Only check if the index type should be deferred for intersection types

microsoft · Aug 31, 2022 · 2ba9ff1 · 2ba9ff1
1 parent 00e3926
commit 2ba9ff1
Showing 1 changed file with 1 addition and 4 deletions.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -15903,13 +15903,10 @@ namespace ts {
  }
 
  function distributeIndexOverObjectType(objectType: Type, indexType: Type, writing: boolean) {
- if (shouldDeferIndexType(objectType)) {
- return;
- }
  // (T | U)[K] -> T[K] | U[K] (reading)
  // (T | U)[K] -> T[K] & U[K] (writing)
  // (T & U)[K] -> T[K] & U[K]
- if (objectType.flags & TypeFlags.UnionOrIntersection) {
+ if (objectType.flags & TypeFlags.Union || objectType.flags & TypeFlags.Intersection && !shouldDeferIndexType(objectType)) {
  const types = map((objectType as UnionOrIntersectionType).types, t => getSimplifiedType(getIndexedAccessType(t, indexType), writing));
  return objectType.flags & TypeFlags.Intersection || writing ? getIntersectionType(types) : getUnionType(types);
  }