为什么我在使用ngrx的延迟加载的Angular 6应用程序的单元测试中得到“没有ReducerManager的提供者！”错误？

Question

我有一个使用ngrx的延迟加载Angular 6应用程序。我有一个：

app.module.ts
shared.module.ts
core.module.ts

核心模块具有页脚和页眉等内容。这里没有store / ngrx相关的东西，但是头部的单元测试（在实现ngrx之前工作）继续失败并出现以下错误：

StaticInjectorError(Platform: core)[StoreFeatureModule -> ReducerManager]: 
    NullInjectorError: No provider for ReducerManager!

我唯一能想到的是StoreModule没有进口到CoreModule。但是应该吗？当标题与状态无关时，为什么测试失败？

app.module.ts

@NgModule({
declarations: [
    AppComponent,
    LoginComponent,
],
imports: [
    BrowserModule,
    AppRoutingModule,
    CoreModule,
    SharedModule.forRoot(),
    StoreModule.forRoot({}),
    EffectsModule.forRoot([]),
    !environment.production ? StoreDevtoolsModule.instrument({
        maxAge: 5   // retains last 5 states
    }) : []
],
providers: [],
bootstrap: [ AppComponent ]

})

core.module.ts

@NgModule({
    imports: [
        CommonModule,
    ],
    exports: [
        CommonModule,
        HeaderComponent,
        FooterComponent
    ],
    declarations: [
        HeaderComponent, 
        FooterComponent, 
    ]
})

shared.module.ts

@NgModule({
    imports: [
        CommonModule,
        HttpClientModule
    ],
    exports: [
        CommonModule,
        MyComponent
    ],
    declarations: [ MyComponent]
})
export class SharedModule {

** header.component.spec.ts **

describe('HeaderComponent', () => {
    let component: HeaderComponent;
    let fixture: ComponentFixture<HeaderComponent>;
    let debugEl: DebugElement;

    beforeEach(async(() => {
        TestBed.configureTestingModule({
            imports: [ 
                ProductsModule,
                CustomersModule
        ],
        declarations: [ HeaderComponent ],
        providers: [
            { provide: myService, useValue: new MyService() },
        ],
    })
    .compileComponents();
}));

beforeEach(() => {
    fixture = TestBed.createComponent(HeaderComponent);
    component = fixture.componentInstance;
    debugEl = fixture.debugElement;
    fixture.detectChanges();
});

Answer 1

因为您的组件使用NgRx商店，所以您还必须在TestBed中导入商店。

Answer 2

import { Store, StoreModule } from '@ngrx/store';

describe('test:', () => {
   beforeEach(() => {
   TestBed.configureTestingModule({
   imports: [
    HeldMessagesTabsPageModule,
    StoreModule.forRoot(
      {
        messagesRoot: combineReducers(reducers.reducers)
      },
      {
        initialState: { messagesRoot: { messagesRoot: { template: templateInitialState } } }
      }
    )
  ],

  const store: Store<reducers.State>;
}

beforeEach(() => {
  store = TestBed.get(Store);
  spyOn(store, 'dispatch').and.callThrough();
});