错误：已调用spy MovieService.getWatchListedMovies已被调用。角度单位测试

Question

• 一个名为watchlist的组件文件，它依赖于MovieService（服务）来获取电影。
• 调用ngOnInit（）将调用MovieService.getWatchlistedMovies（）
• 组件代码如下，

export class WatchlistComponent implements OnInit {

  movies: Array<Movie>;
  movieType:string;
  
  constructor(private movieService:MovieService,private route:ActivatedRoute) { 

    this.movies=[];
    this.route.data.subscribe((data)=>{
      this.movieType=data.movieType
    });
   
  }

  ngOnInit() {

    this.movieService.getWatchListedMovies()
    .subscribe((movies)=>{
     this.movies.push(...movies);
       },
       this.handleErrors()
       );

  }

• 使用movieService（Service）上的jasmine.spy对象对组件（监视列表）进行单元测试
• watchlist.spec.ts文件代码如下，

describe('WatchlistComponent', () => {
  let component: WatchlistComponent;
  let fixture: ComponentFixture<WatchlistComponent>;
  let movieServiceFake:jasmine.SpyObj<MovieService>;
  let movieService;
  let stubTmdbMovies: Movie[];
  beforeEach(async(() => {
    movieServiceFake = jasmine.createSpyObj('MovieService', ['getWatchListedMovies']);


    TestBed.configureTestingModule({
      imports: [MovieModule,
        RouterTestingModule,
        HttpClientTestingModule],
      providers: [{ provide: MovieService, useValue: movieServiceFake }]
    })
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(WatchlistComponent);
    component = fixture.componentInstance;
    movieServiceFake = TestBed.get(MovieService);
  });

  it('should create watchlist', () => {
    expect(component).toBeTruthy();
  });

  it('should call ngOnInIt', () => {
    //Arrange
    let spyOnComponent = spyOn(component, 'ngOnInit');
    movieServiceFake.getWatchListedMovies.and.callFake(() => { return of(stubTmdbMovies) });
    //Act
    component.ngOnInit();
    //Assert
    expect(spyOnComponent).toHaveBeenCalled();
    expect(movieServiceFake.getWatchListedMovies).toHaveBeenCalled();//error line
  });
});

`MovieModule我在哪里注册了watchlist和MovieService。如下

@NgModule({
  imports: [
    CommonModule,
    HttpClientModule,
    MovieRouterModule,
    MatCardModule,
    MatButtonModule,
    MatSnackBarModule,
    FormsModule,
    ReactiveFormsModule,
    MatInputModule
      ],
  declarations: [ContainerComponent,TmdbContainerComponent,TumbnailComponent, WatchlistComponent, MovieDetailsComponent],
  
  exports:[
    MovieRouterModule,
    TumbnailComponent,
    ContainerComponent,
    TmdbContainerComponent
  ],
  providers:[
    MovieService
  ]
})
export class MovieModule { }

Answer 1

只是一个猜测，尝试移动线

movieServiceFake = TestBed.get(MovieService);

进入测试的开始，就像

it('should call ngOnInIt', () => {
    movieServiceFake = TestBed.get(MovieService);
    ....
});