在 Jasmine 中使用 2 个不同的模拟进行测试

Question

我有一个这样的 ts 守卫：

@Injectable({
  providedIn: 'root'
})

export class AppEssentialsGuard implements CanActivate {

  private readonly DEFAULT_APP_ID = 'def';

  constructor(private appsService: AppsService) {}

  canActivate(next: ActivatedRouteSnapshot, state: RouterStateSnapshot): boolean {
    const url = this.getDefaultAppUrl();
    if (url) {
      window.open(url);
    }
    return false;
  }

  private getDefaultAppUrl(): string {
    const myApp = this.appsService.getAllApps()
      .find(app => app.appId === this.DEFAULT_APP_ID);
    return myApp ? myApp.url : null;
  }
}

我正在为它编写如下测试：

describe('AppEssentialsGuard', () => {
  let guard: AppEssentialsGuard;
  let appsService: AppsService;

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        mockProvider(RequesterService),
        {provide: AppsService, useClass: AppsServiceMock}
      ]
    });
    appsService = TestBed.inject(AppsService);
    guard = TestBed.inject(AppEssentialsGuard);
  });

  it('should be created', () => {
    expect(guard).toBeTruthy();
  });

  it( 'should open new default app window', () => {
    spyOn(window, 'open');
    let returnValue = guard.canActivate(null, null);
    expect( window.open ).toHaveBeenCalledWith("https://appstore.com/");
    expect(returnValue).toBeFalsy();
  });


});

现在对于快乐流测试，我使用在 useClass 中指定的 AppsServiceMock，它返回一组虚拟应用程序，其中包括一个 ID 为“def”的应用程序以通过测试。

我的问题是，我还想测试这个 url 返回一个空数组的情况，或者一个没有“def”应用程序的情况，我该如何测试这两种情况？我不知道如何使用另一个模拟

我是茉莉花的新手

谢谢！

Answer 1

您可以通过监视getAllApps 并在做出断言之前返回一个值来实现您正在寻找的行为。监视并返回一个值会忽略原始细节实现，并始终返回您指定的值。

// happy path;
it( 'should open new default app window', () => {
    spyOn(appService, 'getAllApps').and.returnValue([/* add an array of elements you would like */]);
    spyOn(window, 'open');
    let returnValue = guard.canActivate(null, null);
    expect( window.open ).toHaveBeenCalledWith("https://appstore.com/");
    expect(returnValue).toBeFalsy();
  });
// empty array path
it( 'should not open new default app window', () => {
    spyOn(appService, 'getAllApps').and.returnValue([]);
    spyOn(window, 'open');
    let returnValue = guard.canActivate(null, null);
    expect( window.open ).not.toHaveBeenCalled(); // change your assertion here
    expect(returnValue).toBeFalsy();
  });