1/* 2 * Copyright (c) 2024 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16class C {} 17 18function foo(arg?: number): C | undefined { 19 if (arg == 5) return new C(); 20 return arg == 3 ? undefined : new C(); 21} 22 23function main() { 24 assert(foo(5) instanceof C); 25 assert(foo(3) == undefined); 26 assert(foo(undefined) instanceof C); 27} 28