茉莉花单元测试可观察的订阅不会触发 [英] Jasmine unit testing observable subscribe does not trigger

问题描述

我正在将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，但是我的订阅在单元测试期间不会触发.当我使用茉莉花的完成功能时，这会导致我的单元测试失败. 我想使此单元测试成功.

I'm using Angular 5 with Jasmine and Karma. I'm trying to test whether a certain function works but my subscribe doesn't trigger during unit testing. this causes my unit test to fail as I'm using the done function of jasmine. I want to make this unit test succeed.

我将超时间隔设置为20秒，以查看是否花了一段时间(不应该这样).

I've set the timeout interval to 20 seconds to see if it just took a while (which it shouldn't).

我也尝试过使用async和fakeasync，但是它不会触发.我可以进行订阅触发吗?

I've tried to use async and fakeasync as well, but it doesn't trigger. Is it possible for me to make the subscription to trigger?

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();
    });
  });
});

这是与Basavaraj Bhusani一起使用的代码

this is the code that worked with thanks to Basavaraj Bhusani

      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();
  });
});

推荐答案

如果service.ItemsToFilterBy$是Subject<any>()，而不是BehaviorSubject或ReplaySubject，请在规范开始时订阅service.ItemsToFilterBy$.在此处阅读.

If service.ItemsToFilterBy$ is Subject<any>(), not BehaviorSubject or ReplaySubject, subscribe to service.ItemsToFilterBy$ in the beginning of your spec. Read here.

监视方法时，请按jasmine使用callThrough()方法. spyOn(service.ItemsToFilterBy$, 'subscribe')

Use the callThrough() method by jasmine when you spy on a method. spyOn(service.ItemsToFilterBy$, 'subscribe')

即

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

在此处 https://jasmine.github.io/2.0/introduction了解有关callThrough的信息. .html

Read about callThrough here https://jasmine.github.io/2.0/introduction.html

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