fix: CalledPreviewMethodBeforeInitializationError (8.2)

[stevoland]

Fix this error in 8.2-alpha1 with large number of stories:

ERROR [SB_PREVIEW_API_0005 (CalledPreviewMethodBeforeInitializationError): Called `Preview.loadStory()` before initialization.

The preview needs to load the story index before most methods can be called. If you want
to call `loadStory`, try `await preview.initializationPromise;` first.

If you didn't call the above code, then likely it was called by an addon that needs to
do the above.]

What I did

Add waits for initialization

How to test

Start with large number of stories, eg: stevoland@aca843b

[dannyhw]

thanks @stevoland 🙏

[dannyhw]

seem to be getting a build error here

Error: src/View.tsx(151,25): error TS2445: Property 'storeInitializationPromise' is protected and only accessible within class 'Preview' and its subclasses.
Error: src/View.tsx(183,21): error TS2445: Property 'storeInitializationPromise' is protected and only accessible within class 'Preview' and its subclasses.

I wonder if theres another way to call it.

[stevoland]

Bah, sorry didn't get the tests to run locally.

The error message says initializationPromise but that's undefined. I'll have a dig around

[stevoland]

I guess we can just add a subclass and expose it https://github.com/storybookjs/react-native/blob/feat/v8/packages/react-native/src/Start.tsx#L211

[stevoland]

Hmm, actually leave this for now. There's a ready() method on preview to use but also I get another early initialisation error when web socket is enabled so needs more work

[stevoland]

Ok, I think this does the job now, thanks

[dannyhw]

sorry for not following up earlier I've had a lot going on, taking another look now

[dannyhw]

seems to be working, thanks for the fix 🙏