单元测试使用打字稿，业力和茉莉花的RxJS Observable.timer

Question

嗨我对Angular2，Karma和Jasmine比较陌生。目前我使用角2 RC4茉莉花2.4.x的 我有一个角2服务，定期调用像这样的http服务：

getDataFromDb() { return Observable.timer(0, 2000).flatMap(() => { 
     return this.http.get(this.backendUrl) 
      .map(this.extractData) 
      .catch(this.handleError); 
    }); 
} 

现在我要测试的功能。出于测试目的，我已经做只是测试的“http.get”上没有Observable.timer一个单独的函数：

const mockHttpProvider = { 
    deps: [MockBackend, BaseRequestOptions], 
    useFactory: (backend: MockBackend, defaultOptions: BaseRequestOptions) => { 
     return new Http(backend, defaultOptions); 
    } 
} 

describe('data.service test suite',() => { 
    var dataFromDbExpected: any; 

    beforeEachProviders(() => { 
     return [ 
      DataService, 
      MockBackend, 
      BaseRequestOptions, 
      provide(Http, mockHttpProvider), 
     ]; 
    }); 

    it('http call to obtain data', 
     inject(
      [DataService, MockBackend], 
      fakeAsync((service: DataService, backend: MockBackend) => { 
       backend.connections.subscribe((connection: MockConnection) => { 
        dataFromDbExpected = 'myData'; 
        let mockResponseBody: any = 'myData'; 
        let response = new ResponseOptions({ body: mockResponseBody }); 
        connection.mockRespond(new Response(response)); 

       }); 
       const parsedData$ = service.getDataFromDb() 
        .subscribe(response => { 
         console.log(response); 
         expect(response).toEqual(dataFromDbExpected); 
        }); 
      }))); 
}); 

我当然想测试与Observable.timer整体功能。我想有人可能想使用rxjs框架中的TestScheduler，但是我怎样才能告诉只重复定时器函数x次？我没有在打字稿上下文中找到任何使用它的文档。

编辑：我使用rxjs 5测试版6

编辑：新增工作角2.0.0最终版本例如：

describe('when getData',() => { 
    let backend: MockBackend; 
    let service: MyService; 
    let fakeData: MyData[]; 
    let response: Response; 
    let scheduler: TestScheduler; 

    beforeEach(inject([Http, XHRBackend], (http: Http, be: MockBackend) => { 
     backend = be; 
     service = new MyService(http); 
     fakeData = [{myfake: 'data'}]; 
     let options = new ResponseOptions({ status: 200, body: fakeData }); 
     response = new Response(options); 

     scheduler = new TestScheduler((a, b) => expect(a).toEqual(b)); 
     const originalTimer = Observable.timer; 
     spyOn(Observable, 'timer').and.callFake(function (initialDelay, dueTime) { 
      return originalTimer.call(this, initialDelay, dueTime, scheduler); 
     }); 
    })); 
    it('Should do myTest', async(inject([],() => { 
     backend.connections.subscribe((c: MockConnection) => c.mockRespond(response)); 
     scheduler.schedule(() => { 
      service.getMyData().subscribe(
       myData => { 
        expect(myData.length).toBe(3, 
         'should have expected ...'); 
       }); 
     }, 2000, null); 
     scheduler.flush(); 
    }))); 
}); 

Answer 1

您需要的TestScheduler注入内部定时器方法beforeEach部分：

beforeEach(function() { 
    this.scheduler = new TestScheduler(); 
    const originalTimer = Observable.timer; 
    spyOn(Observable, 'timer').and.callFake(function(initialDelay, dueTime) { 
    return originalTimer.call(this, initialDelay, dueTime, this.scheduler); 
    }); 
}); 

之后，你有时间完全控制与scheduleAbsolute：

this.scheduler.schedule(() => { 
    // should have been called once 
    // You can put your test code here 
}, 1999, null); 

this.scheduler.schedule(() => { 
    // should have been called twice 
    // You can put your test code here 
}, 2000, null); 

this.scheduler.schedule(() => { 
    // should have been called three times 
    // You can put your test code here 
}, 4000, null); 

this.scheduler.flush(); 

您需要scheduler.flush()才能启动TestScheduler。

编辑：如果您只希望测试X次，请按照您的意愿经常使用scheduleAbsolute函数（并以绝对毫秒为单位）。

EDIT2：我补充丢失的调度启动

EDIT3：我改之以应RxJs5