具有第三方指令的 Angular2 Jasmine 单元测试组件

Question

组件是 https://github.com/valor-software/ngx-bootstrap下拉菜单。

在模板中我有这个:

    <span dropdown placement="bottom right">
      <a id="droplist-label" href="javascript:void(0)" dropdownToggle>
          <span>{{conf.title}}</span>
      </a>
      <ul class="dropdown-menu pull-right" *dropdownMenu>
        <li *ngFor="let item of items">
          <a class="dropdown-item" (click)="listClick(item.value)" href="javascript:void(0)">{{item.label}}</a>
        </li>
      </ul>
    </span>

在单击标签之前不会添加 ul - 因此我无法在测试中访问它。

调用点击:

let droplist = fixture.debugElement.query(By.css('#droplist-label')).nativeElement;
droplist.click();

不起作用 - 如果我尝试寻找 dropdown-menu 它是空的:

it('should test if droplist has title',  async(() => {
    fixture.detectChanges();
    let droplist = fixture.debugElement.query(By.css('#droplist-label')).nativeElement;
    droplist.click();

    fixture.whenStable().then(() => {
        let droplistOptions = fixture.debugElement.queryAll(By.css('.dropdown-item'));
        expect(droplistOptions.length).toBeGreaterThan(0);
    });
}));

该指令似乎有一个用于点击事件的主机监听器 - 我如何触发它以便 ul 变得可用？

Answer 1

我终于用 fakeAsync() 解决了同一个 pb :

it('should render submenus', fakeAsync(() => {

  fixture.detectChanges(); // update the view

  // trig submenus opening
  let toggleButtons = fixture.debugElement.nativeElement.querySelectorAll('[dropdownToggle]');
  toggleButtons.forEach(b => b.click());


  tick();                  // wait for async tasks to end
  fixture.detectChanges(); // update the view

  // then count how many items you got for each submenus.
  let droplistOptions1= fixture.debugElement.nativeElement.querySelectorAll('#first-ul > li')
  let droplistOptions2= fixture.debugElement.nativeElement.querySelectorAll('#second-ul > li')
  let droplistOptions3= fixture.debugElement.nativeElement.querySelectorAll('#third-ul > li')
  expect(droplistOptions1.length).toEqual(3);
  expect(droplistOptions2.length).toEqual(5);
  expect(droplistOptions3.length).toEqual(2);
}));

但我确信可以使用 async() 来做到这一点:我猜你只是错过了 fixture.detectChanges() 在 fixture.whenStable().then(...) 在您的初始尝试中。

---

此外，请记住将 BsDropdownModule 导入到您的测试平台中:

import { BsDropdownModule} from 'ngx-bootstrap/dropdown';
...
TestBed.configureTestingModule({
  imports: [
    BsDropdownModule.forRoot(),
  ],
  ...
});