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Map both declared properties and string index signatures

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This commit is contained in:
Anders Hejlsberg
2016-12-14 14:59:00 -08:00
parent 2e97cffe61
commit f58e1a2b17
1 changed files with 20 additions and 9 deletions
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29
src/compiler/checker.ts
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@@ -4536,15 +4536,27 @@ namespace ts {
const typeParameter = getTypeParameterFromMappedType(type);
const constraintType = getConstraintTypeFromMappedType(type);
const templateType = getTemplateTypeFromMappedType(type);
const modifiersType = getModifiersTypeFromMappedType(type);
const modifiersType = getApparentType(getModifiersTypeFromMappedType(type));
const templateReadonly = !!type.declaration.readonlyToken;
const templateOptional = !!type.declaration.questionToken;
// First, if the constraint type is a type parameter, obtain the base constraint. Then,
// if the key type is a 'keyof X', obtain 'keyof C' where C is the base constraint of X.
// Finally, iterate over the constituents of the resulting iteration type.
const keyType = constraintType.flags & TypeFlags.TypeVariable ? getApparentType(constraintType) : constraintType;
const iterationType = keyType.flags & TypeFlags.Index ? getIndexType(getApparentType((<IndexType>keyType).type)) : keyType;
forEachType(iterationType, t => {
if (type.declaration.typeParameter.constraint.kind === SyntaxKind.TypeOperator) {
// We have a { [P in keyof T]: X }
forEachType(getLiteralTypeFromPropertyNames(modifiersType), addMemberForKeyType);
if (getIndexInfoOfType(modifiersType, IndexKind.String)) {
addMemberForKeyType(stringType);
}
}
else {
// First, if the constraint type is a type parameter, obtain the base constraint. Then,
// if the key type is a 'keyof X', obtain 'keyof C' where C is the base constraint of X.
// Finally, iterate over the constituents of the resulting iteration type.
const keyType = constraintType.flags & TypeFlags.TypeVariable ? getApparentType(constraintType) : constraintType;
const iterationType = keyType.flags & TypeFlags.Index ? getIndexType(getApparentType((<IndexType>keyType).type)) : keyType;
forEachType(iterationType, addMemberForKeyType);
}
setStructuredTypeMembers(type, members, emptyArray, emptyArray, stringIndexInfo, undefined);
function addMemberForKeyType(t: Type) {
// Create a mapper from T to the current iteration type constituent. Then, if the
// mapped type is itself an instantiated type, combine the iteration mapper with the
// instantiation mapper.
@@ -4565,8 +4577,7 @@ namespace ts {
else if (t.flags & TypeFlags.String) {
stringIndexInfo = createIndexInfo(propType, templateReadonly);
}
});
setStructuredTypeMembers(type, members, emptyArray, emptyArray, stringIndexInfo, undefined);
}
}
function getTypeParameterFromMappedType(type: MappedType) {