fix: image mock in jest setup

[delphinebugner]

Summary:

resolveAssetSource should not return nothing by default in jest as some librairies (ex: react native fast image) rely on it!
They use it to compute the image source ; without this mock implementation, all sources disappear from images in test environnement - and we do test them a lot in test env (may be the only part of Images we actually look at in snapshots! )

Relates to issue #41907 -> not sure it fixes though, as in test the "require" source resolves to an object with assetFileTransformer - still having no width and height in output even with the real resolveAssetSource

It was introduced in version 0.73, where Image mock was changed - see PR #36996

Changelog:

[GENERAL][FIXED] - fix jest setup for Image.resolveAssetSource

Test Plan:

Here is a simple test rendering a FastImage with source = { uri : "some-string"} :

Without the fix : source is "undefined" in test :

With the fix :

the console.log comes from react native fast image and indicates that source is correctly retrieved

I also tested passing a require(../path.png) as source :
Without the fix :

With the fix :

[ryancat]

If this works before PR #36996, is it possible to just remove the line for resolveAssetSource and use the original defaults?

[idrissakhi]

@delphinebugner agree with @ryancat we should remove the line so it's require the actual ImageResolver to get the real image data such as width ... etc

[delphinebugner]

Yes you're right, I was going too quicly, we should absolutely keep what's ImageResolver normally do... Additional question is, should we also check and eventually remove other methods mocked in PR #36996?

  .mock('../Libraries/Image/Image', () => {
    const Image = mockComponent('../Libraries/Image/Image');
    Image.getSize = jest.fn();
    Image.getSizeWithHeaders = jest.fn();
    Image.prefetch = jest.fn();
    Image.prefetchWithMetadata = jest.fn();
    Image.queryCache = jest.fn();
    Image.resolveAssetSource = jest.fn();

    return Image;
  })

I checked for iOS and all of those methods just call native module ImageLoader ; resolveAssetSource is the only exception!

The original issue was about Image.getSize getting undefined in test after jest setup : #35518
I was unable to reproduce the error, even by removing the mocked methods - maybe something else fixed it? I checked the native mock of ImageLoader, and it does have the getSize function ; even if something we can do could be to add getSizeWithHeaders and queryCache to it!

[ifero]

Is there an ETA to merge this bit?

[delphinebugner]

Closed because I opened a newer + more exhaustive PR on the topic: #43497