[locale] Split locales into separate files

[christopherschroer]

• I have followed (at least) the PR section of the contributing guide.

This non-breaking PR splits the single giant locale file found here into individual files for each locale.

Benefits:

• aligns with locale setups in MUI-X packages
• easier to quickly identify which locales are supported
• easier to include only locales that are desired in app bundles
• easier to dynamically import individual locales

[alexfauquette]

The PR looks ok to me. I let core team check this does nto imply a breaking change

@LukasTy From what I remeber you had to do an extra effort to get

easier to include only locales that are desired in app bundles

[LukasTy]

I feel like it would be simpler to replace these lines with immediate named exports and then use the same re-exporting strategy as in: https://github.com/mui/mui-x/blob/master/packages/x-date-pickers/src/locales/index.ts
WDYT?

Suggested change

	const amET: Localization = {
	export const amET: Localization = {

[christopherschroer]

@LukasTy I tried that approach originally, but ESLint got mad. It is currently configured to prefer default export on a file with one export. How should I proceed?

[LukasTy]

You can add an exclusion to disable this rule on packages/mui-material/src/locale/* alongside this:

material-ui/eslint.config.mjs

Lines 249 to 255 in 6afef27

	// Migrated config from packages/api-docs-builder/.eslintrc.js
	{
	files: ['packages/api-docs-builder/**/*'],
	rules: {
	'import/prefer-default-export': 'off',
	},
	},

Unless there is a clear objection from @mui/material-ui? 🤔

[christopherschroer]

@LukasTy I have made the recommended changes

[LukasTy]

Great work, LGTM. 👍
But I'd still like to see approval from someone more actively maintaining this repo. 🤔

P.S. @christopherschroer could you please run pnpm prettier and commit the fixes? 🙏

[mui-bot]

Netlify deploy preview

https://deploy-preview-46933--material-ui.netlify.app/

Bundle size report

Bundle	Parsed size	Gzip size
@mui/material	0B(0.00%)	0B(0.00%)
@mui/lab	0B(0.00%)	0B(0.00%)
@mui/system	0B(0.00%)	0B(0.00%)
@mui/utils	0B(0.00%)	0B(0.00%)

Details of bundle changes

Generated by 🚫 dangerJS against 3d7f4cf

[christopherschroer]

Great work, LGTM. 👍 But I'd still like to see approval from someone more actively maintaining this repo. 🤔

P.S. @christopherschroer could you please run pnpm prettier and commit the fixes? 🙏

Done

[siriwatknp]

easier to include only locales that are desired in app bundles
easier to dynamically import individual locales

Can you elaborate on this?

I think this PR would help the development because a single file is loaded instead of the whole localization but for production it should be the same because of tree-shaking.

For "dynamically import individual locales", I don't think it's possible with dynamic('@mui/material/locale/zhCN') due to the current package json exports is it? cc @Janpot

[christopherschroer]

@siriwatknp You are correct about my first claim. However when using a bundle analyzer, having a monolithic locale file makes it harder to determine which locales are being included.

As for the second claim, you can dynamically import locales from MUI by creating individual locale files in your project that simply re-export the applicable locale from MUI and then lazy loading your project's locale files. It's not the slickest way of doing it by far, but it works with how MUI exports everything. It's how I dynamically loaded the locales from MUI-X

[LukasTy]

Thank you for the comments.
Since there are no raised concerns, I'm merging this PR. 👌
Once again, @christopherschroer, your contribution is appreciated. 🙏