Jasmine 等待 Observable 訂閱

Question

我有以下課程：

@Injectable()
export class MyService {
  private subscriptions: { [key: string]: Subscription } = {};

  constructor(private otherService: OtherService) {
  }

  public launchTimer(order: any): void {
    this.subscriptions[order.id] = timer(500, 300000).subscribe(
      () => {
        this.otherService.notify();
      },
    );
  }
}

我想編寫一個單元測試，它斷言在調用 launchTimer()時，將調用OtherService的notify方法。 關於這一點的棘手之處在於，對計時器observable 的訂閱是直接在方法中完成的，這意味着我不能直接在單元測試中進行訂閱來進行斷言。
到目前為止，我想出的是以下測試失敗，因為斷言是在訂閱之前完成的：

class OtherServiceMock {
  public notify(): void {}
}

describe('MyService', () => {
  let otherService: OtherServiceMock;
  let myService: MyService;
  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        { provide: OtherService, useClass: OtherServiceMock },
      ],
    });
    otherService = TestBed.get(OtherService);
    myService = TestBed.get(MyService);
  });

  it('launchTimer should call notify', () => {
    spyOn(otherService, 'notify');
    myService.launchTimer();
    expect(otherService.notify).toHaveBeenCalled();
  });
});

我試圖用async包裝函數，我還使用了帶刻度的fakeAsync但似乎沒有任何效果。 任何想法如何在做出斷言之前等待訂閱？

Answer 1

使用間隔和計時器測試 observables 可能很棘手，但試試這個，如果這不起作用，我也可以用不同的方式來做。

class OtherServiceMock {
  public notify(): void {}
}

describe('MyService', () => {
  let otherService: OtherServiceMock;
  let myService: MyService;
  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        { provide: OtherService, useClass: OtherServiceMock },
      ],
    });
    otherService = TestBed.get(OtherService);
    myService = TestBed.get(MyService);
  });

  it('launchTimer should call notify', fakeAsync(() => {
    // you're going to have to make `subscriptions` public for this to work !!
    spyOn(otherService, 'notify'); // don't need to callThrough to see if it was called or not
    myService.launchTimer({id: 1});
    tick(501);
    expect(otherService.notify).toHaveBeenCalled();
    myService.subscriptions['1'].unsubscribe(); // kill the timer subscription
  }));
});

==================== 編輯 ============================ ========

您要么必須公開subscriptions要么提供一種公共方式來取消訂閱該對象中的訂閱。