Тест Жасмин на ngOnDestroy не проходит

Question

Я пытаюсь написать тест ngOnDestroy, используя jasmine в angular и получаю сообщение об ошибке Ожидается, что вызван spy ngOnDestroy. Может кто-нибудь сказать мне, в чем проблема

Компонент

export class DialogComponent implements AfterViewInit, OnDestroy {
  private readonly _onClose = new Subject<any>();

  public componentRef: ComponentRef<any>;
  public childComponentType: Type<any>;
  public onClose = this._onClose.asObservable();

  // add this:
  @ViewChild(InsertionDirective, { static: false })
  insertionPoint: InsertionDirective;

  constructor(public componentFactoryResolver: ComponentFactoryResolver,
              public cd: ChangeDetectorRef,
              public dialog: DialogRef) {
  }

  ngAfterViewInit() {
    this.loadChildComponent(this.childComponentType);
    this.cd.detectChanges();
  }

  ngOnDestroy() {
    if (this.componentRef) {
      this.componentRef.destroy();
    }
  }



  loadChildComponent(componentType: Type<any>) {
    const componentFactory = this.componentFactoryResolver.resolveComponentFactory(componentType);
    const viewContainerRef = this.insertionPoint.viewContainerRef;
    viewContainerRef.clear();
    this.componentRef = viewContainerRef.createComponent(componentFactory);
  }

  closeModal() {
    this.dialog.close();
  }
}

Тестовый компонент

describe('DialogComponent', () => {
  let component: DialogComponent;
  let fixture: ComponentFixture<DialogComponent>;


  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [SharedModule, DialogModule],
      providers: [DialogConfig, DialogRef ]
    })
    .overrideModule(BrowserDynamicTestingModule, { set: { entryComponents: [DialogComponent, ExampleComponent] } })
    .compileComponents();
  }));

  beforeEach(() => {

    fixture = TestBed.createComponent(DialogComponent);
    component = fixture.componentInstance;
    component.childComponentType = ExampleComponent;


    fixture.detectChanges();
  });


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


  fit('should call ngOnDestroy ', () => {
    spyOn(component, 'ngOnDestroy').and.callThrough();
    expect(component.ngOnDestroy).toHaveBeenCalled();
  });




});

Определение ComponentRef

export declare abstract class ComponentRef<C> {
    /**
     * The host or anchor [element](guide/glossary#element) for this component instance.
     */
    abstract readonly location: ElementRef;
    /**
     * The [dependency injector](guide/glossary#injector) for this component instance.
     */
    abstract readonly injector: Injector;
    /**
     * This component instance.
     */
    abstract readonly instance: C;
    /**
     * The [host view](guide/glossary#view-tree) defined by the template
     * for this component instance.
     */
    abstract readonly hostView: ViewRef;
    /**
     * The change detector for this component instance.
     */
    abstract readonly changeDetectorRef: ChangeDetectorRef;
    /**
     * The type of this component (as created by a `ComponentFactory` class).
     */
    abstract readonly componentType: Type<any>;
    /**
     * Destroys the component instance and all of the data structures associated with it.
     */
    abstract destroy(): void;
    /**
     * A lifecycle hook that provides additional developer-defined cleanup
     * functionality for the component.
     * @param callback A handler function that cleans up developer-defined data
     * associated with this component. Called when the `destroy()` method is invoked.
     */
    abstract onDestroy(callback: Function): void;
}

Answer 1

Нет события, которое инициирует вызов функции ngOnDestroy. Вместо этого вам следует вызвать ngOnDestroy в своем тесте, а затем проверить, выполняет ли он требуемую функциональность.

fit('should call ngOnDestroy ', () => {
  let childFixture: ComponentFixture<ExampleComponent>;
  component.componentRef = childFixture.componentRef;
  spyOn(component.componentRef, 'destroy').and.callThrough();
  component.ngOnDestroy();
  expect(component.componentRef.destroy).toHaveBeenCalled();
});