如何对这种效果进行单元测试（使用 {dispatch: false}）？

Question

ngrx 和单元测试初学者在这里。我有以下效果：

@Injectable()
export class NotificationEffects {
  @Effect({dispatch: false})
  notificationShow$ = this.actions$
    .ofType(notificationAction.NOTIFICATION_SHOW)
    .do((action: notificationAction.NotificationShowAction) => {
      this.notificationService.info(action.payload.config);
    });

  constructor(private actions$: Actions, private notificationService: NotificationService) {}
}

具体来说，我想测试一下notificationService方法info是否被调用了。我该怎么做？

我遵循了这些示例，但没有找到解决方案：

https://netbasal.com/unit-test-your-ngrx-effects-in-angular-1bf2142dd459 https://medium.com/@adrianfaciu/testing-ngrx-effects-3682cb5d760e https://github.com/ngrx/effects/blob/master/docs/testing.md

Answer 1

如果有人感兴趣但没有明确订阅效果并且只使用jasmine-marbles

it('should call a notification service method info with a payload', () => {
    actions$ = cold('a', { a: new notificationAction.NotificationShowAction(payload) });
    
    // `toBeObservable` will subscribe the effect and does the trick
    expect(effects.notificationShow$).toBeObservable(actions$);
    expect(service.info).toHaveBeenCalledWith(payload);
  });

Answer 2

最简单（官方建议）的方法是这样做：

    it('should navigate to the customers detail page', () => {
      actions$ = of({ type: '[Customers Page] Customer Selected', name: 'Bob' });

      // create a spy to verify the navigation will be called
      spyOn(router, 'navigateByUrl');

      // subscribe to execute the Effect
      effects.selectCustomer$.subscribe();

      // verify the navigation has been called
      expect(router.navigateByUrl).toHaveBeenCalledWith('customers/bob');
    });

这里是the source。

Answer 3

it('should call a notification service method info with a payload', () => {
    actions$ = cold('a', { a: new notificationAction.NotificationShowAction(payload) });
    effects.notificationShow$.subscribe(() => {
      expect(service.info).toHaveBeenCalledWith(payload);
    });
  });

它运作良好，但问题是发生错误时。在这种情况下，错误不会报告给测试运行者（在我的情况下是开玩笑的）。我需要添加 try catch 块来获取错误：

   it('should call a notification service method info with a payload', () => {
        actions$ = cold('a', { a: new notificationAction.NotificationShowAction(payload) });
        effects.notificationShow$.subscribe(() => {
            try {
                expect(service.info).toHaveBeenCalledWith(payload); 
            } catch (error) {
                fail('notificationShow$: ' + error);
            }
        });
    });

Answer 4

所以就这么简单：

describe('notificationShow$', () => {
  let effects: NotificationEffects;
  let service: any;
  let actions$: Observable<Action>;
  const payload = {test: 123};

  beforeEach( () => {
    TestBed.configureTestingModule( {
      providers: [
        NotificationEffects,
        provideMockActions( () => actions$ ),
        {
          provide: NotificationService,
          useValue: jasmine.createSpyObj('NotificationService', ['info'])
        }
      ]
    } );

    effects = TestBed.get(NotificationEffects);
    service = TestBed.get(NotificationService);
  });

  it('should call a notification service method info with a payload', () => {
    actions$ = cold('a', { a: new notificationAction.NotificationShowAction(payload) });
    effects.notificationShow$.subscribe(() => {
      expect(service.info).toHaveBeenCalledWith(payload);
    });
  });
});