角度测试-ngBootstrapstypeahead

我目前正在使用ngBootstrap的自动完成机制(typeahead).现在我想要对输入事件的每个序列调用一个方法进行单元测试.我的测试用例的错误目前是:Cannot read property 'pipe' of undefined

HTML:

零件:

public ngOnInit() {
    this.search = (text$: Observable) =>
      text$.pipe(
        tap(() => {
          this.isSearching = true;
          this.searchFailed = false;
        }),
        debounceTime(750),
        distinctUntilChanged(),
        switchMap(term =>
          this.cityService.getLocation(term).pipe(
            tap((response) => {
              this.searchFailed = response.length === 0;
              this.isSearching = false;
            })))
      );
  }

spec.ts

  it('should call spy on city search', fakeAsync(() => {
    component.user = {uid: 'test', username: 'mleko', location: null, description: null};
    const spy = (cityStub.getLocation).and.returnValue(of['München Bayern']);

    fixture.detectChanges();
    const compiled: DebugElement = fixture.debugElement.query(By.css('#locationEdit'));
    compiled.nativeElement.value = 'München';
    compiled.nativeElement.dispatchEvent(new Event('input'));

    tick(1000);
    fixture.detectChanges();

    expect(spy).toHaveBeenCalled();
  }));

有人可以帮我嘲笑这个.搜索得当吗？

编辑

通过@dmcgrandle的精彩建议,我不需要渲染HTML并模拟输入事件,以检查输入事件是否正常工作.我宁愿做一个Observable,它会发出值并将它分配给函数.一种方法是:

  it('should call spy on city search', fakeAsync(() => {
    const spy = (cityStub.getLocation).and.returnValue(of['München Bayern']);

    component.ngOnInit();
    const textMock = of(['M', 'Mün', 'München']).pipe(flatMap(index => index));

    component.search(textMock);

    tick();

    expect(spy).toHaveBeenCalled();
  }));

但问题仍然是,component.search不要打电话给间谍.在switchMap运算符的搜索函数中,我添加了一个console.log以查看函数是否发出了值.但事实并非如此.也许有人可以为我的问题提供stackblitz.:)