Babel: Ensure story files not transpiled earlier than ES2017

[kasperpeulen]

What I did

Make sure that stories files get not transpiled by babel further than the browser we support.

The purpose of this is to preserve the play: async ({ mount }) => { destructure code, which we dynamically test at runtime. It's important that we be able to do this at runtime (instead of during compilation) because it will allow us to support Playwright-style fixtures in the future -- an option that we want to keep open.

We believe it is a safe, nonbreaking change, because we are scoping the restriction to story files only and not to the user's components. Plus we already apply the same browser targets to the manager & preview-api code, so it is consistent with existing constraints!

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Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
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• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

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  • bug: Internal changes that fixes incorrect behavior.
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[greptile-apps]

PR Summary

• Updated code/core/src/core-server/presets/common-preset.ts to prevent story files from being transpiled beyond supported browsers.
• Added Babel configuration override in code/core/src/core-server/presets/common-preset.ts to target specific browser versions.
• Re-applied default Storybook Babel override in code/frameworks/nextjs/src/preset.ts to ensure compatibility with supported browsers.
• Included specific browser targets for Chrome, Safari, and Firefox in code/frameworks/nextjs/src/preset.ts.

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[valentinpalkovic]

Shouldn’t we load babelDefault instead from the presets and apply it?

[kasperpeulen]

I'm not sure what you mean with this, do you mean to somehow reuse the babel preset override loaded in:
code/core/src/core-server/presets/common-preset.ts?

So in theory options.overrides should actually contain that preset/override, but it gets ignored as the include regex doesn't match the filename in line 62.

That is why I need to copy the override again.
I think we should solve it in:
#28467

But won't be easy I imagine.

[JReinhold]

If you want to be really exact you probably want to:

1. Add a dot at the beginning, to not match the-cool-stories.js
2. Don't match on story, Storybook doesn't support that even if a user's glob pattern would match it. (Unless something changes recently in the default CSF Indexer that I'm unaware of)

[kasperpeulen]

Good point!

Regarding 2, do you know @shilman ?

[shilman]

Looks like we do support both suffixes in our indexer and the "." bug exists there too:

https://github.com/storybookjs/storybook/blob/next/code/core/src/core-server/presets/common-preset.ts#L191-L194