使用Jasmine进行滚动测试

Question

我正在尝试使用Jasmine和Angular测试一个在滚动上执行某些操作的角度指令。

这是指令代码：

@Directive({
  selector: '[dfScroller]'
})
export class ScrollerDirective {
  @select(['module', 'sessionTimeout', 'showTimeoutWarning']) readonly showTimeoutWarning$: Observable<any>;
  debounceLastAction = debounce(() => { this.actions.updateLastActionTimestamp(); }, 1500);

  constructor(private actions: ModuleActions) {}

  hideToastComponent = () => {
    if (convertObservableToList(this.showTimeoutWarning$)) {
      this.actions.showTimeoutWarning(false);
    }
  }

  @HostListener('window:scroll') scrolling() {
    this.debounceLastAction();
    this.hideToastComponent();
  }

  @HostListener('click') clicking() {
    this.debounceLastAction();
    this.hideToastComponent();
  }
}

这是规范文件，我正在测试点击事件和滚动事件：

…
// Test case
describe('Directive: Scroller directive', async () => {
  compileAndCreate();

  it('Should be able to test the scroller directive on click', async () => {
    const debounceLastActionSpy = spyOn(directiveInstance, 'debounceLastAction').and.callThrough();
    const hideToastComponentSpy = spyOn(directiveInstance, 'hideToastComponent').and.callThrough();
    directiveEl.nativeElement.click();

    expect(debounceLastActionSpy).toHaveBeenCalled();
    expect(hideToastComponentSpy).toHaveBeenCalled();
  });

  it('Should be able to test the scroller directive on mouse wheel', async () => {
    const debounceLastActionSpy = spyOn(directiveInstance, 'debounceLastAction').and.callThrough();
    const hideToastComponentSpy = spyOn(directiveInstance, 'hideToastComponent').and.callThrough();
    directiveEl.nativeElement.scrollIntoView();

    expect(debounceLastActionSpy).toHaveBeenCalled();
    expect(hideToastComponentSpy).toHaveBeenCalled();
  });
});

如果我评论滚动测试的期望部分和整个点击测试，我可以看到所涵盖的方法。但是一旦我添加了期望，我就会收到一条错误消息，说明该方法从未被调用过。

我已经尝试了几件事：   - 用Karma运行单元测试，仍然出错。   - 从debounceLastAction中移除debounce，仍然出现错误。