Angular 測試 NullInjectorError：StaticInjectorError（DynamicTestModule）[UsersEffects -> Actions]：

Question

我正在使用 Angular Jasmine 編寫 uit 測試。 我收到以下錯誤：

NullInjectorError：StaticInjectorError（DynamicTestModule）[UsersEffects -> Actions]：StaticInjectorError（平台：核心）[UsersEffects -> Actions]：NullInjectorError：沒有提供操作！

我的 spec.ts 文件是：

describe('UsersComponent', () => {
  let component: UsersComponent;
  let fixture: ComponentFixture<UsersComponent>;
  let dialogSpy: jasmine.Spy;
  let dialogRefSpyObj = jasmine.createSpyObj({ afterClosed : of({}), close: null });
  dialogRefSpyObj.componentInstance = { body: '' };

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [
        MaterialModule,
        SharedModule,
        ReactiveFormsModule,
        StoreModule.forRoot({}),
        StoreModule.forFeature('Users', reducer),
        HttpClientModule,
        UnitTestModule,
        BrowserAnimationsModule,
        TranslateModule.forRoot({
          loader: {
            provide: TranslateLoader,
            useClass: DummyTranslateLoader,
          },
        }),
      ],
      schemas: [NO_ERRORS_SCHEMA],
      declarations: [],
      providers: [Store, UsersService],
    })
    .compileComponents();
  }));

  afterEach(() => {
    TestBed.resetTestingModule();
  });

  beforeEach(() => {
    fixture = TestBed.createComponent(UsersComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  beforeEach(() => {
    dialogSpy = spyOn(TestBed.get(MatDialog), 'open').and.returnValue(dialogRefSpyObj);
  });

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

我還添加了這是 app.module.ts：

StoreModule.forRoot({}),
EffectsModule.forRoot([]),

我可能會錯過什么？

Answer 1

下面的代碼解決了 NullInjectorError: No provider for Actions: 在我的組件中：

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { Actions } from '@ngrx/effects';
import { provideMockActions } from '@ngrx/effects/testing';
import { MockStore, provideMockStore } from '@ngrx/store/testing';
import { YourComponent } from './your.component';

describe('YourComponent ', () => {
   let component: YourComponent ;
   let fixture: ComponentFixture<YourComponent>;
   let store: MockStore;
   let actions: Actions;
   beforeEach(async () => {
     await TestBed.configureTestingModule({
     declarations: [YourComponent ],
     providers: [
       provideMockStore(),
       provideMockActions(() => actions)
     ]
   })
  .compileComponents();
});

beforeEach(() => {
  fixture = TestBed.createComponent(YourComponent );
  component = fixture.componentInstance;
  store = TestBed.inject(MockStore);
  actions = TestBed.inject(Actions);
  fixture.detectChanges();
});

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

Answer 2

在您的測試中，您應該使用 NGRX 提供的 Mock 元素：

let store: MockStore<any>

...

TestBed.configureTestingModule({
   providers: [
   ...,
   provideMockStore()
   ]
})

...

store = TestBed.get(Store)