[Addon-Knobs] Fixed addon for RN

[Gongreg]

Issue: #1586 Addon-knobs wasn't working on React Native

After cleanup done in 4c1daab addon wasn't breaking RN (since channel is not set while user is not connected to between app and browser).

What I did

Pretty much reverted the change back.

How to test

Adding knob examples to crna and react-vanilla-apps in a separate pr.

[codecov]

Codecov Report

Merging #1635 into master will increase coverage by 0.14%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #1635      +/-   ##
==========================================
+ Coverage   21.13%   21.27%   +0.14%     
==========================================
  Files         247      244       -3     
  Lines        5578     5386     -192     
  Branches      672      664       -8     
==========================================
- Hits         1179     1146      -33     
+ Misses       3879     3753     -126     
+ Partials      520      487      -33

Impacted Files	Coverage Δ
addons/knobs/src/index.js	0% <ø> (ø)	⬆️
addons/knobs/src/KnobManager.js	32% <0%> (-3.42%)	⬇️
lib/ui/src/modules/api/actions/api.js	49.42% <0%> (-1.06%)	⬇️
.../src/manager/containers/CommentsPanel/dataStore.js	34.78% <0%> (ø)	⬆️
lib/ui/src/modules/ui/containers/left_panel.js	25.71% <0%> (ø)	⬆️
addons/events/src/components/Event.js	0% <0%> (ø)	⬆️
addons/storyshots/src/require_context.js	0% <0%> (ø)	⬆️
addons/knobs/src/components/types/Object.js	5.81% <0%> (ø)	⬆️
addons/info/src/components/Story.js	76.19% <0%> (ø)	⬆️
addons/info/src/components/Node.js	38.88% <0%> (ø)	⬆️
... and 21 more

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[danielduan]

is there anything preventing us from merging this? would love to get this into the next patch release.

[ndelangen]

Code LGTM, maybe @tmeasday wants to veto this and merge?

[tmeasday]

I don't really understand @Gongreg's comment.

Are you saying that it was broken after the refactor and this fixes it? And what do you mean about the channel? (sorry too many negatives in the sentence, I can't parse it ;) )

[Gongreg]

@tmeasday, Yes, I mean it broke after refactor and this commit fixes it.

By channel I mean that in RN app the channel is not instantly set. See this code:

app/react-native/src/preview/index.js

getStorybookUI(params = {}) {
    return () => {
      let channel = addons.getChannel();
      if (params.resetStorybook || !channel) {
        ...
        channel = createChannel({ url });
        addons.setChannel(channel);
      }
      ...
  }

And after refactor the code addons.getChannel() existed in global scope so it was required before channel was set. It is difficult to explain, but we have to require channel only before sending event in it, not at the start of the program.

[tmeasday]

Thanks for that @Gongreg, yes it makes perfect sense to me (cf #1191)! I just was making sure I understood what you were saying correctly.

I haven't had a chance to test this but the code changes make sense to me.

[Gongreg]

I also added examples in #1636 for RN, so at least we could see in future if it stops working. But the pr checks screams to me about code duplication. I just have other priorities atm to fix it.

[ndelangen]

Either of you want to merge this then? @Gongreg @tmeasday