Jasmine单元测试observable订阅不触发

Question

我将 Angular 5 与 Jasmine 和 Karma 一起使用。我正在尝试测试某个功能是否有效，但我的订阅在单元测试期间没有触发。这导致我的单元测试失败，因为我正在使用 jasmine 的 did 函数。我想让这个单元测试成功。

我已将超时间隔设置为 20 秒，以查看是否只花了一段时间（实际上不应该）。

我也尝试过使用 async 和 fakeasync，但它不会触发。我可以触发订阅吗？

这是我得到的代码：

describe('FilterService', () => {
  let service: FilterService;

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [FilterService]
    });
    service = TestBed.get(FilterService);
    jasmine.DEFAULT_TIMEOUT_INTERVAL = 20000;
  });

  it("SetItemsToFilterByAndApplyFilters should set ItemsToFilterBy and set the InFilter property", (done: DoneFn) => {
    //arrange
    let item1: any = new Organisation();
    item1.Id = 1;
    item1.InFilter = true;
    let item2: any = new Organisation();
    item1.Id = 2;
    item1.InFilter = false;

    let itemNew1: any = new Organisation();
    itemNew1.Id = 1;
    let itemNew2: any = new Organisation();
    itemNew2.Id = 2;

    service.SetItemsToFilterBy([item1, item2]);
    let spy = spyOn(service.ItemsToFilterBy$, 'subscribe');

    //act
    service.SetItemsToFilterByAndApplyFilters([itemNew1, itemNew2]);
    //assert
    service.ItemsToFilterBy$.subscribe(result => {
      let result1 = _.find(result, item => {
        return item.Id == itemNew1.Id;
      });

      let result2 = _.find(result, item => {
        return item.Id == itemNew2.Id;
      });

      expect(result1.InFilter).toBeTruthy();
      expect(result2.InFilter).toBeFalsy();
      done();
    });
  });
});

感谢Basavaraj Bhusani，这是可以使用的代码

      it("SetItemsToFilterByAndApplyFilters should set ItemsToFilterBy and set the InFilter property", (done: DoneFn) => {

    //arrange
    let spy = spyOn(service.ItemsToFilterBy$, 'subscribe').and.callThrough();

    let item1: any = new Organisation();
    item1.Id = 1;
    item1.InFilter = true;
    let item2: any = new Organisation();
    item2.Id = 2;
    item2.InFilter = false;

    let itemNew1: any = new Organisation();
    itemNew1.Id = 1;
    let itemNew2: any = new Organisation();
    itemNew2.Id = 2;

    service.SetItemsToFilterBy([item1, item2]);

    //act
    service.SetItemsToFilterByAndApplyFilters([itemNew1, itemNew2]);

    //assert
    service.ItemsToFilterBy$.subscribe(result => {
      let result1 = _.find(result, item => {
        return item.Id == itemNew1.Id;
      });

      let result2 = _.find(result, item => {
        return item.Id == itemNew2.Id;
      });

      expect(result1.InFilter).toBeTruthy();
      expect(result2.InFilter).toBeFalsy();
      done();
    });
    expect(spy).toHaveBeenCalled();
  });
});

Answer 1

如果service.ItemsToFilterBy$是Subject<any>()、不是BehaviorSubject或，请在规范的开头ReplaySubject订阅。service.ItemsToFilterBy$阅读此处。

当您监视某个方法时， 请使用该callThrough()方法。jasminespyOn(service.ItemsToFilterBy$, 'subscribe')

IE

const spy = spyOn(service.ItemsToFilterBy$, 'subscribe').and.callThrough();

callThrough在这里阅读https://jasmine.github.io/2.0/introduction.html