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角度6单位测试,设置超时无效

angular-unit-test angular6 angular5 unit-testing angular

Varun · 技术社区 · 6 年前

我有一个组件,在ngoninit函数内部有一个setTimeout函数。为了编写单元测试用例,我使用Tick和FakeAsync快速转发设置超时。但是,它不会被执行,而这反过来又不会调用其他函数closeAlert()。

组件代码:

export class BannerComponent implements OnInit {

  @Input()errorData: any;

  @Input()callback: any;

  @Input()autoHide: boolean;

  constructor() { }

  ngOnInit() {

    if (this.autoHide) {
      setTimeout
        (() => {
          this.closeAlert();
        }, 500);
    }
  }

  closeAlert() {
    this.errorData = null;
    if (this.callback) {
      this.callback();
    }
  };
}

规格文件:

describe('BannerComponent', () => {
  let component: BannerComponent;
  let fixture: ComponentFixture<BannerComponent>;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ BannerComponent ]
    })
    .compileComponents();
  }));

  beforeEach(async() => {
    fixture = TestBed.createComponent(BannerComponent);
    component = fixture.componentInstance;
    component.ngOnInit();
    fixture.detectChanges();
  });

  it("banner should hide after 500ms", fakeAsync(() => {
    component.errorData = {
      _statusMessage: "New alert banner",
      _statusCode: '200',
    };
    component.callback = null;;
    component.autoHide = true;

    tick(600);
    fixture.detectChanges()

    fixture.whenStable().then(() => {
      let banner = fixture.debugElement.query(By.css('.success'));
      expect(banner).toBe(null)
    })
  }));

});

HTML代码:

<div class="success">
    <p>{{errorData._statusMessage}}</p>
</div>

1 回复 | 直到 6 年前

dmcgrandle 6 年前

我在代码中看到了一些问题。

你们两个都打 component.ngOnInit() 和 fixture.detectChanges() (也将称为ngoninit)在中设置有效数据之前 component.errorData .
我不清楚你为什么期待 banner 显示的HTML为空。因此我把测试改为看 component.closeAlert() 被召唤,如果 组件错误数据 已经重置为空,因为这似乎是您真正想要测试的。为了测试我所监视的 组件。CloseAlert()) .
我设置了刻度以精确显示呼叫的时间 组件。CloseAlert()) 通过测试之后 tick(499) ,然后再打一个勾…

工作 StackBlitz .

代码:

beforeEach(async(() => { // slight correction of incorrect async wrapper ...
  fixture = TestBed.createComponent(BannerComponent);
  component = fixture.componentInstance;
  // component.ngOnInit(); // <-- don't call this here, the data isn't set up yet ...
  // fixture.detectChanges(); // ditto
}));

it("banner should hide after 500ms", fakeAsync(() => {
  spyOn(component, 'closeAlert').and.callThrough(); // set up a spy so we can test later
  component.errorData = {
    _statusMessage: "New alert banner",
    _statusCode: '200',
  };
  component.callback = null;;
  component.autoHide = true;

  fixture.detectChanges(); // <-- this will execute ngOnInit()
  expect(component.errorData).not.toBeNull(); // <-- after ngOnInit, still NOT null
  expect(component.closeAlert).not.toHaveBeenCalled();
  tick(499); // <-- now let 499ms pass ...
  expect(component.errorData).not.toBeNull(); // <-- after all that "fake" time, still NOT null
  expect(component.closeAlert).not.toHaveBeenCalled();
  tick(1); // <-- now tick for just 1 more millisecond ...
  expect(component.errorData).toBeNull(); // <-- now this has become NULL
  expect(component.closeAlert).toHaveBeenCalled(); // <-- and the method was called
  // fixture.whenStable().then(() => {
  //   let banner = fixture.debugElement.query(By.css('.success'));
  //   expect(banner).toBe(null)
  // });
}));

希望这有帮助!