+tests/cases/conformance/jsdoc/test.js(1,5): error TS8030: The type of a function declaration must be callable.
+tests/cases/conformance/jsdoc/test.js(7,5): error TS2322: Type '(prop: any) => void' is not assignable to type '{ prop: string; }'.
+  Property 'prop' is missing in type '(prop: any) => void'.
+
+
+==== tests/cases/conformance/jsdoc/test.js (2 errors) ====
+    /** @type {number} */
+        ~~~~~~~~~~~~~~
+!!! error TS8030: The type of a function declaration must be callable.
+    function f() {
+        return 1
+    }
+    
+    /** @type {{ prop: string }} */
+    var g = function (prop) {
+        ~
+!!! error TS2322: Type '(prop: any) => void' is not assignable to type '{ prop: string; }'.
+!!! error TS2322:   Property 'prop' is missing in type '(prop: any) => void'.
+    }
+    

tests/baselines/reference/checkJsdocTypeTag6.symbols

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/jsdoc/test.js ===
+/** @type {number} */
+function f() {
+>f : Symbol(f, Decl(test.js, 0, 0))
+
+    return 1
+}
+
+/** @type {{ prop: string }} */
+var g = function (prop) {
+>g : Symbol(g, Decl(test.js, 6, 3))
+>prop : Symbol(prop, Decl(test.js, 6, 18))
+}
+

tests/baselines/reference/checkJsdocTypeTag6.types

@@ -0,0 +1,16 @@
+=== tests/cases/conformance/jsdoc/test.js ===
+/** @type {number} */
+function f() {
+>f : () => number
+
+    return 1
+>1 : 1
+}
+
+/** @type {{ prop: string }} */
+var g = function (prop) {
+>g : { prop: string; }
+>function (prop) {} : (prop: any) => void
+>prop : any
+}
+

tests/baselines/reference/checkJsdocTypeTagOnObjectProperty2.errors.txt

@@ -1,8 +1,6 @@
 tests/cases/conformance/jsdoc/0.js(5,3): error TS2322: Type 'number' is not assignable to type 'string | undefined'.
-tests/cases/conformance/jsdoc/0.js(7,3): error TS2322: Type '(n1: number) => string' is not assignable to type '(arg0: number) => number'.
-  Type 'string' is not assignable to type 'number'.
-tests/cases/conformance/jsdoc/0.js(11,3): error TS2322: Type '(n1: number) => string' is not assignable to type '(arg0: number) => number'.
-  Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/jsdoc/0.js(8,7): error TS2322: Type '"42"' is not assignable to type 'number'.
+tests/cases/conformance/jsdoc/0.js(11,20): error TS2322: Type '"lol"' is not assignable to type 'number'.
 tests/cases/conformance/jsdoc/0.js(13,15): error TS2322: Type '"0"' is not assignable to type 'number'.
 tests/cases/conformance/jsdoc/0.js(15,3): error TS2322: Type 'undefined' is not assignable to type 'string'.
 tests/cases/conformance/jsdoc/0.js(19,5): error TS2322: Type 'number' is not assignable to type 'string'.
@@ -19,16 +17,14 @@ tests/cases/conformance/jsdoc/0.js(22,22): error TS2345: Argument of type '"0"'
 !!! error TS2322: Type 'number' is not assignable to type 'string | undefined'.
       /** @type {function(number): number} */
       method1(n1) {
-      ~~~~~~~
-!!! error TS2322: Type '(n1: number) => string' is not assignable to type '(arg0: number) => number'.
-!!! error TS2322:   Type 'string' is not assignable to type 'number'.
           return "42";
+          ~~~~~~~~~~~~
+!!! error TS2322: Type '"42"' is not assignable to type 'number'.
       },
       /** @type {function(number): number} */
       method2: (n1) => "lol",
-      ~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2322: Type '(n1: number) => string' is not assignable to type '(arg0: number) => number'.
-!!! error TS2322:   Type 'string' is not assignable to type 'number'.
+                       ~~~~~
+!!! error TS2322: Type '"lol"' is not assignable to type 'number'.
       /** @type {function(number): number} */
       arrowFunc: (num="0") => num + 42,
                   ~~~~~~~

tests/baselines/reference/checkJsdocTypeTagOnObjectProperty2.types

@@ -14,7 +14,7 @@ const obj = {
 
   /** @type {function(number): number} */
   method1(n1) {
->method1 : (n1: number) => string
+>method1 : (n1: number) => number
 >n1 : number
 
       return "42";
@@ -24,7 +24,7 @@ const obj = {
   /** @type {function(number): number} */
   method2: (n1) => "lol",
 >method2 : (arg0: number) => number
->(n1) => "lol" : (n1: number) => string
+>(n1) => "lol" : (n1: number) => number
 >n1 : number
 >"lol" : "lol"
 

tests/baselines/reference/conditionalTypesExcessProperties.errors.txt

@@ -0,0 +1,24 @@
+tests/cases/conformance/types/conditional/conditionalTypesExcessProperties.ts(8,5): error TS2322: Type '{ test: string; arg: A; }' is not assignable to type 'Something<A>'.
+  Type '{ test: string; arg: A; }' is not assignable to type 'A extends object ? { arg: A; } : { arg?: undefined; }'.
+tests/cases/conformance/types/conditional/conditionalTypesExcessProperties.ts(9,33): error TS2322: Type 'A' is not assignable to type 'Something<A>["arr"]'.
+  Type 'object' is not assignable to type 'Something<A>["arr"]'.
+
+
+==== tests/cases/conformance/types/conditional/conditionalTypesExcessProperties.ts (2 errors) ====
+    type Something<T> = { test: string } &  (T extends object ? {
+        arg: T
+    } : {
+        arg?: undefined
+        });
+    
+    function testFunc2<A extends object>(a: A, sa: Something<A>) {
+        sa = { test: 'hi', arg: a }; // not excess (but currently still not assignable)
+        ~~
+!!! error TS2322: Type '{ test: string; arg: A; }' is not assignable to type 'Something<A>'.
+!!! error TS2322:   Type '{ test: string; arg: A; }' is not assignable to type 'A extends object ? { arg: A; } : { arg?: undefined; }'.
+        sa = { test: 'bye', arg: a, arr: a } // excess
+                                    ~~~
+!!! error TS2322: Type 'A' is not assignable to type 'Something<A>["arr"]'.
+!!! error TS2322:   Type 'object' is not assignable to type 'Something<A>["arr"]'.
+    }
+    

tests/baselines/reference/conditionalTypesExcessProperties.js

@@ -0,0 +1,18 @@
+//// [conditionalTypesExcessProperties.ts]
+type Something<T> = { test: string } &  (T extends object ? {
+    arg: T
+} : {
+    arg?: undefined
+    });
+
+function testFunc2<A extends object>(a: A, sa: Something<A>) {
+    sa = { test: 'hi', arg: a }; // not excess (but currently still not assignable)
+    sa = { test: 'bye', arg: a, arr: a } // excess
+}
+
+
+//// [conditionalTypesExcessProperties.js]
+function testFunc2(a, sa) {
+    sa = { test: 'hi', arg: a }; // not excess (but currently still not assignable)
+    sa = { test: 'bye', arg: a, arr: a }; // excess
+}

tests/baselines/reference/conditionalTypesExcessProperties.symbols

@@ -0,0 +1,41 @@
+=== tests/cases/conformance/types/conditional/conditionalTypesExcessProperties.ts ===
+type Something<T> = { test: string } &  (T extends object ? {
+>Something : Symbol(Something, Decl(conditionalTypesExcessProperties.ts, 0, 0))
+>T : Symbol(T, Decl(conditionalTypesExcessProperties.ts, 0, 15))
+>test : Symbol(test, Decl(conditionalTypesExcessProperties.ts, 0, 21))
+>T : Symbol(T, Decl(conditionalTypesExcessProperties.ts, 0, 15))
+
+    arg: T
+>arg : Symbol(arg, Decl(conditionalTypesExcessProperties.ts, 0, 61))
+>T : Symbol(T, Decl(conditionalTypesExcessProperties.ts, 0, 15))
+
+} : {
+    arg?: undefined
+>arg : Symbol(arg, Decl(conditionalTypesExcessProperties.ts, 2, 5))
+
+    });
+
+function testFunc2<A extends object>(a: A, sa: Something<A>) {
+>testFunc2 : Symbol(testFunc2, Decl(conditionalTypesExcessProperties.ts, 4, 7))
+>A : Symbol(A, Decl(conditionalTypesExcessProperties.ts, 6, 19))
+>a : Symbol(a, Decl(conditionalTypesExcessProperties.ts, 6, 37))
+>A : Symbol(A, Decl(conditionalTypesExcessProperties.ts, 6, 19))
+>sa : Symbol(sa, Decl(conditionalTypesExcessProperties.ts, 6, 42))
+>Something : Symbol(Something, Decl(conditionalTypesExcessProperties.ts, 0, 0))
+>A : Symbol(A, Decl(conditionalTypesExcessProperties.ts, 6, 19))
+
+    sa = { test: 'hi', arg: a }; // not excess (but currently still not assignable)
+>sa : Symbol(sa, Decl(conditionalTypesExcessProperties.ts, 6, 42))
+>test : Symbol(test, Decl(conditionalTypesExcessProperties.ts, 7, 10))
+>arg : Symbol(arg, Decl(conditionalTypesExcessProperties.ts, 7, 22))
+>a : Symbol(a, Decl(conditionalTypesExcessProperties.ts, 6, 37))
+
+    sa = { test: 'bye', arg: a, arr: a } // excess
+>sa : Symbol(sa, Decl(conditionalTypesExcessProperties.ts, 6, 42))
+>test : Symbol(test, Decl(conditionalTypesExcessProperties.ts, 8, 10))
+>arg : Symbol(arg, Decl(conditionalTypesExcessProperties.ts, 8, 23))
+>a : Symbol(a, Decl(conditionalTypesExcessProperties.ts, 6, 37))
+>arr : Symbol(arr, Decl(conditionalTypesExcessProperties.ts, 8, 31))
+>a : Symbol(a, Decl(conditionalTypesExcessProperties.ts, 6, 37))
+}
+

tests/baselines/reference/conditionalTypesExcessProperties.types

@@ -0,0 +1,47 @@
+=== tests/cases/conformance/types/conditional/conditionalTypesExcessProperties.ts ===
+type Something<T> = { test: string } &  (T extends object ? {
+>Something : Something<T>
+>T : T
+>test : string
+>T : T
+
+    arg: T
+>arg : T
+>T : T
+
+} : {
+    arg?: undefined
+>arg : undefined
+
+    });
+
+function testFunc2<A extends object>(a: A, sa: Something<A>) {
+>testFunc2 : <A extends object>(a: A, sa: Something<A>) => void
+>A : A
+>a : A
+>A : A
+>sa : Something<A>
+>Something : Something<T>
+>A : A
+
+    sa = { test: 'hi', arg: a }; // not excess (but currently still not assignable)
+>sa = { test: 'hi', arg: a } : { test: string; arg: A; }
+>sa : Something<A>
+>{ test: 'hi', arg: a } : { test: string; arg: A; }
+>test : string
+>'hi' : "hi"
+>arg : A
+>a : A
+
+    sa = { test: 'bye', arg: a, arr: a } // excess
+>sa = { test: 'bye', arg: a, arr: a } : { test: string; arg: A; arr: A; }
+>sa : Something<A>
+>{ test: 'bye', arg: a, arr: a } : { test: string; arg: A; arr: A; }
+>test : string
+>'bye' : "bye"
+>arg : A
+>a : A
+>arr : A
+>a : A
+}
+

tests/baselines/reference/destructuringTempOccursAfterPrologue.js

@@ -1,12 +1,14 @@
 //// [destructuringTempOccursAfterPrologue.ts]
 function test(p: any) {
     'use strict';
+    'use strong';
     p = { prop: p } = p;
 }
 
 //// [destructuringTempOccursAfterPrologue.js]
 function test(p) {
     'use strict';
+    'use strong';
     var _a;
     p = (_a = p, p = _a.prop, _a);
 }

tests/baselines/reference/destructuringTempOccursAfterPrologue.symbols

@@ -4,9 +4,10 @@ function test(p: any) {
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
 
     'use strict';
+    'use strong';
     p = { prop: p } = p;
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
->prop : Symbol(prop, Decl(destructuringTempOccursAfterPrologue.ts, 2, 9))
+>prop : Symbol(prop, Decl(destructuringTempOccursAfterPrologue.ts, 3, 9))
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
 }

tests/baselines/reference/destructuringTempOccursAfterPrologue.types

@@ -6,6 +6,9 @@ function test(p: any) {
     'use strict';
 >'use strict' : "use strict"
 
+    'use strong';
+>'use strong' : "use strong"
+
     p = { prop: p } = p;
 >p = { prop: p } = p : any
 >p : any

tests/baselines/reference/functionParameterArityMismatch.errors.txt

@@ -0,0 +1,39 @@
+tests/cases/compiler/functionParameterArityMismatch.ts(3,1): error TS2554: Expected 1-3 arguments, but got 0.
