Core: Replace preset-env polyfills with babel-polyfills

[43081j]

Issue: #11255.

Another attempt, this time it depends on babel/babel-polyfills#40

presumably what they will want us to do is use the babel-polyfills plugin rather than the preset-env corejs config. the docs seem to suggest thats the way forward, so this is just a draft of doing it that way

[nicolo-ribaudo]

presumably what they will want us to do is use the babel-polyfills plugin rather than the preset-env corejs config

Yes, this will be the recommended way starting from Babel 8 👍

I want to add that even if this package's version is currently 0.0.6, it passes all the core-js tests we have in @babel/preset-env. The only reason for a 0.0.x version is that we'll release it as stable and officially make everyone migrate only once we release Babel 8.

The way you migrate to the new plugin in this PR is correct.

[43081j]

awesome, thanks for taking time to explain that.

and from what i can gather, setting the new flag to true means the paths are resolved from the cwd?

[nicolo-ribaudo]

and from what i can gather, setting the new flag to true means the paths are resolved from the cwd?

It is relative to the config file where storybook's preset is enabled, or to cwd if the preset is enabled in the programmatic options.

I don't know how you enable this preset, but maybe it would be better to:

• Add core-js as a dependency to Storybook
• Use absoluteImports: require.resolve("core-js"), so that it always resolves Storybook's core-js dependency.

[43081j]

yeah thats a good idea i think.

we already have core-js as a dependency but should probably resolve to it here rather than leave it up to babel. ill change it

[merceyz]

Should be fine to remove core-js as a dependency in the e2e tests now
ref

storybook/scripts/run-e2e-config.ts

Lines 168 to 169 in 6a3bf80

	// TODO: remove when https://github.com/storybookjs/storybook/issues/11255 is solved
	'core-js',

[43081j]

done.

also i noticed almost every package we have has a core-js dependency. are they still needed?

[43081j]

@nicolo-ribaudo do we have any timeline for when the merged pr in babel-polyfills will be published? just so i know to keep an eye on it if its soon. or if you could let me know in here when it is, that'd be super useful

[nicolo-ribaudo]

I'm updating some deps and then I'll release.

[nicolo-ribaudo]

Released

[43081j]

great, thanks for the quick turnaround on that :D

have pushed the updated one here too

[43081j]

i have tried this in two test repos:

• one where core-js@2 is a top level dependency, currently broken with storybook master
• one where core-js@3 is a top level dependency, currently works with master

with this branch, both worked fine! maybe we have fixed it finally? 😂

[43081j]

i do still need to know if all the sub-packages can drop the corejs dependency too.

pretty much every package we have has a corejs dependency in their package.json (every app/, addon/, etc).

[merceyz]

also i noticed almost every package we have has a core-js dependency. are they still needed?

Depends if they actually use it or if it was a workaround to get it to work before this PR

[merceyz]

The packages that are transpiled before publish will need to declare core-js as a dependency still, so that probably needs to be reverted

[ndelangen]

@shilman let's merge?

[merceyz]

PnP is happy so LGTM 👍

[shilman]

@ndelangen I'm going to make the cut over to 6.2 on Monday. Will merge then.

[merceyz]

Need to remove useBuiltIns: 'usage', corejs: '3' from here as well

storybook/lib/core/src/server/common/es6Transpiler.ts

Line 18 in 3239d25

{ shippedProposals: true, useBuiltIns: 'usage', corejs: '3' },

[ndelangen]

👏