maxmustermann/TypeScript
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Make generic mapped type relationship more inclusive

Browse source
This commit is contained in:
Anders Hejlsberg 2017-10-29 16:49:28 -07:00
parent 7798f69558
commit b3a24322d3
1 changed files with 18 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

38
src/compiler/checker.ts
View file

@ -9454,32 +9454,30 @@ namespace ts {
}
}
}
else if (isGenericMappedType(target) && !isGenericMappedType(source) && getConstraintTypeFromMappedType(<MappedType>target) === getIndexType(source)) {
// A source type T is related to a target type { [P in keyof T]: X } if T[P] is related to X.
const indexedAccessType = getIndexedAccessType(source, getTypeParameterFromMappedType(<MappedType>target));
const templateType = getTemplateTypeFromMappedType(<MappedType>target);
if (result = isRelatedTo(indexedAccessType, templateType, reportErrors)) {
errorInfo = saveErrorInfo;
return result;
}
}
if (source.flags & TypeFlags.TypeParameter) {
// A source type T is related to a target type { [P in keyof T]: X } if T[P] is related to X.
if (getObjectFlags(target) & ObjectFlags.Mapped && getConstraintTypeFromMappedType(<MappedType>target) === getIndexType(source)) {
const indexedAccessType = getIndexedAccessType(source, getTypeParameterFromMappedType(<MappedType>target));
const templateType = getTemplateTypeFromMappedType(<MappedType>target);
if (result = isRelatedTo(indexedAccessType, templateType, reportErrors)) {
let constraint = getConstraintOfTypeParameter(<TypeParameter>source);
// A type parameter with no constraint is not related to the non-primitive object type.
if (constraint || !(target.flags & TypeFlags.NonPrimitive)) {
if (!constraint || constraint.flags & TypeFlags.Any) {
constraint = emptyObjectType;
}
// Report constraint errors only if the constraint is not the empty object type
const reportConstraintErrors = reportErrors && constraint !== emptyObjectType;
if (result = isRelatedTo(constraint, target, reportConstraintErrors)) {
errorInfo = saveErrorInfo;
return result;
}
}
else {
let constraint = getConstraintOfTypeParameter(<TypeParameter>source);
// A type parameter with no constraint is not related to the non-primitive object type.
if (constraint || !(target.flags & TypeFlags.NonPrimitive)) {
if (!constraint || constraint.flags & TypeFlags.Any) {
constraint = emptyObjectType;
}
// Report constraint errors only if the constraint is not the empty object type
const reportConstraintErrors = reportErrors && constraint !== emptyObjectType;
if (result = isRelatedTo(constraint, target, reportConstraintErrors)) {
errorInfo = saveErrorInfo;
return result;
}
}
}
}
else if (source.flags & TypeFlags.IndexedAccess) {
// A type S[K] is related to a type T if A[K] is related to T, where K is string-like and