53 lines
1.5 KiB
TypeScript
53 lines
1.5 KiB
TypeScript
/**
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* @license
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* Copyright Google Inc. All Rights Reserved.
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*
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* Use of this source code is governed by an MIT-style license that can be
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* found in the LICENSE file at https://angular.io/license
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*/
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import {Component, InjectionToken} from '@angular/core';
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import {TestBed} from '@angular/core/testing';
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describe('component', () => {
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describe('view destruction', () => {
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it('should invoke onDestroy only once when a component is registered as a provider', () => {
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const testToken = new InjectionToken<ParentWithOnDestroy>('testToken');
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let destroyCalls = 0;
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@Component({
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selector: 'comp-with-on-destroy',
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template: '',
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providers: [{provide: testToken, useExisting: ParentWithOnDestroy}]
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})
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class ParentWithOnDestroy {
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ngOnDestroy() { destroyCalls++; }
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}
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@Component({selector: 'child', template: ''})
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class ChildComponent {
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// We need to inject the parent so the provider is instantiated.
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constructor(_parent: ParentWithOnDestroy) {}
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}
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@Component({
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template: `
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<comp-with-on-destroy>
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<child></child>
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</comp-with-on-destroy>
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`
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})
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class App {
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}
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TestBed.configureTestingModule({declarations: [App, ParentWithOnDestroy, ChildComponent]});
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const fixture = TestBed.createComponent(App);
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fixture.detectChanges();
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fixture.destroy();
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expect(destroyCalls).toBe(1, 'Expected `ngOnDestroy` to only be called once.');
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});
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});
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});
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