13af6ab5fSopenharmony_ci/* 23af6ab5fSopenharmony_ci * Copyright (c) 2023-2024 Huawei Device Co., Ltd. 33af6ab5fSopenharmony_ci * Licensed under the Apache License, Version 2.0 (the "License"); 43af6ab5fSopenharmony_ci * you may not use this file except in compliance with the License. 53af6ab5fSopenharmony_ci * You may obtain a copy of the License at 63af6ab5fSopenharmony_ci * 73af6ab5fSopenharmony_ci * http://www.apache.org/licenses/LICENSE-2.0 83af6ab5fSopenharmony_ci * 93af6ab5fSopenharmony_ci * Unless required by applicable law or agreed to in writing, software 103af6ab5fSopenharmony_ci * distributed under the License is distributed on an "AS IS" BASIS, 113af6ab5fSopenharmony_ci * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 123af6ab5fSopenharmony_ci * See the License for the specific language governing permissions and 133af6ab5fSopenharmony_ci * limitations under the License. 143af6ab5fSopenharmony_ci */ 153af6ab5fSopenharmony_ci 163af6ab5fSopenharmony_ciclass Foo { 173af6ab5fSopenharmony_ci foo: number = 0 183af6ab5fSopenharmony_ci common: string = "" 193af6ab5fSopenharmony_ci} 203af6ab5fSopenharmony_ci 213af6ab5fSopenharmony_ciclass Bar { 223af6ab5fSopenharmony_ci bar: number = 0 233af6ab5fSopenharmony_ci common: string = "" 243af6ab5fSopenharmony_ci} 253af6ab5fSopenharmony_ci 263af6ab5fSopenharmony_cifunction isFoo(arg: any): arg is Foo { 273af6ab5fSopenharmony_ci return arg.foo !== undefined 283af6ab5fSopenharmony_ci} 293af6ab5fSopenharmony_ci 303af6ab5fSopenharmony_cifunction doStuff(arg: Foo | Bar) { 313af6ab5fSopenharmony_ci if (isFoo(arg)) { 323af6ab5fSopenharmony_ci console.log(arg.foo) // OK 333af6ab5fSopenharmony_ci console.log(arg.bar) // Compile-time error 343af6ab5fSopenharmony_ci } else { 353af6ab5fSopenharmony_ci console.log(arg.foo) // Compile-time error 363af6ab5fSopenharmony_ci console.log(arg.bar) // OK 373af6ab5fSopenharmony_ci } 383af6ab5fSopenharmony_ci} 393af6ab5fSopenharmony_ci 403af6ab5fSopenharmony_cidoStuff({ foo: 123, common: '123' }) 413af6ab5fSopenharmony_cidoStuff({ bar: 123, common: '123' }) 423af6ab5fSopenharmony_ci 433af6ab5fSopenharmony_ci 443af6ab5fSopenharmony_cifunction isFoo2(arg: Object): boolean { 453af6ab5fSopenharmony_ci return arg instanceof Foo 463af6ab5fSopenharmony_ci} 473af6ab5fSopenharmony_ci 483af6ab5fSopenharmony_cifunction doStuff2(arg: Object): void { 493af6ab5fSopenharmony_ci if (isFoo2(arg)) { 503af6ab5fSopenharmony_ci let fooArg = arg as Foo 513af6ab5fSopenharmony_ci console.log(fooArg.foo) // OK 523af6ab5fSopenharmony_ci console.log(arg.bar) // Compile-time error 533af6ab5fSopenharmony_ci } else { 543af6ab5fSopenharmony_ci let barArg = arg as Bar 553af6ab5fSopenharmony_ci console.log(arg.foo) // Compile-time error 563af6ab5fSopenharmony_ci console.log(barArg.bar) // OK 573af6ab5fSopenharmony_ci } 583af6ab5fSopenharmony_ci} 593af6ab5fSopenharmony_ci 603af6ab5fSopenharmony_cifunction main(): void { 613af6ab5fSopenharmony_ci doStuff2(new Foo()) 623af6ab5fSopenharmony_ci doStuff2(new Bar()) 633af6ab5fSopenharmony_ci}