/*
 * Copyright (c) 2022-2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


function foo(a: number, b?: string): number;
function foo(a: string | number, b: string, c: number): number;
function foo(a: string | number, b?: string, c?: number) {
    return 12;
}

var a: string = foo(2);
/* @@? 23:5 Error TypeError: Type 'number' is not assignable to type 'string'.  */