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Merge pull request #17870 from Microsoft/fix-getConstraintOfIndexedAccess

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Fix getConstraintOfIndexedAccess
This commit is contained in:
Arthur Ozga
2017-08-18 11:32:48 -07:00
committed by GitHub
parent ade3b565ae a187b17e97
commit 439cdca52f
9 changed files with 334 additions and 8 deletions
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18
src/compiler/checker.ts
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@@ -5911,7 +5911,13 @@ namespace ts {
return transformed;
}
const baseObjectType = getBaseConstraintOfType(type.objectType);
const baseIndexType = getBaseConstraintOfType(type.indexType);
const keepTypeParameterForMappedType = baseObjectType && getObjectFlags(baseObjectType) & ObjectFlags.Mapped && type.indexType.flags & TypeFlags.TypeParameter;
const baseIndexType = !keepTypeParameterForMappedType && getBaseConstraintOfType(type.indexType);
if (baseObjectType && baseIndexType === stringType && !getIndexInfoOfType(baseObjectType, IndexKind.String)) {
// getIndexedAccessType returns `any` for X[string] where X doesn't have an index signature.
// instead, return undefined so that the indexed access check fails
return undefined;
}
return baseObjectType || baseIndexType ? getIndexedAccessType(baseObjectType || type.objectType, baseIndexType || type.indexType) : undefined;
}
@@ -5961,8 +5967,9 @@ namespace ts {
function computeBaseConstraint(t: Type): Type {
if (t.flags & TypeFlags.TypeParameter) {
const constraint = getConstraintFromTypeParameter(<TypeParameter>t);
return (<TypeParameter>t).isThisType ? constraint :
constraint ? getBaseConstraint(constraint) : undefined;
return (t as TypeParameter).isThisType || !constraint ?
constraint :
getBaseConstraint(constraint);
}
if (t.flags & TypeFlags.UnionOrIntersection) {
const types = (<UnionOrIntersectionType>t).types;
@@ -5990,9 +5997,6 @@ namespace ts {
const baseIndexedAccess = baseObjectType && baseIndexType ? getIndexedAccessType(baseObjectType, baseIndexType) : undefined;
return baseIndexedAccess && baseIndexedAccess !== unknownType ? getBaseConstraint(baseIndexedAccess) : undefined;
}
if (isGenericMappedType(t)) {
return emptyObjectType;
}
return t;
}
}
@@ -9289,7 +9293,7 @@ namespace ts {
}
else if (target.flags & TypeFlags.IndexedAccess) {
// A type S is related to a type T[K] if S is related to A[K], where K is string-like and
// A is the apparent type of S.
// A is the apparent type of T.
const constraint = getConstraintOfType(<IndexedAccessType>target);
if (constraint) {
if (result = isRelatedTo(source, constraint, reportErrors)) {

2
src/compiler/core.ts
View File

@@ -718,7 +718,7 @@ namespace ts {
export function sum<T extends Record<K, number>, K extends string>(array: T[], prop: K): number {
let result = 0;
for (const v of array) {
// Note: we need the following type assertion because of GH #17069
// TODO: Remove the following type assertion once the fix for #17069 is merged
result += v[prop] as number;
}
return result;