+tests/cases/compiler/functionParameterArityMismatch.ts(4,1): error TS2575: No overload expects 2 arguments, but overloads do exist that expect either 1 or 3 arguments.
+tests/cases/compiler/functionParameterArityMismatch.ts(5,1): error TS2554: Expected 1-3 arguments, but got 4.
+tests/cases/compiler/functionParameterArityMismatch.ts(11,1): error TS2575: No overload expects 1 arguments, but overloads do exist that expect either 0 or 2 arguments.
+tests/cases/compiler/functionParameterArityMismatch.ts(12,1): error TS2575: No overload expects 3 arguments, but overloads do exist that expect either 2 or 4 arguments.
+tests/cases/compiler/functionParameterArityMismatch.ts(13,1): error TS2575: No overload expects 5 arguments, but overloads do exist that expect either 4 or 6 arguments.
+tests/cases/compiler/functionParameterArityMismatch.ts(14,1): error TS2554: Expected 0-6 arguments, but got 7.
+
+
+==== tests/cases/compiler/functionParameterArityMismatch.ts (7 errors) ====
+    declare function f1(a: number);
+    declare function f1(a: number, b: number, c: number);
+    f1();
+    ~~~~
+!!! error TS2554: Expected 1-3 arguments, but got 0.
+    f1(1, 2);
+    ~~~~~~~~
+!!! error TS2575: No overload expects 2 arguments, but overloads do exist that expect either 1 or 3 arguments.
+    f1(1, 2, 3, 4);
+    ~~~~~~~~~~~~~~
+!!! error TS2554: Expected 1-3 arguments, but got 4.
+    
+    declare function f2();
+    declare function f2(a: number, b: number);
+    declare function f2(a: number, b: number, c: number, d: number);
+    declare function f2(a: number, b: number, c: number, d: number, e: number, f: number);
+    f2(1);
+    ~~~~~
+!!! error TS2575: No overload expects 1 arguments, but overloads do exist that expect either 0 or 2 arguments.
+    f2(1, 2, 3);
+    ~~~~~~~~~~~
+!!! error TS2575: No overload expects 3 arguments, but overloads do exist that expect either 2 or 4 arguments.
+    f2(1, 2, 3, 4, 5);
+    ~~~~~~~~~~~~~~~~~
+!!! error TS2575: No overload expects 5 arguments, but overloads do exist that expect either 4 or 6 arguments.
+    f2(1, 2, 3, 4, 5, 6, 7);
+    ~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2554: Expected 0-6 arguments, but got 7.
+    

tests/baselines/reference/functionParameterArityMismatch.js

@@ -0,0 +1,25 @@
+//// [functionParameterArityMismatch.ts]
+declare function f1(a: number);
+declare function f1(a: number, b: number, c: number);
+f1();
+f1(1, 2);
+f1(1, 2, 3, 4);
+
+declare function f2();
+declare function f2(a: number, b: number);
+declare function f2(a: number, b: number, c: number, d: number);
+declare function f2(a: number, b: number, c: number, d: number, e: number, f: number);
+f2(1);
+f2(1, 2, 3);
+f2(1, 2, 3, 4, 5);
+f2(1, 2, 3, 4, 5, 6, 7);
+
+
+//// [functionParameterArityMismatch.js]
+f1();
+f1(1, 2);
+f1(1, 2, 3, 4);
+f2(1);
+f2(1, 2, 3);
+f2(1, 2, 3, 4, 5);
+f2(1, 2, 3, 4, 5, 6, 7);

tests/baselines/reference/functionParameterArityMismatch.symbols

@@ -0,0 +1,56 @@
+=== tests/cases/compiler/functionParameterArityMismatch.ts ===
+declare function f1(a: number);
+>f1 : Symbol(f1, Decl(functionParameterArityMismatch.ts, 0, 0), Decl(functionParameterArityMismatch.ts, 0, 31))
+>a : Symbol(a, Decl(functionParameterArityMismatch.ts, 0, 20))
+
+declare function f1(a: number, b: number, c: number);
+>f1 : Symbol(f1, Decl(functionParameterArityMismatch.ts, 0, 0), Decl(functionParameterArityMismatch.ts, 0, 31))
+>a : Symbol(a, Decl(functionParameterArityMismatch.ts, 1, 20))
+>b : Symbol(b, Decl(functionParameterArityMismatch.ts, 1, 30))
+>c : Symbol(c, Decl(functionParameterArityMismatch.ts, 1, 41))
+
+f1();
+>f1 : Symbol(f1, Decl(functionParameterArityMismatch.ts, 0, 0), Decl(functionParameterArityMismatch.ts, 0, 31))
+
+f1(1, 2);
+>f1 : Symbol(f1, Decl(functionParameterArityMismatch.ts, 0, 0), Decl(functionParameterArityMismatch.ts, 0, 31))
+
+f1(1, 2, 3, 4);
+>f1 : Symbol(f1, Decl(functionParameterArityMismatch.ts, 0, 0), Decl(functionParameterArityMismatch.ts, 0, 31))
+
+declare function f2();
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+
+declare function f2(a: number, b: number);
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+>a : Symbol(a, Decl(functionParameterArityMismatch.ts, 7, 20))
+>b : Symbol(b, Decl(functionParameterArityMismatch.ts, 7, 30))
+
+declare function f2(a: number, b: number, c: number, d: number);
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+>a : Symbol(a, Decl(functionParameterArityMismatch.ts, 8, 20))
+>b : Symbol(b, Decl(functionParameterArityMismatch.ts, 8, 30))
+>c : Symbol(c, Decl(functionParameterArityMismatch.ts, 8, 41))
+>d : Symbol(d, Decl(functionParameterArityMismatch.ts, 8, 52))
+
+declare function f2(a: number, b: number, c: number, d: number, e: number, f: number);
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+>a : Symbol(a, Decl(functionParameterArityMismatch.ts, 9, 20))
+>b : Symbol(b, Decl(functionParameterArityMismatch.ts, 9, 30))
+>c : Symbol(c, Decl(functionParameterArityMismatch.ts, 9, 41))
+>d : Symbol(d, Decl(functionParameterArityMismatch.ts, 9, 52))
+>e : Symbol(e, Decl(functionParameterArityMismatch.ts, 9, 63))
+>f : Symbol(f, Decl(functionParameterArityMismatch.ts, 9, 74))
+
+f2(1);
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+
+f2(1, 2, 3);
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+
+f2(1, 2, 3, 4, 5);
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+
+f2(1, 2, 3, 4, 5, 6, 7);
+>f2 : Symbol(f2, Decl(functionParameterArityMismatch.ts, 4, 15), Decl(functionParameterArityMismatch.ts, 6, 22), Decl(functionParameterArityMismatch.ts, 7, 42), Decl(functionParameterArityMismatch.ts, 8, 64))
+

tests/baselines/reference/functionParameterArityMismatch.types

@@ -0,0 +1,85 @@
+=== tests/cases/compiler/functionParameterArityMismatch.ts ===
+declare function f1(a: number);
+>f1 : { (a: number): any; (a: number, b: number, c: number): any; }
+>a : number
+
+declare function f1(a: number, b: number, c: number);
+>f1 : { (a: number): any; (a: number, b: number, c: number): any; }
+>a : number
+>b : number
+>c : number
+
+f1();
+>f1() : any
+>f1 : { (a: number): any; (a: number, b: number, c: number): any; }
+
+f1(1, 2);
+>f1(1, 2) : any
+>f1 : { (a: number): any; (a: number, b: number, c: number): any; }
+>1 : 1
+>2 : 2
+
+f1(1, 2, 3, 4);
+>f1(1, 2, 3, 4) : any
+>f1 : { (a: number): any; (a: number, b: number, c: number): any; }
+>1 : 1
+>2 : 2
+>3 : 3
+>4 : 4
+
+declare function f2();
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+
+declare function f2(a: number, b: number);
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+>a : number
+>b : number
+
+declare function f2(a: number, b: number, c: number, d: number);
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+>a : number
+>b : number
+>c : number
+>d : number
+
+declare function f2(a: number, b: number, c: number, d: number, e: number, f: number);
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+>a : number
+>b : number
+>c : number
+>d : number
+>e : number
+>f : number
+
+f2(1);
+>f2(1) : any
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+>1 : 1
+
+f2(1, 2, 3);
+>f2(1, 2, 3) : any
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+>1 : 1
+>2 : 2
+>3 : 3
+
+f2(1, 2, 3, 4, 5);
+>f2(1, 2, 3, 4, 5) : any
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+>1 : 1
+>2 : 2
+>3 : 3
+>4 : 4
+>5 : 5
+
+f2(1, 2, 3, 4, 5, 6, 7);
+>f2(1, 2, 3, 4, 5, 6, 7) : any
+>f2 : { (): any; (a: number, b: number): any; (a: number, b: number, c: number, d: number): any; (a: number, b: number, c: number, d: number, e: number, f: number): any; }
+>1 : 1
+>2 : 2
+>3 : 3
+>4 : 4
+>5 : 5
+>6 : 6
+>7 : 7
+

tests/baselines/reference/importTypeAmbientMissing.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/conformance/types/import/importTypeAmbientMissing.ts(8,10): error TS2307: Cannot find module 'fo'.
+tests/cases/conformance/types/import/importTypeAmbientMissing.ts(8,17): error TS2307: Cannot find module 'fo'.
 
 
 ==== tests/cases/conformance/types/import/importTypeAmbientMissing.ts (1 errors) ====
@@ -10,7 +10,7 @@ tests/cases/conformance/types/import/importTypeAmbientMissing.ts(8,10): error TS
         export = Point;
     }
     const x: import("fo") = { x: 0, y: 0 }; // typo, error
-             ~~~~~~~~~~~~
+                    ~~~~
 !!! error TS2307: Cannot find module 'fo'.
     
     

tests/baselines/reference/importTypeLocalMissing.errors.txt

@@ -1,7 +1,7 @@
-tests/cases/conformance/types/import/usage.ts(1,17): error TS2307: Cannot find module './fo'.
-tests/cases/conformance/types/import/usage.ts(2,15): error TS2307: Cannot find module './fo2'.
+tests/cases/conformance/types/import/usage.ts(1,24): error TS2307: Cannot find module './fo'.
+tests/cases/conformance/types/import/usage.ts(2,22): error TS2307: Cannot find module './fo2'.
 tests/cases/conformance/types/import/usage.ts(3,36): error TS2694: Namespace '"tests/cases/conformance/types/import/foo2".Bar' has no exported member 'Q'.
-tests/cases/conformance/types/import/usage.ts(10,18): error TS2307: Cannot find module './fo2'.
+tests/cases/conformance/types/import/usage.ts(10,32): error TS2307: Cannot find module './fo2'.
 
 
 ==== tests/cases/conformance/types/import/foo.ts (0 errors) ====
@@ -34,10 +34,10 @@ tests/cases/conformance/types/import/usage.ts(10,18): error TS2307: Cannot find
     
 ==== tests/cases/conformance/types/import/usage.ts (4 errors) ====
     export const x: import("./fo") = { x: 0, y: 0 };
-                    ~~~~~~~~~~~~~~
+                           ~~~~~~
 !!! error TS2307: Cannot find module './fo'.
     export let y: import("./fo2").Bar.I = { a: "", b: 0 };
-                  ~~~~~~~~~~~~~~~~~~~~~
+                         ~~~~~~~
 !!! error TS2307: Cannot find module './fo2'.
     export let z: import("./foo2").Bar.Q = { a: "", b: 0 };
                                        ~
@@ -49,7 +49,7 @@ tests/cases/conformance/types/import/usage.ts(10,18): error TS2307: Cannot find
     }
     
     export let shim: typeof import("./fo2") = {
-                     ~~~~~~~~~~~~~~~~~~~~~~
+                                   ~~~~~~~
 !!! error TS2307: Cannot find module './fo2'.
         Bar: Bar2
     };

tests/baselines/reference/metadataImportType.errors.txt

@@ -1,5 +1,5 @@
 tests/cases/compiler/metadataImportType.ts(2,6): error TS2304: Cannot find name 'test'.
-tests/cases/compiler/metadataImportType.ts(3,8): error TS2307: Cannot find module './b'.
+tests/cases/compiler/metadataImportType.ts(3,15): error TS2307: Cannot find module './b'.
 
 
 ==== tests/cases/compiler/metadataImportType.ts (2 errors) ====
@@ -8,6 +8,6 @@ tests/cases/compiler/metadataImportType.ts(3,8): error TS2307: Cannot find modul
          ~~~~
 !!! error TS2304: Cannot find name 'test'.
         b: import('./b').B
-           ~~~~~~~~~~~~~~~
+                  ~~~~~
 !!! error TS2307: Cannot find module './b'.
