我正在写一个角度2单位测试.我有一个@ViewChild子组件,我需要在组件初始化后识别.在这种情况下,这是一个来自ng2-bootstrap库的Timepicker组件,虽然具体细节不重要.在检测到Changes()之后,子组件实例仍然未定义.
伪代码:
@Component({ template: ` <form> <timepicker #timepickerChild [(ngModel)]="myDate"> </timepicker> </form> ` }) export class ExampleComponent implements OnInit { @ViewChild('timepickerChild') timepickerChild: TimepickerComponent; public myDate = new Date(); } // Spec describe('Example Test',() => { let exampleComponent: ExampleComponent; let fixture: ComponentFixture<ExampleComponent>; beforeEach(() => { TestBed.configureTestingModel({ // ... whatever needs to be configured }); fixture = TestBed.createComponent(ExampleComponent); }); it('should recognize a timepicker'. async(() => { fixture.detectChanges(); const timepickerChild: Timepicker = fixture.componentInstance.timepickerChild; console.log('timepickerChild',timepickerChild) })); });
伪代码按预期工作,直到您到达控制台日志. timepickerChild未定义.为什么会发生这种情况?
我认为它应该有效也许你忘了在配置中导入一些模块.以下是完整的测试代码:
import { TestBed,ComponentFixture,async } from '@angular/core/testing'; import { Component,DebugElement } from '@angular/core'; import { FormsModule } from '@angular/forms'; import { ExampleComponent } from './test.component'; import { TimepickerModule,TimepickerComponent } from 'ng2-bootstrap/ng2-bootstrap'; describe('Example Test',() => { let exampleComponent: ExampleComponent; let fixture: ComponentFixture<ExampleComponent>; beforeEach(() => { TestBed.configureTestingModule({ imports: [FormsModule,TimepickerModule.forRoot()],declarations: [ ExampleComponent ] }); fixture = TestBed.createComponent(ExampleComponent); }); it('should recognize a timepicker',async(() => { fixture.detectChanges(); const timepickerChild: TimepickerComponent = fixture.componentInstance.timepickerChild; console.log('timepickerChild',timepickerChild); expect(timepickerChild).toBeDefined(); })); });