angular - 如何在@ngrx/data 中对 EntityCollectionServiceBase 进行单元测试？

Question

我有一个虚拟服务:

export class PatientService extends EntityCollectionServiceBase<Patient> {
  constructor(serviceElementsFactory: EntityCollectionServiceElementsFactory) {
    super('Patient', serviceElementsFactory);
  }
}

我有以下测试:

describe('PatientService', () => {
  let service: PatientService;

  beforeEach(() => {
    TestBed.configureTestingModule({});
    service = TestBed.inject(PatientService);
  });

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

它给了我:
NullInjectorError: No provider for EntityCollectionServiceElementsFactory
所以我更新如下:

describe('PatientService', () => {
  let service: PatientService;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [EntityDataModuleWithoutEffects.forRoot(entityConfig)],
      providers: [provideMockStore()],
    });
    service = TestBed.inject(PatientService);
  });

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

但现在它给了我:
NullInjectorError: No provider for ScannedActionsSubject!
如何正确修复我的测试？

Answer 1

是的，你很亲近，就那样做。您需要在测试台中提供配置所需的一切。

在我们的例子中，这意味着 PatientService应提供作为测试单位和EntityCollectionServiceElementsFactory应作为其依赖项提供。

但是EntityCollectionServiceElementsFactory有自己的依赖项:EntityDispatcherFactory , EntityDefinitionService , EntitySelectorsFactory和 EntitySelectors$Factory .我们不想提供，因为它们可能有自己的依赖关系，使我们的生活变得更糟。

要修复它，让我们简单地 sub EntityCollectionServiceElementsFactory .

describe('PatientService', () => {
  let service: PatientService;

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        PatientService,
        {
          provide: EntityCollectionServiceElementsFactory,
          // our stub
          useValue: {
            methodsToFake: jasmine.createSpy(),
            // ....
          },
        },
      ],
    });
    service = TestBed.inject(PatientService);
  });

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

同样为了避免将来模拟依赖项及其方法的痛苦，您可以使用 ng-mocks .然后测试看起来像这样:

describe('PatientService', () => {
  let service: PatientService;

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        PatientService,
        {
          provide: EntityCollectionServiceElementsFactory,
          useValue: MockService(EntityCollectionServiceElementsFactory),
        },
      ],
    });
    service = TestBed.inject(PatientService);
  });

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