     }

tests/baselines/reference/moduleExportWithExportPropertyAssignment4.errors.txt

@@ -2,6 +2,10 @@ tests/cases/conformance/salsa/a.js(4,17): error TS2339: Property 'toFixed' does
   Property 'toFixed' does not exist on type 'string'.
 tests/cases/conformance/salsa/a.js(5,16): error TS2339: Property 'toFixed' does not exist on type 'string | number'.
   Property 'toFixed' does not exist on type 'string'.
+tests/cases/conformance/salsa/mod1.js(2,1): error TS2323: Cannot redeclare exported variable 'bothBefore'.
+tests/cases/conformance/salsa/mod1.js(4,1): error TS2323: Cannot redeclare exported variable 'bothBefore'.
+tests/cases/conformance/salsa/mod1.js(5,1): error TS2323: Cannot redeclare exported variable 'bothAfter'.
+tests/cases/conformance/salsa/mod1.js(10,1): error TS2323: Cannot redeclare exported variable 'bothAfter'.
 
 
 ==== tests/cases/conformance/salsa/a.js (2 errors) ====
@@ -21,16 +25,24 @@ tests/cases/conformance/salsa/a.js(5,16): error TS2339: Property 'toFixed' does
 ==== tests/cases/conformance/salsa/requires.d.ts (0 errors) ====
     declare var module: { exports: any };
     declare function require(name: string): any;
-==== tests/cases/conformance/salsa/mod1.js (0 errors) ====
+==== tests/cases/conformance/salsa/mod1.js (4 errors) ====
     /// <reference path='./requires.d.ts' />
     module.exports.bothBefore = 'string'
+    ~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2323: Cannot redeclare exported variable 'bothBefore'.
     A.justExport = 4
     A.bothBefore = 2
+    ~~~~~~~~~~~~
+!!! error TS2323: Cannot redeclare exported variable 'bothBefore'.
     A.bothAfter = 3
+    ~~~~~~~~~~~
+!!! error TS2323: Cannot redeclare exported variable 'bothAfter'.
     module.exports = A
     function A() {
         this.p = 1
     }
     module.exports.bothAfter = 'string'
+    ~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2323: Cannot redeclare exported variable 'bothAfter'.
     module.exports.justProperty = 'string'
     

tests/baselines/reference/symbolLinkDeclarationEmitModuleNames.js

@@ -81,7 +81,7 @@ export declare const CONTROLLER_CLASS: BindingKey<import("@loopback/context/src/
 tests/cases/compiler/monorepo/context/src/bindingkey.d.ts(1,29): error TS2307: Cannot find module '@loopback/context'.
 tests/cases/compiler/monorepo/core/src/application.d.ts(1,29): error TS2307: Cannot find module '@loopback/context'.
 tests/cases/compiler/monorepo/core/src/usage.d.ts(1,28): error TS2307: Cannot find module '@loopback/context'.
-tests/cases/compiler/monorepo/core/src/usage.d.ts(2,51): error TS2307: Cannot find module '@loopback/context/src/value-promise'.
+tests/cases/compiler/monorepo/core/src/usage.d.ts(2,58): error TS2307: Cannot find module '@loopback/context/src/value-promise'.
 
 
 ==== tests/cases/compiler/monorepo/core/src/application.d.ts (1 errors) ====
@@ -95,7 +95,7 @@ tests/cases/compiler/monorepo/core/src/usage.d.ts(2,51): error TS2307: Cannot fi
                                ~~~~~~~~~~~~~~~~~~~
 !!! error TS2307: Cannot find module '@loopback/context'.
     export declare const CONTROLLER_CLASS: BindingKey<import("@loopback/context/src/value-promise").Constructor<any>>;
-                                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+                                                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2307: Cannot find module '@loopback/context/src/value-promise'.
     
 ==== /.src/tests/cases/compiler/monorepo/context/src/value-promise.d.ts (0 errors) ====

tests/baselines/reference/symbolLinkDeclarationEmitModuleNamesRootDir.js

@@ -47,7 +47,7 @@ export declare const CONTROLLER_CLASS: BindingKey<import("@loopback/context/src/
 
 tests/cases/compiler/monorepo/core/dist/src/application.d.ts(1,29): error TS2307: Cannot find module '@loopback/context'.
 tests/cases/compiler/monorepo/core/dist/src/usage.d.ts(1,28): error TS2307: Cannot find module '@loopback/context'.
-tests/cases/compiler/monorepo/core/dist/src/usage.d.ts(2,51): error TS2307: Cannot find module '@loopback/context/src/value-promise'.
+tests/cases/compiler/monorepo/core/dist/src/usage.d.ts(2,58): error TS2307: Cannot find module '@loopback/context/src/value-promise'.
 
 
 ==== tests/cases/compiler/monorepo/core/tsconfig.json (0 errors) ====
@@ -82,6 +82,6 @@ tests/cases/compiler/monorepo/core/dist/src/usage.d.ts(2,51): error TS2307: Cann
                                ~~~~~~~~~~~~~~~~~~~
 !!! error TS2307: Cannot find module '@loopback/context'.
     export declare const CONTROLLER_CLASS: BindingKey<import("@loopback/context/src/value-promise").Constructor<any>>;
-                                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+                                                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2307: Cannot find module '@loopback/context/src/value-promise'.
     

tests/baselines/reference/typedefTagTypeResolution.types

@@ -35,6 +35,6 @@ function g(vvvvv) {
 /** @type {Cb} */
 const cb = x => {}
 >cb : Cb
->x => {} : (x: any) => void
+>x => {} : (x: any) => any
 >x : any
 

tests/baselines/reference/umd-errors.types

@@ -1,7 +1,7 @@
 === tests/cases/conformance/externalModules/err1.d.ts ===
 // Illegal, can't be in script file
 export as namespace Foo;
->Foo : No type information available!
+>Foo : any
 
 === tests/cases/conformance/externalModules/err2.d.ts ===
 // Illegal, can't be in external ambient module
@@ -9,7 +9,7 @@ declare module "Foo" {
 >"Foo" : typeof import("Foo")
 
 	export as namespace Bar;
->Bar : No type information available!
+>Bar : any
 }
 
 === tests/cases/conformance/externalModules/err3.d.ts ===
@@ -35,7 +35,7 @@ export namespace B {
 >B : typeof B
 
 	export as namespace C1;
->C1 : No type information available!
+>C1 : any
 }
 
 === tests/cases/conformance/externalModules/err5.ts ===
@@ -44,6 +44,6 @@ export var v;
 >v : any
 
 export as namespace C2;
->C2 : No type information available!
+>C2 : any
 
 

tests/baselines/reference/user/async.log

@@ -125,8 +125,8 @@ node_modules/async/dist/async.js(2116,20): error TS2345: Argument of type 'Funct
   Type 'Function' is not assignable to type 'number'.
 node_modules/async/dist/async.js(2274,21): error TS2554: Expected 0 arguments, but got 2.
 node_modules/async/dist/async.js(2425,20): error TS1005: '}' expected.
-node_modules/async/dist/async.js(2450,5): error TS2322: Type '{ [x: string]: any; _tasks: DLL; concurrency: any; payload: any; saturated: () => void; unsaturat...' is not assignable to type 'NodeModule'.
-  Property 'exports' is missing in type '{ [x: string]: any; _tasks: DLL; concurrency: any; payload: any; saturated: () => void; unsaturat...'.
+node_modules/async/dist/async.js(2450,5): error TS2322: Type '{ [x: string]: any; _tasks: DLL; concurrency: any; payload: any; saturated: () => void; unsaturated: () => void; buffer: number; empty: () => void; drain: () => void; error: () => void; started: boolean; paused: boolean; ... 10 more ...; resume: () => void; }' is not assignable to type 'NodeModule'.
+  Property 'exports' is missing in type '{ [x: string]: any; _tasks: DLL; concurrency: any; payload: any; saturated: () => void; unsaturated: () => void; buffer: number; empty: () => void; drain: () => void; error: () => void; started: boolean; paused: boolean; ... 10 more ...; resume: () => void; }'.
 node_modules/async/dist/async.js(2521,9): error TS2722: Cannot invoke an object which is possibly 'undefined'.
 node_modules/async/dist/async.js(2564,31): error TS2345: Argument of type 'IArguments' is not assignable to parameter of type 'any[]'.
   Property 'push' is missing in type 'IArguments'.
@@ -160,7 +160,7 @@ node_modules/async/dist/async.js(3848,23): error TS1003: Identifier expected.
 node_modules/async/dist/async.js(3848,24): error TS1003: Identifier expected.
 node_modules/async/dist/async.js(3848,25): error TS1003: Identifier expected.
 node_modules/async/dist/async.js(4059,20): error TS1005: '}' expected.
-node_modules/async/dist/async.js(4095,5): error TS2322: Type '{ [x: string]: any; _tasks: DLL; concurrency: any; payload: any; saturated: () => void; unsaturat...' is not assignable to type 'NodeModule'.
+node_modules/async/dist/async.js(4095,5): error TS2322: Type '{ [x: string]: any; _tasks: DLL; concurrency: any; payload: any; saturated: () => void; unsaturated: () => void; buffer: number; empty: () => void; drain: () => void; error: () => void; started: boolean; paused: boolean; ... 10 more ...; resume: () => void; }' is not assignable to type 'NodeModule'.
 node_modules/async/dist/async.js(4117,20): error TS1005: '}' expected.
 node_modules/async/dist/async.js(4128,7): error TS2339: Property 'push' does not exist on type 'NodeModule'.
 node_modules/async/dist/async.js(4133,11): error TS2339: Property 'started' does not exist on type 'NodeModule'.

tests/baselines/reference/user/bluebird.log

@@ -24,9 +24,9 @@ node_modules/bluebird/js/release/debuggability.js(745,37): error TS2339: Propert
 node_modules/bluebird/js/release/debuggability.js(784,38): error TS2339: Property 'stack' does not exist on type 'CapturedTrace'.
 node_modules/bluebird/js/release/debuggability.js(793,25): error TS2554: Expected 0 arguments, but got 1.
 node_modules/bluebird/js/release/errors.js(10,49): error TS2350: Only a void function can be called with the 'new' keyword.
-node_modules/bluebird/js/release/errors.js(46,1): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ...' has no compatible call signatures.
-node_modules/bluebird/js/release/errors.js(92,18): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '{ <T>(a: T[]): ReadonlyArray<T>; <T extends Function>(f: T): T; <T>(o: T): Readonly<T>; } | ((obj...' has no compatible call signatures.
-node_modules/bluebird/js/release/errors.js(99,5): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ...' has no compatible call signatures.
+node_modules/bluebird/js/release/errors.js(46,1): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ((o: any, key: any, desc: any) => any)' has no compatible call signatures.
+node_modules/bluebird/js/release/errors.js(92,18): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '{ <T>(a: T[]): ReadonlyArray<T>; <T extends Function>(f: T): T; <T>(o: T): Readonly<T>; } | ((obj: any) => any)' has no compatible call signatures.
+node_modules/bluebird/js/release/errors.js(99,5): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ((o: any, key: any, desc: any) => any)' has no compatible call signatures.
 node_modules/bluebird/js/release/generators.js(159,21): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
 node_modules/bluebird/js/release/generators.js(190,15): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
 node_modules/bluebird/js/release/generators.js(208,15): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
@@ -52,7 +52,7 @@ node_modules/bluebird/js/release/promise.js(4,12): error TS2351: Cannot use 'new
 node_modules/bluebird/js/release/promise.js(7,24): error TS2339: Property 'PromiseInspection' does not exist on type 'typeof Promise'.
 node_modules/bluebird/js/release/promise.js(10,27): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
 node_modules/bluebird/js/release/promise.js(20,32): error TS2322: Type 'null' is not assignable to type 'Domain'.
-node_modules/bluebird/js/release/promise.js(33,1): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ...' has no compatible call signatures.
+node_modules/bluebird/js/release/promise.js(33,1): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ((o: any, key: any, desc: any) => any)' has no compatible call signatures.
 node_modules/bluebird/js/release/promise.js(62,15): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
 node_modules/bluebird/js/release/promise.js(65,15): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
 node_modules/bluebird/js/release/promise.js(123,14): error TS2339: Property '_warn' does not exist on type 'Promise'.
@@ -155,10 +155,10 @@ node_modules/bluebird/js/release/some.js(133,23): error TS2339: Property 'promis
 node_modules/bluebird/js/release/using.js(78,20): error TS2339: Property 'doDispose' does not exist on type 'Disposer'.
 node_modules/bluebird/js/release/using.js(97,23): error TS2339: Property 'data' does not exist on type 'FunctionDisposer'.
 node_modules/bluebird/js/release/using.js(223,15): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
-node_modules/bluebird/js/release/util.js(97,5): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ...' has no compatible call signatures.
+node_modules/bluebird/js/release/util.js(97,5): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ((o: any, key: any, desc: any) => any)' has no compatible call signatures.
 node_modules/bluebird/js/release/util.js(247,28): error TS2554: Expected 0 arguments, but got 2.
