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}