如何用茉莉花大理石创建一个Observable定时器测试？

Question

我无法在函数startTimer中创建测试计时器Observable的测试。我使用的是RXJS的6.3.1版本。

这是我的代码：

private createSubscribe(): void {
  if (this.timer) {
    this.subscription = this.timer.subscribe(() => {
      this.cream().then(() => {
        this.subscription.unsubscribe();
        this.subscription = null;
        this.timer = null;
        this.startTimer(this.config.period);
      });
    });
  }
}

private startTimer(period): void {
  if (period) {
    this.timer = timer(period * 1000);
    this.createSubscribe();
  }
}

Answer 1

我使用以下方法解决问题：

it('startTimer: should call createSubscribe and set timer with observable emited in 5000ms.', () => {

  const scheduler = new TestScheduler((actual, expected) => {
    expect(actual).toEqual(expected);
  });

  scheduler.run(helpers => {
    const { expectObservable } = helpers;
    const period = 5;
    const expected = '5000ms (a|)';
    spyOn(helper, <any>'createSubscribe');

    helper['startTimer'](period);

    expectObservable(helper['timer']).toBe(expected, {a : 0});
    expect(helper['createSubscribe']).toHaveBeenCalled();
  });
});