如何在Angular -cli 4单元测试中从输入模拟key up事件

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';

let component: YourComponent;
let fixture: ComponentFixture<YourComponent>;

beforeEach(async(() => {
  TestBed.configureTestingModule({
    declarations: [ YourComponent ]
  })
  .compileComponents();
}));

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

it('should trigger keyup event on input', () => {
  const inputElement: DebugElement = fixture.debugElement.query(By.css('input')); // 获取输入框元素
  const inputNativeElement: HTMLInputElement = inputElement.nativeElement; // 获取输入框的原生DOM元素

  spyOn(component, 'onKeyUp'); // 监听组件中的onKeyUp方法

  inputNativeElement.value = 'test value'; // 设置输入框的值
  inputNativeElement.dispatchEvent(new Event('keyup')); // 模拟keyup事件

  fixture.detectChanges();

  expect(component.onKeyUp).toHaveBeenCalled(); // 验证onKeyUp方法是否被调用
});