-node_modules/bluebird/js/release/util.js(275,17): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ...' has no compatible call signatures.
-node_modules/bluebird/js/release/util.js(275,45): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol) => PropertyDescriptor | undefined) | ((o: any, key: any) =...' has no compatible call signatures.
+node_modules/bluebird/js/release/util.js(275,17): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol, attributes: PropertyDescriptor & ThisType<any>) => any) | ((o: any, key: any, desc: any) => any)' has no compatible call signatures.
+node_modules/bluebird/js/release/util.js(275,45): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((o: any, p: string | number | symbol) => PropertyDescriptor | undefined) | ((o: any, key: any) => { [x: string]: any; value: any; })' has no compatible call signatures.
 node_modules/bluebird/js/release/util.js(363,25): error TS2304: Cannot find name 'chrome'.
 node_modules/bluebird/js/release/util.js(363,51): error TS2304: Cannot find name 'chrome'.
 node_modules/bluebird/js/release/util.js(364,25): error TS2304: Cannot find name 'chrome'.

tests/baselines/reference/user/debug.log

@@ -17,11 +17,11 @@ node_modules/debug/src/debug.js(46,13): error TS2407: The right-hand side of a '
 node_modules/debug/src/debug.js(47,57): error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 node_modules/debug/src/debug.js(51,18): error TS2339: Property 'colors' does not exist on type 'typeof import("/debug/node_modules/debug/src/debug")'.
 node_modules/debug/src/debug.js(51,50): error TS2339: Property 'colors' does not exist on type 'typeof import("/debug/node_modules/debug/src/debug")'.
-node_modules/debug/src/debug.js(75,10): error TS2339: Property 'diff' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; des...'.
-node_modules/debug/src/debug.js(76,10): error TS2339: Property 'prev' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; des...'.
-node_modules/debug/src/debug.js(77,10): error TS2339: Property 'curr' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; des...'.
+node_modules/debug/src/debug.js(75,10): error TS2339: Property 'diff' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; destroy: () => boolean; }'.
+node_modules/debug/src/debug.js(76,10): error TS2339: Property 'prev' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; destroy: () => boolean; }'.
+node_modules/debug/src/debug.js(77,10): error TS2339: Property 'curr' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; destroy: () => boolean; }'.
 node_modules/debug/src/debug.js(112,13): error TS2551: Property 'formatArgs' does not exist on type 'typeof import("/debug/node_modules/debug/src/debug")'. Did you mean 'formatters'?
-node_modules/debug/src/debug.js(114,23): error TS2339: Property 'log' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; des...'.
+node_modules/debug/src/debug.js(114,23): error TS2339: Property 'log' does not exist on type '{ (...args: any[]): void; namespace: string; enabled: boolean; useColors: any; color: number; destroy: () => boolean; }'.
 node_modules/debug/src/debug.js(114,38): error TS2339: Property 'log' does not exist on type 'typeof import("/debug/node_modules/debug/src/debug")'.
 node_modules/debug/src/debug.js(120,29): error TS2339: Property 'useColors' does not exist on type 'typeof import("/debug/node_modules/debug/src/debug")'.
 node_modules/debug/src/debug.js(125,37): error TS2339: Property 'init' does not exist on type 'typeof import("/debug/node_modules/debug/src/debug")'.

tests/baselines/reference/user/lodash.log

@@ -273,33 +273,33 @@ node_modules/lodash/fp/_baseConvert.js(144,5): error TS2559: Type 'Function' has
 node_modules/lodash/fp/_baseConvert.js(145,5): error TS2322: Type 'string' is not assignable to type 'Function'.
 node_modules/lodash/fp/_baseConvert.js(146,5): error TS2322: Type 'undefined' is not assignable to type 'string'.
 node_modules/lodash/fp/_baseConvert.js(165,31): error TS2339: Property 'runInContext' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(184,21): error TS2339: Property 'ary' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(184,21): error TS2339: Property 'ary' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'ary' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(185,24): error TS2339: Property 'assign' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(185,24): error TS2339: Property 'assign' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'assign' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(186,23): error TS2339: Property 'clone' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(186,23): error TS2339: Property 'clone' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'clone' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(187,23): error TS2339: Property 'curry' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(187,23): error TS2339: Property 'curry' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'curry' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(188,22): error TS2339: Property 'forEach' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(188,22): error TS2339: Property 'forEach' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'forEach' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(189,25): error TS2339: Property 'isArray' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(189,25): error TS2339: Property 'isArray' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'isArray' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(190,25): error TS2339: Property 'isError' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(190,25): error TS2339: Property 'isError' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'isError' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(191,28): error TS2339: Property 'isFunction' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(191,28): error TS2339: Property 'isFunction' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'isFunction' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(192,27): error TS2339: Property 'isWeakMap' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(192,27): error TS2339: Property 'isWeakMap' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'isWeakMap' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(193,22): error TS2339: Property 'keys' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(193,22): error TS2339: Property 'keys' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'keys' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(194,23): error TS2339: Property 'rearg' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(194,23): error TS2339: Property 'rearg' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'rearg' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(195,27): error TS2339: Property 'toInteger' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(195,27): error TS2339: Property 'toInteger' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'toInteger' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(196,24): error TS2339: Property 'toPath' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': ...'.
+node_modules/lodash/fp/_baseConvert.js(196,24): error TS2339: Property 'toPath' does not exist on type 'Function | { [x: string]: any; 'ary': any; 'assign': any; 'clone': any; 'curry': any; 'forEach': any; 'isArray': any; 'isError': any; 'isFunction': any; 'isWeakMap': any; 'iteratee': any; 'keys': any; 'rearg': any; 'toInteger': any; 'toPath': any; }'.
   Property 'toPath' does not exist on type 'Function'.
-node_modules/lodash/fp/_baseConvert.js(263,57): error TS2345: Argument of type '{ cap?: boolean; curry?: boolean; fixed?: boolean; immutable?: boolean; rearg?: boolean; } | unde...' is not assignable to parameter of type 'Function'.
+node_modules/lodash/fp/_baseConvert.js(263,57): error TS2345: Argument of type '{ cap?: boolean; curry?: boolean; fixed?: boolean; immutable?: boolean; rearg?: boolean; } | undefined' is not assignable to parameter of type 'Function'.
   Type 'undefined' is not assignable to type 'Function'.
 node_modules/lodash/fp/_baseConvert.js(379,14): error TS2339: Property 'runInContext' does not exist on type 'Function'.
 node_modules/lodash/fp/_baseConvert.js(516,33): error TS2339: Property 'placeholder' does not exist on type 'Function'.
@@ -310,19 +310,19 @@ node_modules/lodash/fp/_convertBrowser.js(15,12): error TS2304: Cannot find name
 node_modules/lodash/fp/_convertBrowser.js(15,38): error TS2304: Cannot find name '_'.
 node_modules/lodash/fp/_convertBrowser.js(16,3): error TS2304: Cannot find name '_'.
 node_modules/lodash/fp/_convertBrowser.js(16,22): error TS2304: Cannot find name '_'.
-node_modules/lodash/fp/array.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'chunk': (array: any[], size?: number | undefined, guard: any) => any[]; 'com...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/collection.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'countBy': Function; 'each': (collection: any, iteratee?: Function | undefine...' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/array.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'chunk': (array: any[], size?: number | undefined, guard: any) => any[]; 'compact': (array: any[]) => any[]; 'concat': (...args: any[]) => any[]; 'difference': Function; 'differenceBy': Function; 'differenceWith': Function; ... 58 more ...; 'zipWith': Function; }' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/collection.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'countBy': Function; 'each': (collection: any, iteratee?: Function | undefined) => any; 'eachRight': (collection: any, iteratee?: Function | undefined) => any; 'every': (collection: any, predicate?: Function | undefined, guard: any) => boolean; ... 23 more ...; 'sortBy': Function; }' is not assignable to parameter of type 'string'.
 node_modules/lodash/fp/convert.js(15,34): error TS2345: Argument of type 'Function | undefined' is not assignable to parameter of type 'Function'.
   Type 'undefined' is not assignable to type 'Function'.
 node_modules/lodash/fp/date.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'now': () => number; }' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/function.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'after': (n: number, func: Function) => Function; 'ary': (func: Function, n?:...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/lang.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'castArray': (...args: any[]) => any[]; 'clone': (value: any) => any; 'cloneD...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/math.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'add': Function; 'ceil': Function; 'divide': Function; 'floor': Function; 'ma...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/number.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'clamp': (number: number, lower?: number | undefined, upper: number) => numbe...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/object.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'assign': Function; 'assignIn': Function; 'assignInWith': Function; 'assignWi...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/seq.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'at': Function; 'chain': (value: any) => any; 'commit': () => any; 'lodash': ...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/string.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'camelCase': Function; 'capitalize': (string?: string | undefined) => string;...' is not assignable to parameter of type 'string'.
-node_modules/lodash/fp/util.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'attempt': Function; 'bindAll': Function; 'cond': (pairs: any[]) => Function;...' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/function.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'after': (n: number, func: Function) => Function; 'ary': (func: Function, n?: number | undefined, guard: any) => Function; 'before': (n: number, func: Function) => Function; ... 19 more ...; 'wrap': (value: any, wrapper?: Function | undefined) => Function; }' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/lang.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'castArray': (...args: any[]) => any[]; 'clone': (value: any) => any; 'cloneDeep': (value: any) => any; 'cloneDeepWith': (value: any, customizer?: Function | undefined) => any; 'cloneWith': (value: any, customizer?: Function | undefined) => any; ... 50 more ...; 'toString': (value: any) => string...' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/math.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'add': Function; 'ceil': Function; 'divide': Function; 'floor': Function; 'max': (array: any[]) => any; 'maxBy': (array: any[], iteratee?: Function | undefined) => any; 'mean': (array: any[]) => number; ... 7 more ...; 'sumBy': (array: any[], iteratee?: Function | undefined) => number; }' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/number.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'clamp': (number: number, lower?: number | undefined, upper: number) => number; 'inRange': (number: number, start?: number | undefined, end: number) => boolean; 'random': (lower?: number | undefined, upper?: number | undefined, floating?: boolean | undefined) => number; }' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/object.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'assign': Function; 'assignIn': Function; 'assignInWith': Function; 'assignWith': Function; 'at': Function; 'create': (prototype: any, properties?: any) => any; 'defaults': Function; 'defaultsDeep': Function; ... 38 more ...; 'valuesIn': (object: any) => any[]; }' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/seq.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'at': Function; 'chain': (value: any) => any; 'commit': () => any; 'lodash': typeof lodash; 'next': typeof wrapperNext; 'plant': (value: any) => any; 'reverse': () => any; 'tap': (value: any, interceptor: Function) => any; ... 5 more ...; 'wrapperChain': () => any; }' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/string.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'camelCase': Function; 'capitalize': (string?: string | undefined) => string; 'deburr': (string?: string | undefined) => string; 'endsWith': (string?: string | undefined, target?: string | undefined, position?: number | undefined) => boolean; ... 26 more ...; 'words': (string?: string | undefined...' is not assignable to parameter of type 'string'.
+node_modules/lodash/fp/util.js(2,26): error TS2345: Argument of type '{ [x: string]: any; 'attempt': Function; 'bindAll': Function; 'cond': (pairs: any[]) => Function; 'conforms': (source: any) => Function; 'constant': (value: any) => Function; 'defaultTo': (value: any, defaultValue: any) => any; ... 25 more ...; 'uniqueId': (prefix?: string | undefined) => string; }' is not assignable to parameter of type 'string'.
 node_modules/lodash/fp.js(2,18): error TS2554: Expected 3-4 arguments, but got 2.
 node_modules/lodash/includes.js(24,10): error TS1003: Identifier expected.
 node_modules/lodash/includes.js(24,10): error TS8024: JSDoc '@param' tag has name '', but there is no parameter with that name.
@@ -360,9 +360,9 @@ node_modules/lodash/pickBy.js(33,12): error TS2722: Cannot invoke an object whic
 node_modules/lodash/property.js(29,37): error TS2345: Argument of type 'string | symbol' is not assignable to parameter of type 'string'.
   Type 'symbol' is not assignable to type 'string'.
 node_modules/lodash/pullAllBy.js(29,34): error TS2554: Expected 0-1 arguments, but got 2.
-node_modules/lodash/reduce.js(48,10): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((array?: any[] | undefined, iteratee: Function, accumulator?: any, initAccum?: boolean | undefin...' has no compatible call signatures.
+node_modules/lodash/reduce.js(48,10): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((array?: any[] | undefined, iteratee: Function, accumulator?: any, initAccum?: boolean | undefined) => any) | ((collection: any, iteratee: Function, accumulator: any, initAccum: boolean, eachFunc: Function) => any)' has no compatible call signatures.
 node_modules/lodash/reduce.js(48,27): error TS2554: Expected 0-1 arguments, but got 2.
-node_modules/lodash/reduceRight.js(33,10): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((array?: any[] | undefined, iteratee: Function, accumulator?: any, initAccum?: boolean | undefin...' has no compatible call signatures.
