angular - fakeAsync 不适用于 debounceTime

Question

我正在尝试为 Angular 中的函数编写单元测试应用程序 debounceTime ( rxjs )。并使用 fakeAsync用于异步测试。
看起来在测试中 debounceTime即使我没有设置 tick() 也会立即解决或以较小的间隔设置它，例如 tick(500) .

例如 delay(1000)而不是 debounceTime(1000) fakeAsync工作正常。

测试 :

describe('rr', () => {
    it('should get Date diff correctly in fakeAsync with rxjs scheduler', fakeAsync(() => {
        let result = null;
        of ('hello').pipe(debounceTime(1000)).subscribe(v => { result = v; });
        expect(result).toBeNull(); // But it is 'Hello' - debounceTime resolves immediately
        tick(1000);
        expect(result).toBe('hello');
...
  }));
})

stackblitz : https://stackblitz.com/edit/angular-ohhi9e?file=src%2Fapp%2Fapp.component.spec.ts

Answer 1

of运算符(operator)在收到通知后立即完成。如果不需要额外的通知，debounceTime不需要等待，从而通知发出完整通知的那一刻。

要实现您的结果，请尝试使用像 Subject 这样的长生命周期可观察对象。 .

describe('rr', () => {
    it('should get Date diff correctly in fakeAsync with rxjs scheduler', fakeAsync(() => {
        let result = null;
        new BehaviourSubject ('hello').pipe(debounceTime(1000)).subscribe(v => { result = v; });
        expect(result).toBeNull();
        tick(1000);
        expect(result).toBe('hello');
...
  }));
})

来源: debounceTime on GitHub

_complete() { this.debouncedNext(); ... }