More closely match previous behavior

microsoft · May 24, 2021 · d45806a · d45806a
1 parent 86f09ae
commit d45806a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -24122,7 +24122,7 @@ namespace ts {
         }
 
         function isGenericTypeWithUnionConstraint(type: Type) {
-            return !!(type.flags & TypeFlags.Instantiable && getBaseConstraintOrType(type).flags & TypeFlags.Union);
+            return !!(type.flags & TypeFlags.Instantiable && getBaseConstraintOrType(type).flags & (TypeFlags.Nullable | TypeFlags.Union));
         }
 
         function containsGenericType(type: Type): boolean {