+node_modules/lodash/reduceRight.js(33,10): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((array?: any[] | undefined, iteratee: Function, accumulator?: any, initAccum?: boolean | undefined) => any) | ((collection: any, iteratee: Function, accumulator: any, initAccum: boolean, eachFunc: Function) => any)' has no compatible call signatures.
 node_modules/lodash/reduceRight.js(33,27): error TS2554: Expected 0-1 arguments, but got 2.
 node_modules/lodash/reject.js(43,34): error TS2554: Expected 0-1 arguments, but got 2.
 node_modules/lodash/remove.js(41,15): error TS2554: Expected 0-1 arguments, but got 2.
@@ -407,7 +407,7 @@ node_modules/lodash/throttle.js(62,31): error TS2345: Argument of type '{ 'leadi
 node_modules/lodash/toLower.js(11,21): error TS8024: JSDoc '@param' tag has name 'string', but there is no parameter with that name.
 node_modules/lodash/toUpper.js(11,21): error TS8024: JSDoc '@param' tag has name 'string', but there is no parameter with that name.
 node_modules/lodash/transform.js(46,14): error TS2554: Expected 0-1 arguments, but got 2.
-node_modules/lodash/transform.js(59,3): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((array?: any[] | undefined, iteratee: Function) => any[]) | ((object: any, iteratee: Function) =...' has no compatible call signatures.
+node_modules/lodash/transform.js(59,3): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type '((array?: any[] | undefined, iteratee: Function) => any[]) | ((object: any, iteratee: Function) => any)' has no compatible call signatures.
 node_modules/lodash/transform.js(60,12): error TS2722: Cannot invoke an object which is possibly 'undefined'.
 node_modules/lodash/trim.js(20,10): error TS1003: Identifier expected.
 node_modules/lodash/trim.js(20,10): error TS8024: JSDoc '@param' tag has name '', but there is no parameter with that name.

tests/baselines/reference/user/npm.log

@@ -1,7 +1,7 @@
 Exit Code: 1
 Standard output:
-node_modules/npm/bin/npm-cli.js(6,13): error TS2551: Property 'echo' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: nu...'. Did you mean 'Echo'?
-node_modules/npm/bin/npm-cli.js(13,13): error TS2551: Property 'quit' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: nu...'. Did you mean 'Quit'?
+node_modules/npm/bin/npm-cli.js(6,13): error TS2551: Property 'echo' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: number; Item(n: number): string; }; ScriptFullName: string; Quit(exitCode?: number | undefined): number; ... 12 more ...; Sleep(intTime: number): void; }'. Did you mean 'Echo'?
+node_modules/npm/bin/npm-cli.js(13,13): error TS2551: Property 'quit' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: number; Item(n: number): string; }; ScriptFullName: string; Quit(exitCode?: number | undefined): number; ... 12 more ...; Sleep(intTime: number): void; }'. Did you mean 'Quit'?
 node_modules/npm/bin/npm-cli.js(47,7): error TS2339: Property 'argv' does not exist on type 'EventEmitter'.
 node_modules/npm/bin/npm-cli.js(48,11): error TS2339: Property 'deref' does not exist on type 'EventEmitter'.
 node_modules/npm/bin/npm-cli.js(48,21): error TS2339: Property 'argv' does not exist on type 'EventEmitter'.
@@ -492,11 +492,11 @@ node_modules/npm/lib/ls.js(152,11): error TS2339: Property 'config' does not exi
 node_modules/npm/lib/ls.js(180,22): error TS2339: Property 'config' does not exist on type 'EventEmitter'.
 node_modules/npm/lib/ls.js(191,52): error TS2339: Property 'globalDir' does not exist on type 'EventEmitter'.
 node_modules/npm/lib/ls.js(254,22): error TS2339: Property 'config' does not exist on type 'EventEmitter'.
-node_modules/npm/lib/ls.js(260,16): error TS2339: Property 'problems' does not exist on type 'string | { [x: string]: any; name: any; version: any; extraneous: boolean; problems: any; invalid...'.
+node_modules/npm/lib/ls.js(260,16): error TS2339: Property 'problems' does not exist on type 'string | { [x: string]: any; name: any; version: any; extraneous: boolean; problems: any; invalid: boolean; from: any; resolved: any; peerInvalid: boolean; dependencies: {}; } | { [x: string]: any; required: any; missing: boolean; } | { ...; }'.
   Property 'problems' does not exist on type 'string'.
-node_modules/npm/lib/ls.js(262,54): error TS2339: Property 'problems' does not exist on type 'string | { [x: string]: any; name: any; version: any; extraneous: boolean; problems: any; invalid...'.
+node_modules/npm/lib/ls.js(262,54): error TS2339: Property 'problems' does not exist on type 'string | { [x: string]: any; name: any; version: any; extraneous: boolean; problems: any; invalid: boolean; from: any; resolved: any; peerInvalid: boolean; dependencies: {}; } | { [x: string]: any; required: any; missing: boolean; } | { ...; }'.
   Property 'problems' does not exist on type 'string'.
-node_modules/npm/lib/ls.js(264,12): error TS2538: Type '{ [x: string]: any; name: any; version: any; extraneous: boolean; problems: any; invalid: boolean...' cannot be used as an index type.
+node_modules/npm/lib/ls.js(264,12): error TS2538: Type '{ [x: string]: any; name: any; version: any; extraneous: boolean; problems: any; invalid: boolean; from: any; resolved: any; peerInvalid: boolean; dependencies: {}; }' cannot be used as an index type.
 node_modules/npm/lib/ls.js(357,40): error TS2339: Property 'config' does not exist on type 'EventEmitter'.
 node_modules/npm/lib/ls.js(362,26): error TS2339: Property 'config' does not exist on type 'EventEmitter'.
 node_modules/npm/lib/ls.js(365,15): error TS2339: Property 'color' does not exist on type 'EventEmitter'.
@@ -515,8 +515,8 @@ node_modules/npm/lib/ls.js(522,18): error TS2339: Property 'config' does not exi
 node_modules/npm/lib/ls.js(528,19): error TS2339: Property 'config' does not exist on type 'EventEmitter'.
 node_modules/npm/lib/ls.js(538,12): error TS2339: Property 'config' does not exist on type 'EventEmitter'.
 node_modules/npm/lib/ls.js(544,56): error TS2339: Property 'globalDir' does not exist on type 'EventEmitter'.
-node_modules/npm/lib/npm.js(5,13): error TS2551: Property 'echo' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: nu...'. Did you mean 'Echo'?
-node_modules/npm/lib/npm.js(12,13): error TS2551: Property 'quit' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: nu...'. Did you mean 'Quit'?
+node_modules/npm/lib/npm.js(5,13): error TS2551: Property 'echo' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: number; Item(n: number): string; }; ScriptFullName: string; Quit(exitCode?: number | undefined): number; ... 12 more ...; Sleep(intTime: number): void; }'. Did you mean 'Echo'?
+node_modules/npm/lib/npm.js(12,13): error TS2551: Property 'quit' does not exist on type '{ Echo(s: any): void; StdErr: TextStreamWriter; StdOut: TextStreamWriter; Arguments: { length: number; Item(n: number): string; }; ScriptFullName: string; Quit(exitCode?: number | undefined): number; ... 12 more ...; Sleep(intTime: number): void; }'. Did you mean 'Quit'?
 node_modules/npm/lib/npm.js(30,14): error TS2345: Argument of type '"log"' is not assignable to parameter of type 'Signals'.
 node_modules/npm/lib/npm.js(58,7): error TS2339: Property 'config' does not exist on type 'EventEmitter'.
 node_modules/npm/lib/npm.js(68,7): error TS2339: Property 'commands' does not exist on type 'EventEmitter'.
@@ -800,7 +800,7 @@ node_modules/npm/lib/utils/error-handler.js(146,27): error TS2339: Property 'con
 node_modules/npm/lib/utils/error-handler.js(166,14): error TS2339: Property 'code' does not exist on type 'Error'.
 node_modules/npm/lib/utils/error-handler.js(167,16): error TS2339: Property 'code' does not exist on type 'Error'.
 node_modules/npm/lib/utils/error-handler.js(168,8): error TS2339: Property 'code' does not exist on type 'Error'.
-node_modules/npm/lib/utils/error-handler.js(186,40): error TS2345: Argument of type '{ (value: any, replacer?: ((key: string, value: any) => any) | undefined, space?: string | number...' is not assignable to parameter of type '(value: string, index: number, array: string[]) => string'.
+node_modules/npm/lib/utils/error-handler.js(186,40): error TS2345: Argument of type '{ (value: any, replacer?: ((key: string, value: any) => any) | undefined, space?: string | number | undefined): string; (value: any, replacer?: (string | number)[] | null | undefined, space?: string | ... 1 more ... | undefined): string; }' is not assignable to parameter of type '(value: string, index: number, array: string[]) => string'.
   Types of parameters 'replacer' and 'index' are incompatible.
     Type 'number' is not assignable to type '((key: string, value: any) => any) | undefined'.
 node_modules/npm/lib/utils/error-handler.js(188,33): error TS2339: Property 'version' does not exist on type 'EventEmitter'.
@@ -1253,8 +1253,8 @@ node_modules/npm/test/tap/init-interrupt.js(8,29): error TS2307: Cannot find mod
 node_modules/npm/test/tap/init-interrupt.js(28,7): error TS2339: Property 'load' does not exist on type 'EventEmitter'.
 node_modules/npm/test/tap/install-actions.js(4,20): error TS2307: Cannot find module 'tap'.
 node_modules/npm/test/tap/install-actions.js(13,7): error TS2339: Property 'load' does not exist on type 'EventEmitter'.
-node_modules/npm/test/tap/install-actions.js(108,27): error TS2345: Argument of type '{ [x: string]: any; path: string; package: { [x: string]: any; dependencies: { [x: string]: any; ...' is not assignable to parameter of type '{ [x: string]: any; name: string; path: string; package: { [x: string]: any; scripts: { [x: strin...'.
-  Property 'name' is missing in type '{ [x: string]: any; path: string; package: { [x: string]: any; dependencies: { [x: string]: any; ...'.
+node_modules/npm/test/tap/install-actions.js(108,27): error TS2345: Argument of type '{ [x: string]: any; path: string; package: { [x: string]: any; dependencies: { [x: string]: any; b: string; }; optionalDependencies: { [x: string]: any; a: string; }; }; children: ({ [x: string]: any; name: string; path: string; package: { [x: string]: any; scripts: { ...; }; dependencies: { ...; }; }; isTop: boolea...' is not assignable to parameter of type '{ [x: string]: any; name: string; path: string; package: { [x: string]: any; scripts: { [x: string]: any; postinstall: string; }; dependencies: { [x: string]: any; b: string; }; }; isTop: boolean; }'.
+  Property 'name' is missing in type '{ [x: string]: any; path: string; package: { [x: string]: any; dependencies: { [x: string]: any; b: string; }; optionalDependencies: { [x: string]: any; a: string; }; }; children: ({ [x: string]: any; name: string; path: string; package: { [x: string]: any; scripts: { ...; }; dependencies: { ...; }; }; isTop: boolea...'.
 node_modules/npm/test/tap/install-at-locally.js(7,20): error TS2307: Cannot find module 'tap'.
 node_modules/npm/test/tap/install-bad-dep-format.js(7,20): error TS2307: Cannot find module 'tap'.
 node_modules/npm/test/tap/install-bad-man.js(7,20): error TS2307: Cannot find module 'tap'.
@@ -1653,8 +1653,8 @@ node_modules/npm/test/tap/unit-deps-earliestInstallable.js(3,29): error TS2307:
 node_modules/npm/test/tap/unit-deps-removeObsoleteDep.js(2,20): error TS2307: Cannot find module 'tap'.
 node_modules/npm/test/tap/unit-deps-removeObsoleteDep.js(3,29): error TS2307: Cannot find module 'require-inject'.
 node_modules/npm/test/tap/unit-deps-removeObsoleteDep.js(32,26): error TS2345: Argument of type '{ [x: string]: any; requires: { [x: string]: any; requiredBy: never[]; }[]; }' is not assignable to parameter of type 'never'.
-node_modules/npm/test/tap/unit-deps-removeObsoleteDep.js(40,26): error TS2345: Argument of type '{ [x: string]: any; requires: { [x: string]: any; requiredBy: { [x: string]: any; isTop: boolean;...' is not assignable to parameter of type '{ [x: string]: any; isTop: boolean; }'.
-  Property 'isTop' is missing in type '{ [x: string]: any; requires: { [x: string]: any; requiredBy: { [x: string]: any; isTop: boolean;...'.
+node_modules/npm/test/tap/unit-deps-removeObsoleteDep.js(40,26): error TS2345: Argument of type '{ [x: string]: any; requires: { [x: string]: any; requiredBy: { [x: string]: any; isTop: boolean; }[]; }[]; }' is not assignable to parameter of type '{ [x: string]: any; isTop: boolean; }'.
