Angular2集成测试，如何测试子组件在其模板中调用其父组件的方法

import { Component } from '@angular/core';

@Component({
  selector: 'app-parent',
  template: `
    <app-child (onChildEvent)="handleChildEvent($event)"></app-child>
  `
})
export class ParentComponent {
  handleChildEvent(event: any) {
    // 处理子组件事件的逻辑
  }
}

import { Component, Output, EventEmitter } from '@angular/core';

@Component({
  selector: 'app-child',
  template: `
    <button (click)="triggerEvent()">触发事件</button>
  `
})
export class ChildComponent {
  @Output() onChildEvent = new EventEmitter<any>();

  triggerEvent() {
    this.onChildEvent.emit('子组件触发的事件');
  }
}

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { ParentComponent } from './parent.component';
import { ChildComponent } from './child.component';

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

  beforeEach(async () => {
    await TestBed.configureTestingModule({
      declarations: [ParentComponent, ChildComponent]
    }).compileComponents();
  });

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

  it('should call parent component method when child component triggers event', () => {
    spyOn(component, 'handleChildEvent');
    const childComponent = fixture.debugElement.nativeElement.querySelector('app-child');
    childComponent.triggerEvent();
    expect(component.handleChildEvent).toHaveBeenCalledWith('子组件触发的事件');
  });
});

ng test