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 */
15class C {
16    once : boolean = true
17}
18
19class A {
20    global : boolean | undefined = undefined
21    current : C | undefined
22
23    foo () {
24        if (this.global == undefined) this.global = this.current?.once != true
25    }
26}
27
28function main(): void {
29    let a = new A()
30    a.foo()
31    assert(a.global == true)
32
33    a.global = undefined
34    a.current = new C()
35    a.foo()
36    assert(a.global == false)
37}
38