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 A {
17  protected count: int;
18  getCount(): int {
19    return this.count
20  }
21}
22
23class B extends A {
24  increment(): void {
25    this.count++;
26  }
27}
28
29class C extends A {
30}
31
32function main(): void {
33  let b = new B();
34  let c = new C();
35  b.increment();
36  let a = b ?? c;
37  a.increment();
38}
39
40/* @@? 37:3 Error TypeError: Member type must be the same for all union objects.  */
41/* @@? 37:5 Error TypeError: Property 'increment' does not exist on type 'C'  */
42