1/* 2 * Copyright (c) 2022-2025 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 16/*--- 17 desc: 7.19 Nullish-Coalescing Expression 18 name: issue14609_02 19 tags: 20 ---*/ 21 22class A<T> { 23 public parent: A<T> 24 data: T 25 constructor(data: T) { 26 this.data = data 27 } 28 foo() : A<T> { 29 return this.parent ?? this 30 } 31} 32 33function main(): void { 34 let a = new A<string>("hello") 35 let aa = a.foo() 36 let b = new A<null>(null) 37 let bb = b.foo() 38 assertTrue( aa instanceof A) 39 assertTrue( bb instanceof A) 40}