单独运行但未同时运行时测试通过

Question

我有一个组件，我为此编写了两个测试用例。两个测试用例都使用setTimeout。我注意到如果我一起运行测试用例（在单个describe中运行，则测试用例会失败，但是如果将它们放在单独的describe中，则测试用例会通过。为什么？这两个测试用例是

fit('should show dialog when message from DialogBoxService is received', () => {
      let dialogBoxService: MockDialogBoxService = TestBed.get(DialogBoxService);

      let dialogServiceContext = new DialogServiceContext(ComponentAndServiceID.QuestionDetailComponent, new QuestionDetailAdditionalInfo())
      /*
      At startup, there is a delay between creation of AppComponent and subscription to DialogService, I have added the test logic in setTimeout to give time for AppComponent to get created and also subscribe.
       */
      setTimeout(() => {
        spyOn(component, 'showDialog');
        dialogBoxService.emitDialogMessage(dialogServiceContext);
        expect(component.showDialog).toHaveBeenCalledWith(dialogServiceContext);
      }, 1000);
    });

    fit('should handle message from AuthGuard service', () => {
      let mockAuthGuard: MockAuthGuard = TestBed.get(AuthGuard);
      spyOn(component, 'handleAuthGuardContextMessage');
      let authGuardContext = new AuthGuardContext('You must sign in first', new AuthGuardAdditionalInfo());
      setTimeout(() => {
        mockAuthGuard.canActivate();
        expect(component.handleAuthGuardContextMessage).toHaveBeenCalledWith(authGuardContext);
      }, 1000);
    });

我怀疑，问题与以下事实有关：两个测试用例都在1000毫秒后运行它们的expect，而一个可能覆盖了其他情况，但是我不确定，因为我不知道{{ 1}}安排其他jasmine