+  Property 'isTop' is missing in type '{ [x: string]: any; requires: { [x: string]: any; requiredBy: { [x: string]: any; isTop: boolean; }[]; }[]; }'.
 node_modules/npm/test/tap/unit-deps-replaceModule.js(2,20): error TS2307: Cannot find module 'tap'.
 node_modules/npm/test/tap/unit-deps-replaceModule.js(6,7): error TS2339: Property 'load' does not exist on type 'EventEmitter'.
 node_modules/npm/test/tap/unit-module-name.js(2,20): error TS2307: Cannot find module 'tap'.

tests/baselines/reference/user/prettier.log

@@ -22,18 +22,18 @@ src/language-css/parser-postcss.js(100,30): error TS2345: Argument of type 'any'
 src/language-css/parser-postcss.js(104,28): error TS2345: Argument of type '{ [x: string]: any; groups: never[]; type: string; }' is not assignable to parameter of type 'never'.
 src/language-css/parser-postcss.js(407,32): error TS2531: Object is possibly 'null'.
 src/language-css/printer-postcss.js(3,30): error TS2307: Cannot find module 'html-tag-names'.
-src/language-handlebars/parser-glimmer.js(27,26): error TS2345: Argument of type '{ plugins: { ast: (() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): voi...' is not assignable to parameter of type 'PreprocessOptions'.
+src/language-handlebars/parser-glimmer.js(27,26): error TS2345: Argument of type '{ plugins: { ast: (() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any): void; }; })[]; }; }' is not assignable to parameter of type 'PreprocessOptions'.
   Types of property 'plugins' are incompatible.
-    Type '{ ast: (() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementN...' is not assignable to type '{ ast?: ASTPluginBuilder[] | undefined; }'.
+    Type '{ ast: (() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any): void; }; })[]; }' is not assignable to type '{ ast?: ASTPluginBuilder[] | undefined; }'.
       Types of property 'ast' are incompatible.
-        Type '(() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(nod...' is not assignable to type 'ASTPluginBuilder[]'.
-          Type '() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node...' is not assignable to type 'ASTPluginBuilder'.
-            Type '{ [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any)...' is not assignable to type 'ASTPlugin'.
-              Property 'name' is missing in type '{ [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any)...'.
+        Type '(() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any): void; }; })[]' is not assignable to type 'ASTPluginBuilder[]'.
+          Type '() => { [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any): void; }; }' is not assignable to type 'ASTPluginBuilder'.
+            Type '{ [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any): void; }; }' is not assignable to type 'ASTPlugin'.
+              Property 'name' is missing in type '{ [x: string]: any; visitor: { [x: string]: any; Program(node: any): void; ElementNode(node: any): void; }; }'.
 src/language-handlebars/printer-glimmer.js(270,7): error TS2554: Expected 0-1 arguments, but got 2.
 src/language-js/printer-estree.js(99,9): error TS2322: Type '{ [x: string]: any; type: string; }' is not assignable to type '{ [x: string]: any; type: string; parts: any; }'.
   Property 'parts' is missing in type '{ [x: string]: any; type: string; }'.
-src/language-js/printer-estree.js(302,9): error TS2345: Argument of type '{ [x: string]: any; type: string; parts: any; } | { [x: string]: any; type: string; contents: any...' is not assignable to parameter of type 'ConcatArray<never>'.
+src/language-js/printer-estree.js(302,9): error TS2345: Argument of type '{ [x: string]: any; type: string; parts: any; } | { [x: string]: any; type: string; contents: any; }' is not assignable to parameter of type 'ConcatArray<never>'.
   Type '{ [x: string]: any; type: string; parts: any; }' is not assignable to type 'ConcatArray<never>'.
     Property 'length' is missing in type '{ [x: string]: any; type: string; parts: any; }'.
 src/language-js/printer-estree.js(1224,28): error TS2345: Argument of type '{ [x: string]: any; type: string; parts: any; }' is not assignable to parameter of type 'string | ConcatArray<string>'.
@@ -46,7 +46,7 @@ src/language-js/printer-estree.js(1605,18): error TS2345: Argument of type '"whi
 src/language-js/printer-estree.js(1614,9): error TS2345: Argument of type '")"' is not assignable to parameter of type '{ [x: string]: any; type: string; contents: any; break: boolean; expandedStates: any; }'.
 src/language-js/printer-estree.js(3293,23): error TS2532: Object is possibly 'undefined'.
 src/language-js/printer-estree.js(3294,24): error TS2532: Object is possibly 'undefined'.
-src/language-js/printer-estree.js(3647,5): error TS2345: Argument of type '"" | { [x: string]: any; type: string; parts: any; } | { [x: string]: any; type: string; contents...' is not assignable to parameter of type 'string'.
+src/language-js/printer-estree.js(3647,5): error TS2345: Argument of type '"" | { [x: string]: any; type: string; parts: any; } | { [x: string]: any; type: string; contents: any; }' is not assignable to parameter of type 'string'.
   Type '{ [x: string]: any; type: string; parts: any; }' is not assignable to type 'string'.
 src/language-js/printer-estree.js(3651,16): error TS2345: Argument of type '{ [x: string]: any; type: string; parts: any; }' is not assignable to parameter of type 'string'.
 src/language-js/printer-estree.js(3693,9): error TS2345: Argument of type '{ [x: string]: any; type: string; parts: any; }' is not assignable to parameter of type 'string'.
@@ -67,29 +67,29 @@ src/language-vue/parser-vue.js(54,23): error TS2345: Argument of type '(m: strin
 src/language-vue/parser-vue.js(180,34): error TS2339: Property 'toLowerCase' does not exist on type 'never'.
 src/language-vue/parser-vue.js(244,26): error TS2345: Argument of type 'any' is not assignable to parameter of type 'never'.
 src/language-vue/parser-vue.js(393,25): error TS2345: Argument of type '{ [x: string]: any; tag: any; attrs: any; unary: any; start: any; children: never[]; }' is not assignable to parameter of type 'never'.
-src/language-vue/parser-vue.js(398,23): error TS2345: Argument of type '{ [x: string]: any; tag: any; attrs: any; unary: any; start: any; children: never[]; }' is not assignable to parameter of type '{ [x: string]: any; tag: string; attrs: never[]; unary: boolean; start: number; contentStart: num...'.
+src/language-vue/parser-vue.js(398,23): error TS2345: Argument of type '{ [x: string]: any; tag: any; attrs: any; unary: any; start: any; children: never[]; }' is not assignable to parameter of type '{ [x: string]: any; tag: string; attrs: never[]; unary: boolean; start: number; contentStart: number; contentEnd: any; end: any; children: never[]; comments: never[]; }'.
   Property 'contentStart' is missing in type '{ [x: string]: any; tag: any; attrs: any; unary: any; start: any; children: never[]; }'.
-src/language-vue/parser-vue.js(399,9): error TS2322: Type '{ [x: string]: any; tag: any; attrs: any; unary: any; start: any; children: never[]; }' is not assignable to type '{ [x: string]: any; tag: string; attrs: never[]; unary: boolean; start: number; contentStart: num...'.
+src/language-vue/parser-vue.js(399,9): error TS2322: Type '{ [x: string]: any; tag: any; attrs: any; unary: any; start: any; children: never[]; }' is not assignable to type '{ [x: string]: any; tag: string; attrs: never[]; unary: boolean; start: number; contentStart: number; contentEnd: any; end: any; children: never[]; comments: never[]; }'.
 src/main/core-options.js(51,43): error TS1005: '}' expected.
-src/main/core-options.js(63,5): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; range: { start: number; end: num...' is not assignable to type 'OptionInfo'.
+src/main/core-options.js(63,5): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; range: { start: number; end: number; step: number; }; description: any; cliCategory: string; }' is not assignable to type 'OptionInfo'.
   Object literal may only specify known properties, and 'cliCategory' does not exist in type 'OptionInfo'.
-src/main/core-options.js(69,5): error TS2322: Type 'undefined' is not assignable to type 'string | number | boolean | { since: string; value: string | number | boolean; }[] | [{ value: (s...'.
-src/main/core-options.js(82,5): error TS2322: Type '{ since: string; category: string; type: "boolean"; default: false; description: string; cliCateg...' is not assignable to type 'OptionInfo'.
+src/main/core-options.js(69,5): error TS2322: Type 'undefined' is not assignable to type 'string | number | boolean | { since: string; value: string | number | boolean; }[] | [{ value: (string | number | boolean)[]; }]'.
+src/main/core-options.js(82,5): error TS2322: Type '{ since: string; category: string; type: "boolean"; default: false; description: string; cliCategory: string; }' is not assignable to type 'OptionInfo'.
   Object literal may only specify known properties, and 'cliCategory' does not exist in type 'OptionInfo'.
-src/main/core-options.js(92,5): error TS2322: Type '({ [x: string]: any; value: string; description: string; } | { [x: string]: any; value: string; s...' is not assignable to type 'OptionChoiceInfo'.
-  Property 'value' is missing in type '({ [x: string]: any; value: string; description: string; } | { [x: string]: any; value: string; s...'.
-src/main/core-options.js(122,5): error TS2322: Type '{ since: string; type: "path"; array: true; default: [{ value: never[]; }]; category: string; des...' is not assignable to type 'OptionInfo'.
+src/main/core-options.js(92,5): error TS2322: Type '({ [x: string]: any; value: string; description: string; } | { [x: string]: any; value: string; since: string; description: string; } | { [x: string]: any; value: string; since: string; description: string; deprecated: string; redirect: string; })[]' is not assignable to type 'OptionChoiceInfo'.
+  Property 'value' is missing in type '({ [x: string]: any; value: string; description: string; } | { [x: string]: any; value: string; since: string; description: string; } | { [x: string]: any; value: string; since: string; description: string; deprecated: string; redirect: string; })[]'.
+src/main/core-options.js(122,5): error TS2322: Type '{ since: string; type: "path"; array: true; default: [{ value: never[]; }]; category: string; description: string; exception: (value: any) => boolean; cliName: string; cliCategory: string; }' is not assignable to type 'OptionInfo'.
   Object literal may only specify known properties, and 'cliName' does not exist in type 'OptionInfo'.
-src/main/core-options.js(125,3): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; description: string; range: { st...' is not assignable to type 'OptionInfo'.
-  Property 'array' is missing in type '{ since: string; category: string; type: "int"; default: number; description: string; range: { st...'.
-src/main/core-options.js(144,5): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; range: { start: number; end: num...' is not assignable to type 'OptionInfo'.
+src/main/core-options.js(125,3): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; description: string; range: { start: number; end: number; step: number; }; }' is not assignable to type 'OptionInfo'.
+  Property 'array' is missing in type '{ since: string; category: string; type: "int"; default: number; description: string; range: { start: number; end: number; step: number; }; }'.
+src/main/core-options.js(144,5): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; range: { start: number; end: number; step: number; }; description: any; cliCategory: string; }' is not assignable to type 'OptionInfo'.
   Object literal may only specify known properties, and 'cliCategory' does not exist in type 'OptionInfo'.
-src/main/core-options.js(157,5): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; range: { start: number; end: num...' is not assignable to type 'OptionInfo'.
+src/main/core-options.js(157,5): error TS2322: Type '{ since: string; category: string; type: "int"; default: number; range: { start: number; end: number; step: number; }; description: any; cliCategory: string; }' is not assignable to type 'OptionInfo'.
   Object literal may only specify known properties, and 'cliCategory' does not exist in type 'OptionInfo'.
-src/main/core-options.js(168,5): error TS2322: Type '{ since: string; category: string; type: "boolean"; default: false; description: any; cliCategory...' is not assignable to type 'OptionInfo'.
+src/main/core-options.js(168,5): error TS2322: Type '{ since: string; category: string; type: "boolean"; default: false; description: any; cliCategory: string; }' is not assignable to type 'OptionInfo'.
   Object literal may only specify known properties, and 'cliCategory' does not exist in type 'OptionInfo'.
-src/main/core-options.js(170,3): error TS2322: Type '{ type: "int"; category: string; default: number; description: string; range: { start: number; en...' is not assignable to type 'OptionInfo'.
-  Property 'since' is missing in type '{ type: "int"; category: string; default: number; description: string; range: { start: number; en...'.
+src/main/core-options.js(170,3): error TS2322: Type '{ type: "int"; category: string; default: number; description: string; range: { start: number; end: number; step: number; }; }' is not assignable to type 'OptionInfo'.
+  Property 'since' is missing in type '{ type: "int"; category: string; default: number; description: string; range: { start: number; end: number; step: number; }; }'.
 src/main/core-options.js(182,5): error TS2322: Type 'string' is not assignable to type 'boolean | null'.
 src/main/core-options.js(187,3): error TS2322: Type '{ since: string; category: string; type: "boolean"; default: false; description: string; }' is not assignable to type 'OptionInfo'.
   Property 'array' is missing in type '{ since: string; category: string; type: "boolean"; default: false; description: string; }'.

