RxJs - 有损 zip 大理石测试

RxJs - lossy zip marble testing

正在关注此操作员的 post I've decided to write a marble test

这是一个基本测试:

  it('Test lossy zip', () => {

    const a = hot('a---a--------a-');
    const b = hot('--b----b---b---');

    const observable = zip(
      a.pipe(take(1)),
      b.pipe(take(1))
    ).pipe(
      mergeMapTo(from(['1'])),
      repeat()
    );
    const expected = cold('--1----1-----1-');
    expect(observable).toBeObservable(expected);
  });

此测试按预期通过。然而,当我决定像这样发射两次时,它失败了:

const a = hot('a---a--------a-');
const b = hot('--b----b---b---');

const observable = zip(
  a.pipe(take(1)),
  b.pipe(take(1))
).pipe(
  mergeMapTo(from(['1', '2'])), //Here, emitting two items instead of one
  repeat()
);

我希望得到的 observable 看起来像这样:

const expected = cold('--(12)----(12)-----(12)-');

或者至少像这样:

const expected = cold('--12---12----12-');

然而他们都失败了。

jasmine-marbles 的错误还是我的预期有误?

貌似根据官方documentation(我没看够)括号和群里的内容占了相应的帧数:

'--(abc)-|': on frame 20, emit a, b, and c, then on frame 80 complete

这意味着组发射的工作测试如下所示:

  it('Should emit a grouped value', () => {

    const a = hot('a------a---------a---');
    const b = hot('--b-------b----b-----');

    const observable = zip(
      a.pipe(take(1)),
      b.pipe(take(1))
    ).pipe(
      mergeMapTo(from(['1', '2'])),
      repeat()
    );

    const expected = cold('--(12)----(12)---(12)');
    expect(observable).toBeObservable(expected);
  });