1/* 2 * Copyright (c) 2023 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 description: > 17 typescript 2.3 adds support for declaring defaults for generic type parameters. 18 default types for a type parameter must satisfy the constraint for the type parameter, if it exists. 19 module: ESNext 20 isCurrent: true 21 ---*/ 22 23 24import { Assert } from '../../../suite/assert.js' 25 26interface Length { 27 length: number; 28} 29type STRS = string | string[] 30function fun3<T extends Length = STRS>(s: T) { 31 return s.length; 32} 33Assert.equal(fun3<STRS>("ABC"), 3); 34Assert.equal(fun3([1, 2, 3, 4]), 4); 35