Mocked的弹珠服务方法不发值。

Question

我正在使用弹珠为服务创建单元测试。经过测试的服务方法(我只留下了一个有问题的片段)

updatePayment(payment: Partial<Payment>, familyId: string): Observable<void> {
  return this.authenticationService.getUser()
}

我已经创建了一个服务模拟

function getAuthenticationServiceSpy() {
   ...

  // tslint:disable-next-line: max-line-length
  const authenticationServiceSpy: jasmine.SpyObj<AuthenticationService> = jasmine.createSpyObj(
    'AuthenticationService', ['getUser']
  );
  authenticationServiceSpy.getUser.and.returnValue(hot('--a', { a: user }));

  return authenticationServiceSpy;
}

export interface IAuthenticationServiceMock {
  getService: () => jasmine.SpyObj<AuthenticationService>;
  user: User;
}

// tslint:disable-next-line: max-line-length
export const AuthenticationServiceMock: () => IAuthenticationServiceMock = () => ({
  getService: getAuthenticationServiceSpy,
  user
});

我用它来规范服务

describe('PaymentsService', () => {
  let service: PaymentsService;
  let authenticationServiceSpy: jasmine.SpyObj<AuthenticationService>;
  let authenticationServiceMock: IAuthenticationServiceMock;

  const scheduler = new TestScheduler((actual, expected) => {
    expect(actual).toEqual(expected);
  });

  beforeEach(() => {
    authenticationServiceMock = AuthenticationServiceMock();
    authenticationServiceSpy = authenticationServiceMock.getService();

    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [
        { provide: AuthenticationService, useValue: authenticationServiceSpy }
      ]
    });
    service = TestBed.get(PaymentsService);
    httpTestingController = TestBed.get(HttpTestingController);
  });

  it('should do the thing', () => {
      const mockedFamilyId = 'familyId-1';
      const updatedPayment = {};
      service.updatePayment(updatedPayment, mockedFamilyId)
        .subscribe(payment => {
          expect(1).toBe(2); // should fail
        });
    }
  );
});

这个测试成功的问题，不应该是这样的。据我了解 authenticationServiceSpy.getUser() 没有发出值，但我不明白为什么。如果我改变

authenticationServiceSpy.getUser.and.returnValue(hot('--a', { a: user }));

到

authenticationServiceSpy.getUser.and.callFake(() => hot('--a', { a: user }));