1/* 2 * Copyright (c) 2023-2025 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 16type funcType = () => String; 17 18function getMelon(): String { return "melon" } 19 20function dummy(): funcType | null { 21 return (() => { return "peach"; }) as funcType; // #15577 22} 23 24function foo(a: funcType | null) { 25 let fruit: String = a?.() ?? "apple"; 26 27 let getPeach: funcType | null = dummy(); 28 fruit = getPeach?.() ?? "banana"; 29 assertEQ(fruit, "peach") 30 31 fruit = getMelon() ?? "strawberry"; 32 assertEQ(fruit, "melon") 33 34 let test = false; 35 try { 36 fruit = a!(); 37 } catch (e: NullPointerError) { 38 test = true; 39 } 40 41 assertEQ(test, true) 42} 43 44function main(): void { 45 let getFruit = null; 46 foo(getFruit); 47 48 let getPeach: funcType | null = dummy(); 49 let b = getPeach?.(); 50 assertEQ(b, "peach") 51} 52