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 Base {
17    public length() : int {
18        return 1;
19    }
20}
21
22class Derived extends Base{
23    public length() : int {
24        return 2;
25    }
26}
27
28
29function testLength<C extends Base>(data: C | undefined): int {
30    let len = data?.length() ?? 0;
31    return len;
32}
33
34function main() : void {
35    let foo1 = new Base();
36    let foo2 = new Derived();
37
38    assert testLength(foo1) == 1;
39    assert testLength(foo2) == 2;
40}