tests/baselines/reference/user/uglify-js.log

@@ -2,41 +2,41 @@ Exit Code: 1
 Standard output:
 node_modules/uglify-js/lib/ast.js(209,23): error TS2554: Expected 0 arguments, but got 1.
 node_modules/uglify-js/lib/ast.js(331,33): error TS2339: Property 'transform' does not exist on type 'string'.
-node_modules/uglify-js/lib/ast.js(872,5): error TS2322: Type '{ [x: string]: any; _visit: (node: any, descend: any) => any; parent: (n: any) => any; push: type...' is not assignable to type 'TreeWalker'.
+node_modules/uglify-js/lib/ast.js(872,5): error TS2322: Type '{ [x: string]: any; _visit: (node: any, descend: any) => any; parent: (n: any) => any; push: typeof push; pop: typeof pop; self: () => any; find_parent: (type: any) => any; has_directive: (type: any) => any; loopcontrol_target: (node: any) => any; in_boolean_context: () => boolean | undefined; }' is not assignable to type 'TreeWalker'.
   Object literal may only specify known properties, but '_visit' does not exist in type 'TreeWalker'. Did you mean to write 'visit'?
 node_modules/uglify-js/lib/compress.js(166,27): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(503,26): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(820,18): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(1075,38): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
-node_modules/uglify-js/lib/compress.js(1089,51): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type 'true | ((node: any) => any)' has no compatible call signatures.
-node_modules/uglify-js/lib/compress.js(1153,53): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
-node_modules/uglify-js/lib/compress.js(1195,112): error TS2532: Object is possibly 'undefined'.
-node_modules/uglify-js/lib/compress.js(1196,29): error TS2532: Object is possibly 'undefined'.
-node_modules/uglify-js/lib/compress.js(1205,87): error TS2322: Type 'false' is not assignable to type 'number'.
-node_modules/uglify-js/lib/compress.js(1213,29): error TS2322: Type 'false' is not assignable to type 'never'.
-node_modules/uglify-js/lib/compress.js(1316,38): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(1411,38): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
-node_modules/uglify-js/lib/compress.js(1507,27): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(1539,26): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(1953,44): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(2145,19): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(2464,27): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(3204,23): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(3217,33): error TS2322: Type '"f"' is not assignable to type 'boolean'.
-node_modules/uglify-js/lib/compress.js(3356,18): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(3411,14): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(3420,29): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
-node_modules/uglify-js/lib/compress.js(3678,23): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(3699,24): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
-node_modules/uglify-js/lib/compress.js(3709,28): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
-node_modules/uglify-js/lib/compress.js(3868,21): error TS2403: Subsequent variable declarations must have the same type.  Variable 'defs' must be of type 'Dictionary & { [x: string]: any; set: (key: any, val: any) => any; add: (key: any, val: any) => a...', but here has type 'any'.
-node_modules/uglify-js/lib/compress.js(3920,17): error TS2447: The '|=' operator is not allowed for boolean types. Consider using '||' instead.
-node_modules/uglify-js/lib/compress.js(3945,30): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(500,26): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(817,18): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(1072,38): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
+node_modules/uglify-js/lib/compress.js(1086,51): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type 'true | ((node: any) => any)' has no compatible call signatures.
+node_modules/uglify-js/lib/compress.js(1150,53): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
+node_modules/uglify-js/lib/compress.js(1192,112): error TS2532: Object is possibly 'undefined'.
+node_modules/uglify-js/lib/compress.js(1193,29): error TS2532: Object is possibly 'undefined'.
+node_modules/uglify-js/lib/compress.js(1202,87): error TS2322: Type 'false' is not assignable to type 'number'.
+node_modules/uglify-js/lib/compress.js(1210,29): error TS2322: Type 'false' is not assignable to type 'never'.
+node_modules/uglify-js/lib/compress.js(1313,38): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(1408,38): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
+node_modules/uglify-js/lib/compress.js(1504,27): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(1536,26): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(1950,44): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(2142,19): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(2461,27): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(3201,23): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(3214,33): error TS2322: Type '"f"' is not assignable to type 'boolean'.
+node_modules/uglify-js/lib/compress.js(3353,18): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(3408,14): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(3417,29): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
+node_modules/uglify-js/lib/compress.js(3676,23): error TS2554: Expected 0 arguments, but got 1.
+node_modules/uglify-js/lib/compress.js(3697,24): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
+node_modules/uglify-js/lib/compress.js(3707,28): error TS2339: Property 'parent' does not exist on type 'TreeTransformer'.
+node_modules/uglify-js/lib/compress.js(3866,21): error TS2403: Subsequent variable declarations must have the same type.  Variable 'defs' must be of type 'Dictionary & { [x: string]: any; set: (key: any, val: any) => any; add: (key: any, val: any) => any; get: (key: any) => any; del: (key: any) => any; has: (key: any) => boolean; each: (f: any) => void; size: () => any; map: (f: any) => any[]; clone: () => Dictionary & any; toObject: () => any; }', but here has type 'any'.
+node_modules/uglify-js/lib/compress.js(3918,17): error TS2447: The '|=' operator is not allowed for boolean types. Consider using '||' instead.
+node_modules/uglify-js/lib/compress.js(3974,30): error TS2554: Expected 0 arguments, but got 1.
 node_modules/uglify-js/lib/compress.js(4083,18): error TS2554: Expected 0 arguments, but got 1.
 node_modules/uglify-js/lib/compress.js(4382,17): error TS2403: Subsequent variable declarations must have the same type.  Variable 'body' must be of type 'any[]', but here has type 'any'.
 node_modules/uglify-js/lib/compress.js(4466,22): error TS2554: Expected 0 arguments, but got 1.
 node_modules/uglify-js/lib/compress.js(4816,30): error TS2554: Expected 0 arguments, but got 1.
-node_modules/uglify-js/lib/compress.js(4823,25): error TS2403: Subsequent variable declarations must have the same type.  Variable 'code' must be of type 'string', but here has type '{ [x: string]: any; get: () => string; toString: () => string; indent: () => void; indentation: (...'.
+node_modules/uglify-js/lib/compress.js(4823,25): error TS2403: Subsequent variable declarations must have the same type.  Variable 'code' must be of type 'string', but here has type '{ [x: string]: any; get: () => string; toString: () => string; indent: () => void; indentation: () => number; current_width: () => number; should_break: () => boolean; has_parens: () => boolean; newline: () => void; print: (str: any) => void; ... 24 more ...; parent: (n: any) => any; }'.
 node_modules/uglify-js/lib/compress.js(4827,36): error TS2532: Object is possibly 'undefined'.
 node_modules/uglify-js/lib/compress.js(4832,41): error TS2339: Property 'get' does not exist on type 'string'.
 node_modules/uglify-js/lib/compress.js(5319,18): error TS2454: Variable 'is_strict_comparison' is used before being assigned.
@@ -82,9 +82,9 @@ node_modules/uglify-js/lib/parse.js(1430,20): error TS2531: Object is possibly '
 node_modules/uglify-js/lib/parse.js(1516,48): error TS2531: Object is possibly 'null'.
 node_modules/uglify-js/lib/parse.js(1542,35): error TS2531: Object is possibly 'null'.
 node_modules/uglify-js/lib/parse.js(1587,52): error TS2531: Object is possibly 'null'.
-node_modules/uglify-js/lib/propmangle.js(61,18): error TS2339: Property 'prototype' does not exist on type 'ObjectConstructor | FunctionConstructor | StringConstructor | BooleanConstructor | NumberConstruc...'.
+node_modules/uglify-js/lib/propmangle.js(61,18): error TS2339: Property 'prototype' does not exist on type 'ObjectConstructor | FunctionConstructor | StringConstructor | BooleanConstructor | NumberConstructor | Math | DateConstructor | RegExpConstructor | ErrorConstructor | ArrayConstructor'.
   Property 'prototype' does not exist on type 'Math'.
-node_modules/uglify-js/lib/propmangle.js(62,45): error TS2339: Property 'prototype' does not exist on type 'ObjectConstructor | FunctionConstructor | StringConstructor | BooleanConstructor | NumberConstruc...'.
+node_modules/uglify-js/lib/propmangle.js(62,45): error TS2339: Property 'prototype' does not exist on type 'ObjectConstructor | FunctionConstructor | StringConstructor | BooleanConstructor | NumberConstructor | Math | DateConstructor | RegExpConstructor | ErrorConstructor | ArrayConstructor'.
   Property 'prototype' does not exist on type 'Math'.
 node_modules/uglify-js/lib/propmangle.js(75,14): error TS2554: Expected 0 arguments, but got 1.
 node_modules/uglify-js/lib/propmangle.js(85,15): error TS2554: Expected 0 arguments, but got 1.

tests/cases/compiler/destructuringTempOccursAfterPrologue.ts

@@ -1,4 +1,5 @@
 function test(p: any) {
     'use strict';
+    'use strong';
     p = { prop: p } = p;
 }

tests/cases/compiler/functionParameterArityMismatch.ts

@@ -0,0 +1,14 @@
+declare function f1(a: number);
+declare function f1(a: number, b: number, c: number);
+f1();
+f1(1, 2);
+f1(1, 2, 3, 4);
+
+declare function f2();
+declare function f2(a: number, b: number);
+declare function f2(a: number, b: number, c: number, d: number);
+declare function f2(a: number, b: number, c: number, d: number, e: number, f: number);
+f2(1);
+f2(1, 2, 3);
+f2(1, 2, 3, 4, 5);
+f2(1, 2, 3, 4, 5, 6, 7);

tests/cases/conformance/jsdoc/checkJsdocTypeTag5.ts

@@ -16,3 +16,23 @@ function i(x) { return x }
 var j = x => x
 /** @type {{ (x: number): string }} */
 var k = function (x) { return x }
+
+
+/** @typedef {(x: 'hi' | 'bye') => 0 | 1 | 2} Argle */
+/** @type {Argle} */
+function blargle(s) {
+    return 0;
+}
+
+/** @type {0 | 1 | 2} - assignment should not error */
+var zeroonetwo = blargle('hi')
+
+/** @typedef {{(s: string): 0 | 1; (b: boolean): 2 | 3 }} Gioconda */
+
+/** @type {Gioconda} */
+function monaLisa(sb) {
+    return typeof sb === 'string' ? 1 : 2;
+}
+
+/** @type {2 | 3} - overloads are not supported, so there will be an error */
+var twothree = monaLisa(false);

tests/cases/conformance/jsdoc/checkJsdocTypeTag6.ts

@@ -0,0 +1,13 @@
+// @checkJs: true
+// @allowJs: true
+// @noEmit: true
+// @Filename: test.js
+
+/** @type {number} */
+function f() {
+    return 1
+}
+
+/** @type {{ prop: string }} */
+var g = function (prop) {
+}

tests/cases/conformance/types/conditional/conditionalTypesExcessProperties.ts

@@ -0,0 +1,10 @@
+type Something<T> = { test: string } &  (T extends object ? {
+    arg: T
+} : {
+    arg?: undefined
+    });
+
+function testFunc2<A extends object>(a: A, sa: Something<A>) {
+    sa = { test: 'hi', arg: a }; // not excess (but currently still not assignable)
+    sa = { test: 'bye', arg: a, arr: a } // excess
+}

tests/cases/fourslash/automaticConstructorToggling.ts

@@ -28,7 +28,7 @@ edit.deleteAtCaret('constructor(val: T) { }'.length);
 verify.quickInfos({
     Asig: "constructor A<string>(): A<string>",
     Bsig: "constructor B<string>(val: string): B<string>",
-    Csig: "constructor C<T>(): C<T>", // Cannot resolve signature
+    Csig: "constructor C<{}>(): C<{}>", // Cannot resolve signature
