我正在 Jasmine 单元测试一个使用 Observables 的角度组件。我的组件有我正在测试的生命周期挂钩：

ngOnInit() {
  this.dataService.getCellOEE(this.cell).subscribe(value => this.updateChart(value));
}

我有一个测试可以确保 getCellOEE 已被调用，但现在我想检查当可观察值解析为新值时是否调用 updateChart。这是我到目前为止所拥有的：

let fakeCellService = {
  getCellOEE: function (value): Observable<Array<IOee>> {
    return Observable.of([{ time: moment(), val: 67 }, { time: moment(), val: 78 }]);
  }
};

describe('Oee24Component', () => {
  let component: Oee24Component;
  let service: CellService;
  let injector: Injector;
  let fixture: ComponentFixture<Oee24Component>;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [Oee24Component],
      providers: [{ provide: CellService, useValue: fakeCellService }]
    })
      .compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(Oee24Component);
    component = fixture.componentInstance;
    injector = getTestBed();
    service = injector.get(CellService)
    fixture.detectChanges();
    spyOn(service, 'getCellOEE').and.returnValue({ subscribe: () => { } });
    spyOn(component, 'updateChart');
  });

  it('should get cell oee on init', () => {
    component.ngOnInit();
    expect(service.getCellOEE).toHaveBeenCalled();
  });

  it('should update chart on new data', () => {
    component.ngOnInit();
    expect(component.updateChart).toHaveBeenCalled();
  });
});

但是，我收到错误：

chrome 56.0.2924 (Windows 10 0.0.0) Oee24Component 应更新新数据图表失败

预期已调用间谍 updateChart。

据推测，这是一个时间问题，因为在测试检查时可观察到的问题不一定得到解决？如果是这种情况，我该如何正确设置？

Update:

这是我的组件：

@Component({
  selector: 'app-oee24',
  templateUrl: './oee24.component.html',
  styleUrls: ['./oee24.component.css']
})
export class Oee24Component implements OnInit {
  public barChartData: any[] = [{ data: [], label: 'OEE' }];

  constructor(public dataService: CellService) { }

  ngOnInit() {
    this.dataService.getCellOEE(this.cell).subscribe(value => this.updateChart(value));
  }

  updateChart(data: Array<IOee>) {
    this.barChartData[0].data = data.map(val => val.val);
  }
}
 

你有没有想出解决办法？怎么样使用jasmine-marbles包和complete event?

it('should update chart on new data', () => {
    const obs$ = cold('--a-|');
    spyOn(service, 'getCellOEE').and.returnValue(obs$);
    component.ngOnInit(); 
    obs$.subscribe({
        complete: () => {
            expect(component.updateChart).toHaveBeenCalledWith('a');
        }
    });
});