use recombineUnknownType

microsoft · Dec 17, 2024 · 042aced · 042aced
1 parent 6fdf096
commit 042aced
Showing 1 changed file with 1 addition and 3 deletions.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -29404,11 +29404,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 if (checkDerived) {
                     return filterType(type, t => !isTypeDerivedFrom(t, candidate));
                 }
-                const originalType = type;
                 type = type.flags & TypeFlags.Unknown ? unknownUnionType : type;
                 const trueType = getNarrowedType(type, candidate, /*assumeTrue*/ true, /*checkDerived*/ false);
-                const filtered = filterType(type, t => !isTypeSubsetOf(t, trueType));
-                return originalType.flags & TypeFlags.Unknown && filtered === type ? originalType : filtered;
+                return recombineUnknownType(filterType(type, t => !isTypeSubsetOf(t, trueType)));
             }
             if (type.flags & TypeFlags.AnyOrUnknown) {
                 return candidate;