spyOn 无法监视依赖服务的方法

Question

我正在测试 AuthService，它使用另一个 HelperService.

将用户登录信息发送到服务器

public authServiceSigninUser(user:UserSigninInfo):any{
    console.log('In authServiceSigninUser. contacting server at '+this.API_URL +this.SIGNIN_USER_URL +" with user data "+user+ " with httpOptions "+httpOptions.withCredentials + ","+httpOptions.headers ); //TODOM password should be sent in encrypted format.

    let signinInfo= new UserSigninAPI(user);
    let body = JSON.stringify(signinInfo);
    return this.helperService.sendMessage(this.SIGNIN_USER_URL,body,httpOptions)
  }

我正在尝试按如下方式测试 authServiceSigninUser 方法，但是当我运行规范时，出现错误 Error: <spyOn> : sendMessage() method does not exist Usage: spyOn(<object>, <methodName>)。为什么？

describe('authServiceSigninUser test suite',()=>{
  beforeEach(()=>{
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [AuthService, HelperService]
    });
  });
  fit('should sign in user',()=>{
    let spy:any;
    let helper = TestBed.get(HelperService);
    let authService = TestBed.get(AuthService);
    let userSignIn = new UserSigninInfo("test@test.com","test");
    let httpMock = TestBed.get(HttpTestingController);
    spyOn(helper.sendMessage,'sendMessage');
    let observable:Observable<HttpEvent<any>> = authService.authServiceSigninUser(userSignIn);
    let subscription = observable.subscribe((event)=>{
      console.log('event from authService',event);
    });
    const responseData = { result: 'success', ['additional-info']: 'login success' };
    let httpEvent:HttpResponse<any> = new HttpResponse<any>({body:responseData});
    expect(helper.sendMessage).toHaveBeenCalled();//ERROR here
    const mockReq:TestRequest = httpMock.expectOne(environment.apiUrl+environment.signinUserUrl); //Expect that a single request has been made which matches the given URL, and return its mock
    //once mocking of sending request is done, mock receiving a response. This will trigger the logic inside subscribe function
    mockReq.flush(httpEvent); //flush method provides dummy values as response
    httpMock.verify();//verify checks that there are no outstanding requests;

  });
});

Answer 1

看来正确的方法是spyOn(helper,'sendMessage');，而不是spyOn(helper.sendMessage,'sendMessage');

spyOn 无法监视依赖服务的方法

spyOn not able to spy on the method of a dependent service

angular-test

angular6