Support Time progression syntax

[prumand]

I couldn't get the following marble to run with jest-marbles, but it worked fine with the normal testScheduler setup. Cold and hot just give me frames for every letter/digit.

// standard rxjs setup
expectObservable(obs).toBe(' 5000ms b')

// jest-marbles
cold(' 5000ms b')
hot(' 5000ms b')

I hope that's enough info to reproduce.

npm info = jest-marbles@2.3.1

[just-jeb]

I'll look into this.

[just-jeb]

Ok, the issue is identified. jest-marbles use TestScheduler in the old way (outside of run method). Time progression syntax is not supported in this way.
I'll issue a new major version that uses run method but most likely it will take some time because the documentation has to be aligned and there are syntax differences between the two ways.
How urgent is this for you?

[prumand]

Thank you very much.

As you see, not urgent at all (vacation-time 🌴). I just used the rxjs TestScheduler.

[HanDDol]

Is it not implemented yet?

[just-jeb]

Unfortunately not yet. But any contribution is welcome.

[leonard84]

This explains, why I couldn't get my tests working. Any timeline on this change?

Is this also the reason why debounceTime doesn't seem to work. It only emits when the stream completes instead of after 250ms no matter how many frames - I use.

    it('debounce', () => {
      const input = cold('a--------------------------b-------------------------|', {a: 'demo', b: 'demo.w'})
      const expected = cold('--------------------------a--------------------------(b|)',
        {a: 'demo', b: 'demo.w'})

      expect(input.pipe(debounceTime(250))).toBeObservable(expected)
    });

Expected notifications to be:
  [{"frame": 260, "notification": {"error": undefined, "hasValue": true, "kind": "N", "value": ["com.demo.backend", "com.demo.webapp"]}}, {"frame": 530, "notification": {"error": undefined, "hasValue": true, "kind": "N", "value": ["com.demo.webapp"]}}, {"frame": 530, "notification": {"error": undefined, "hasValue": false, "kind": "C", "value": undefined}}]
But got:
  [{"frame": 530, "notification": {"error": undefined, "hasValue": true, "kind": "N", "value": ["com.demo.webapp"]}}, {"frame": 530, "notification": {"error": undefined, "hasValue": false, "kind": "C", "value": undefined}}]

[just-jeb]

Hey @leonard84, unfortunately time progression is still not supported and I'm struggling to see when I'll be free to do this. Contributions are welcome.
That being said I don't think your issue is related to this. Does it work if you use RxJs TestScheduler?
They did mention that the default time frame could change to 1 per - instead of 10 per - in future versions. What version you're using?

[sonic1981]

If your using TestScheduler you can achieve this using the inbuilt hot and cold methods without using jest-marbles at all, simply:

testScheduler.run(helpers  => {

      const { cold, expectObservable } = helpers;

};

cold has a slightly different syntax but at least it all supports proper timeframes. Not really sure what the point of a marble diagram library that doesn't support time is...seems a bit pointless given that you can achieve the same thing using existing libraries that work fine inside of jest 🤷‍♂️