59 lines
1.7 KiB
TypeScript
59 lines
1.7 KiB
TypeScript
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/**
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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, Input, OnChanges, SimpleChanges} from '@angular/core';
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import {TestBed} from '@angular/core/testing';
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describe('ngOnChanges', () => {
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it('should correctly support updating one Input among many', () => {
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let log: string[] = [];
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@Component({selector: 'child-comp', template: 'child'})
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class ChildComp implements OnChanges {
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@Input() a: number = 0;
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@Input() b: number = 0;
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@Input() c: number = 0;
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ngOnChanges(changes: SimpleChanges) {
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for (let key in changes) {
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const simpleChange = changes[key];
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log.push(key + ': ' + simpleChange.previousValue + ' -> ' + simpleChange.currentValue);
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}
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}
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}
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@Component(
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{selector: 'app-comp', template: '<child-comp [a]="a" [b]="b" [c]="c"></child-comp>'})
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class AppComp {
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a = 0;
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b = 0;
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c = 0;
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}
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TestBed.configureTestingModule({declarations: [AppComp, ChildComp]});
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const fixture = TestBed.createComponent(AppComp);
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fixture.detectChanges();
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const appComp = fixture.componentInstance;
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expect(log).toEqual(['a: undefined -> 0', 'b: undefined -> 0', 'c: undefined -> 0']);
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log.length = 0;
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appComp.a = 1;
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fixture.detectChanges();
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expect(log).toEqual(['a: 0 -> 1']);
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log.length = 0;
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appComp.b = 2;
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fixture.detectChanges();
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expect(log).toEqual(['b: 0 -> 2']);
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log.length = 0;
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appComp.c = 3;
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fixture.detectChanges();
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expect(log).toEqual(['c: 0 -> 3']);
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});
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});
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