     Dsig: "constructor D<string>(val: string): D<string>" // Cannot resolve signature
 });
 
@@ -37,6 +37,6 @@ edit.deleteAtCaret("val: T".length);
 verify.quickInfos({
     Asig: "constructor A<string>(): A<string>",
     Bsig: "constructor B<string>(val: string): B<string>",
-    Csig: "constructor C<T>(): C<T>", // Cannot resolve signature
+    Csig: "constructor C<{}>(): C<{}>", // Cannot resolve signature
     Dsig: "constructor D<string>(): D<string>"
 });

tests/cases/fourslash/codeFixCannotFindModule.ts

@@ -10,17 +10,21 @@
 ////import * as abs from "abs";
 ////abs;
 
+// @Filename: /b.ts
+////const x: import("abs").T = 0;
+
 test.setTypesRegistry({
     "abs": undefined,
 });
 
-goTo.file("/a.ts");
-
-verify.codeFixAvailable([{
-    description: "Install '@types/abs'",
-    commands: [{
-        type: "install package",
-        file: "/a.ts",
-        packageName: "@types/abs",
-    }],
-}]);
+for (const file of ["/a.ts", "/b.ts"]) {
+    goTo.file(file);
+    verify.codeFixAvailable([{
+        description: "Install '@types/abs'",
+        commands: [{
+            type: "install package",
+            file,
+            packageName: "@types/abs",
+        }],
+    }]);
+}

tests/cases/fourslash/codeFixUnusedIdentifier_all_delete_js.ts

@@ -0,0 +1,63 @@
+/// <reference path='fourslash.ts' />
+
+// @allowJs: true
+
+// @Filename: /a.js
+/////** @template T Parameter doc comment */
+////function f() {}
+////
+/////**
+//// * Doc
+//// * @template T Comment
+//// */
+////function g() {}
+////
+/////**
+//// * Doc
+//// * @template T Comment
+//// * @template U Comment
+//// */
+////function h() {}
+////
+/////** @template T Comment @return {void} */
+////function i() {}
+////
+/////**
+////Doc
+////@template T comment
+////@template U comment
+////@param {number} x
+////*/
+////function j(x) { return x; }
+
+verify.codeFixAll({
+    fixId: "unusedIdentifier_delete",
+    fixAllDescription: "Delete all unused declarations",
+    newFileContent:
+`
+function f() {}
+
+/**
+ * Doc
+ * Comment
+ */
+function g() {}
+
+/**
+ * Doc
+ * Comment
+ * Comment
+ */
+function h() {}
+
+/** Comment @return {void} */
+function i() {}
+
+/**
+Doc
+comment
+comment
+@param {number} x
+*/
+function j(x) { return x; }`,
+});

tests/cases/fourslash/completionsCombineOverloads.ts

@@ -0,0 +1,9 @@
+/// <reference path="fourslash.ts" />
+
+////interface A { a: number }
+////interface B { b: number }
+////declare function f(a: A): void;
+////declare function f(b: B): void;
+////f({ /**/ });
+
+verify.completions({ marker: "", exact: ["a", "b"] });

tests/cases/fourslash/completionsCombineOverloads_restParameter.ts

@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+////interface A { a: number }
+////interface B { b: number }
+////interface C { c: number }
+////declare function f(a: A): void;
+////declare function f(...bs: B[]): void;
+////declare function f(...cs: C[]): void;
+////f({ /*1*/ });
+////f({ a: 1 }, { /*2*/ });
+
+verify.completions(
+    { marker: "1", exact: ["a", "b", "c"] },
+    { marker: "2", exact: ["b", "c"] },
+);

tests/cases/fourslash/completionsCombineOverloads_returnType.ts

@@ -0,0 +1,9 @@
+/// <reference path="fourslash.ts" />
+
+////interface A { a: number }
+////interface B { b: number }
+////declare function f(n: number): A;
+////declare function f(s: string): B;
+////f()./**/
+
+verify.completions({ marker: "", exact: ["a", "b"] });

tests/cases/fourslash/completionsIsPossiblyTypeArgumentPosition.ts

@@ -0,0 +1,38 @@
+/// <reference path="fourslash.ts" />
+
+////const x = 0;
+////type T = number;
+////function f(x: number) {}
+////function g<T>(x: T) {}
+////class C<T> {}
+
+////x + {| "valueOnly": true |}
+////x < {| "valueOnly": true |}
+////f < {| "valueOnly": true |}
+////g < {| "valueOnly": false |}
+////const something: C<{| "valueOnly": false |};
+////const something2: C<C<{| "valueOnly": false |};
+////new C<{| "valueOnly": false |};
+////new C<C<{| "valueOnly": false |};
+////
+////declare const callAndConstruct: { new<T>(): callAndConstruct<T>; <T>(): string; };
+////interface callAndConstruct<T> {}
+////new callAndConstruct<callAndConstruct</*callAndConstruct*/
+
+for (const marker of test.markers()) {
+    if (marker.data && marker.data.valueOnly) {
+        verify.completions({ marker, includes: "x", excludes: "T" });
+    }
+    else {
+        verify.completions({ marker, includes: ["x", "T"] });
+    }
+}
+
+verify.signatureHelp({
+    marker: "callAndConstruct",
+    text: "callAndConstruct<T>(): string",
+    parameterName: "T",
+    parameterSpan: "T",
+    parameterCount: 1,
+    argumentCount: 1,
+});

tests/cases/fourslash/fourslash.ts

@@ -184,7 +184,7 @@ declare namespace FourSlashInterface {
             index?: number,
             preferences?: UserPreferences,
         });
-        codeFixAvailable(options?: Array<{ description: string, actions?: Array<{ type: string, data: {} }>, commands?: {}[] }>): void;
+        codeFixAvailable(options?: ReadonlyArray<VerifyCodeFixAvailableOptions>): void;
         applicableRefactorAvailableAtMarker(markerName: string): void;
         codeFixDiagnosticsAvailableAtMarkers(markerNames: string[], diagnosticCode?: number): void;
         applicableRefactorAvailableForRange(): void;
@@ -200,7 +200,7 @@ declare namespace FourSlashInterface {
         assertHasRanges(ranges: Range[]): void;
         caretAtMarker(markerName?: string): void;
         completions(...options: {
-            readonly marker?: ArrayOrSingle<string>,
+            readonly marker?: ArrayOrSingle<string | Marker>,
             readonly isNewIdentifierLocation?: boolean;
             readonly exact?: ArrayOrSingle<ExpectedCompletionEntry>;
             readonly includes?: ArrayOrSingle<ExpectedCompletionEntry>;
@@ -604,6 +604,12 @@ declare namespace FourSlashInterface {
         triggerCharacter?: string,
     }
 
+    export interface VerifyCodeFixAvailableOptions {
+        readonly description: string;
+        readonly actions?: ReadonlyArray<{ readonly type: string, readonly data: {} }>;
+        readonly commands?: ReadonlyArray<{}?;
+    }
+
     interface VerifyNavigateToOptions {
         readonly pattern: string;
         readonly fileName?: string;

tests/cases/fourslash/genericFunctionSignatureHelp3.ts

@@ -17,10 +17,10 @@
 ////foo7(1, <string>(/*7*/   // signature help shows y as T
 
 verify.signatureHelp(
-    { marker: "1", text: "foo1<T>(x: number, callback: (y1: T) => number): void" },
+    { marker: "1", text: "foo1(x: number, callback: (y1: {}) => number): void" },
     // TODO: GH#23631
     // { marker: "2", text: "foo2(x: number, callback: (y2: {}) => number): void" },
-    { marker: "3", text: "foo3<T>(x: number, callback: (y3: T) => number): void" },
+    { marker: "3", text: "foo3(x: number, callback: (y3: {}) => number): void" },
     // TODO: GH#23631
     // { marker: "4", text: "foo4(x: number, callback: (y4: string) => number): void" },
     { marker: "5", text: "foo5(x: number, callback: (y5: string) => number): void" },
@@ -31,4 +31,4 @@ goTo.marker('6');
 // verify.signatureHelp({ text: "foo6(x: number, callback: (y6: {}) => number): void" });
 edit.insert('string>(null,null);'); // need to make this line parse so we can get reasonable LS answers to later tests
 
-verify.signatureHelp({ marker: "7", text: "foo7<T>(x: number, callback: (y7: T) => number): void" });
+verify.signatureHelp({ marker: "7", text: "foo7(x: number, callback: (y7: {}) => number): void" });

tests/cases/fourslash/genericFunctionSignatureHelp3MultiFile.ts

@@ -24,9 +24,9 @@
 ////foo7(1, <string>(/*7*/   // signature help shows y as T
 
 verify.signatureHelp(
-    { marker: "1", text: "foo1<T>(x: number, callback: (y1: T) => number): void" },
-    { marker: "2", text: "foo2<T>(x: number, callback: (y2: T) => number): void" },
-    { marker: "3", text: "foo3<T>(x: number, callback: (y3: T) => number): void" },
+    { marker: "1", text: "foo1(x: number, callback: (y1: {}) => number): void" },
+    { marker: "2", text: "foo2(x: number, callback: (y2: {}) => number): void" },
+    { marker: "3", text: "foo3(x: number, callback: (y3: {}) => number): void" },
     { marker: "4", text: "foo4(x: number, callback: (y4: string) => number): void" },
     { marker: "5", text: "foo5(x: number, callback: (y5: string) => number): void" },
 );
@@ -35,4 +35,4 @@ goTo.marker('6');
 verify.signatureHelp({ text: "foo6(x: number, callback: (y6: {}) => number): void" });
 edit.insert('string>(null,null);'); // need to make this line parse so we can get reasonable LS answers to later tests
 
-verify.signatureHelp({ marker: "7", text: "foo7<T>(x: number, callback: (y7: T) => number): void" })
+verify.signatureHelp({ marker: "7", text: "foo7(x: number, callback: (y7: {}) => number): void" })

tests/cases/fourslash/jsDocFunctionSignatures10.ts

@@ -12,4 +12,4 @@
 ////fo/**/o()
 
 goTo.marker();
-verify.quickInfoIs("function foo<T>(x: T): void", "Do some foo things");
+verify.quickInfoIs("function foo<any>(x: any): void", "Do some foo things");

tests/cases/fourslash/jsdocReturnsTag.ts

@@ -14,7 +14,7 @@
 
 verify.signatureHelp({
     marker: "",
-    text: "find<T>(l: T[], x: T): T",
+    text: "find(l: any[], x: any): any",
     docComment: "Find an item",
     tags: [
         // TODO: GH#24130 (see PR #24600's commits for potential fix)

tests/cases/fourslash/quickInfoCanBeTruncated.ts

@@ -509,7 +509,7 @@
 //// function f<T extends A>(s: T, x: Exclude<A, T>, y: string) {}
 //// f("_499", /*3*/);
 //// type Decomposed/*4*/ = {[K in A]: Foo[K]}
-//// type LongTuple/*5*/ = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17.18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70]; 
+//// type LongTuple/*5*/ = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17.18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70];
 //// type DeeplyMapped/*6*/ = {[K in keyof Foo]: {[K2 in keyof Foo]: [K, K2, Foo[K], Foo[K2]]}}
 
 goTo.marker("1");
@@ -519,7 +519,7 @@ verify.quickInfoIs(`type Less = "_1" | "_2" | "_3" | "_4" | "_5" | "_6" | "_7" |
 goTo.marker("3");
 verify.signatureHelp({
     marker: "3",
-    text: `f<T extends "_0" | "_1" | "_2" | "_3" | "_4" | "_5" | "_6" | "_7" | "_8" | "_9" | "_10" | "_11" | "_12" | "_13" | "_14" | "_15" | "_16" | "_17" | "_18" | "_19" | "_20" | "_21" | "_22" | "_23" | "_24" | ... 474 more ... | "_499">(s: T, x: Exclude<"_0", T> | Exclude<"_1", T> | Exclude<"_2", T> | Exclude<"_3", T> | Exclude<"_4", T> | Exclude<"_5", T> | Exclude<"_6", T> | Exclude<"_7", T> | Exclude<...> | ... 490 more ... | Exclude<...>, y: string): void`
+    text: `f(s: "_0" | "_1" | "_2" | "_3" | "_4" | "_5" | "_6" | "_7" | "_8" | "_9" | "_10" | "_11" | "_12" | "_13" | "_14" | "_15" | "_16" | "_17" | "_18" | "_19" | "_20" | "_21" | "_22" | "_23" | "_24" | ... 474 more ... | "_499", x: never, y: string): void`
 });
 goTo.marker("4");
 verify.quickInfoIs(`type Decomposed = {

tests/cases/fourslash/quickInfo_errorSignatureFillsInTypeParameter.ts

@@ -0,0 +1,6 @@
+/// <reference path='fourslash.ts'/>
+
+////declare function f<T>(x: number): T;
+////const x/**/ = f();
+
+verify.quickInfoAt("", "const x: {}");

tests/cases/fourslash/signatureHelpExplicitTypeArguments.ts

@@ -8,7 +8,7 @@
 
 verify.signatureHelp(
     { marker: "1", text: "f(x: number, y: string): number" },
-    { marker: "2", text: "f<T = boolean, U = string>(x: T, y: U): T" },
+    { marker: "2", text: "f(x: {}, y: {}): {}" },
     // too few -- fill in rest with {}
     { marker: "3", text: "f(x: number, y: {}): number" },
     // too many -- ignore extra type arguments

tests/cases/fourslash/signatureHelpOnTypePredicates.ts

@@ -9,6 +9,6 @@
 
 verify.signatureHelp(
     { marker: "1", text: "f1(a: any): a is number" },
-    { marker: "2", text: "f2<T>(a: any): a is T" },
+    { marker: "2", text: "f2(a: any): a is {}" },
     { marker: "3", text: "f3(a: any, ...b: any[]): a is number", isVariadic: true },
 )

tests/cases/fourslash/signatureHelpWithTriggers02.ts

@@ -9,7 +9,7 @@ goTo.marker("1");
 
 edit.insert("(");
 verify.signatureHelp({
-    text: "bar<U>(x: U, y: U): U",
+    text: "bar(x: {}, y: {}): {}",
     triggerReason: {
         kind: "characterTyped",
         triggerCharacter: "(",