diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts index b18c39c47db..042848f86cd 100644 --- a/src/compiler/checker.ts +++ b/src/compiler/checker.ts @@ -3256,7 +3256,9 @@ namespace ts { } function resolveTupleTypeMembers(type: TupleType) { - let arrayType = resolveStructuredTypeMembers(createArrayType(getUnionType(type.elementTypes, /*noSubtypeReduction*/ true))); + let arrayElementType = getUnionType(type.elementTypes, /*noSubtypeReduction*/ true); + // Make the tuple type itself the 'this' type by including an extra type argument + let arrayType = resolveStructuredTypeMembers(createTypeFromGenericGlobalType(globalArrayType, [arrayElementType, type])); let members = createTupleTypeMemberSymbols(type.elementTypes); addInheritedMembers(members, arrayType.properties); setObjectTypeMembers(type, members, arrayType.callSignatures, arrayType.constructSignatures, arrayType.stringIndexType, arrayType.numberIndexType); @@ -4159,20 +4161,20 @@ namespace ts { /** * Instantiates a global type that is generic with some element type, and returns that instantiation. */ - function createTypeFromGenericGlobalType(genericGlobalType: GenericType, elementType: Type): Type { - return genericGlobalType !== emptyGenericType ? createTypeReference(genericGlobalType, [elementType]) : emptyObjectType; + function createTypeFromGenericGlobalType(genericGlobalType: GenericType, typeArguments: Type[]): Type { + return genericGlobalType !== emptyGenericType ? createTypeReference(genericGlobalType, typeArguments) : emptyObjectType; } function createIterableType(elementType: Type): Type { - return createTypeFromGenericGlobalType(globalIterableType, elementType); + return createTypeFromGenericGlobalType(globalIterableType, [elementType]); } function createIterableIteratorType(elementType: Type): Type { - return createTypeFromGenericGlobalType(globalIterableIteratorType, elementType); + return createTypeFromGenericGlobalType(globalIterableIteratorType, [elementType]); } function createArrayType(elementType: Type): Type { - return createTypeFromGenericGlobalType(globalArrayType, elementType); + return createTypeFromGenericGlobalType(globalArrayType, [elementType]); } function getTypeFromArrayTypeNode(node: ArrayTypeNode): Type {