fix(plugin-legacy): ensure correct typing for node esm

[xiaoxiangmoe]

Description

According to https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-7.html#packagejson-exports-imports-and-self-referencing , the only way to correct provide types for both Node ESM and CJS is to have two separate declaration files, so we need to generate index.d.cts and index.d.mts.

unbuild@2 could generate index.d.cts and index.d.mts standing for types of index.cjs and index.mjs, and could generate index.d.ts for legacy typescript usage.

releated commit:
vuejs/core@d621d4c

releated PRs:
unjs/unbuild#273
vitejs/vite-plugin-vue#179

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the PR Title Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

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[patak-dev]

What is the reasoning behind removing this entry? We have the same setup on all other plugins: https://github.com/vitejs/vite-plugin-vue/blob/93c444cb99d64c65b71050d0f6a5e3016f7046a1/packages/plugin-vue/package.json#L14

[bluwy]

TypeScript is able to pick up the adjacent .ts by removing this, .e.g ./dist/index.mjs -> ./dist/index.d.mts. What this PR does is that it emits two dts files for the two formats :(

[antfu]

unjs/unbuild#273

Because of .d.mts and .d.cts, removing it will allow TS to find correct one by itself

[xiaoxiangmoe]

@patak-dev Here is also another PR https://github.com/vitejs/vite-plugin-vue/pull/179/files

[xiaoxiangmoe]

According to https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-7.html#packagejson-exports-imports-and-self-referencing , the only way to correct provide types for both Node ESM and CJS is to have two separate declaration files, so we need to generate index.d.cts and index.d.mts.

unbuild@2 could generate index.d.cts and index.d.mts standing for types of index.cjs and index.mjs, and could generate index.d.ts for legacy typescript usage.

releated commit:
vuejs/core@d621d4c

releated PRs:
unjs/unbuild#273
vitejs/vite-plugin-vue#179

[patak-dev]

I think this PR is good for plugins given our current setup. We could release it in a minor for the plugin. I added it to the 5.0 milestone (that we're going to start working on soon) because there is a parallel discussion about moving vite core and the plugins to ESM only. I still don't know if Vite 5 is the right major to do this, so if we don't move forward with that, we should merge this PR instead.
Polls that @bluwy started for reference:

• https://twitter.com/bluwyoo/status/1681341833581056001
• https://elk.zone/m.webtoo.ls/@bluwy/110736050873446169

[bluwy]

As much as I dislike this TS shenanigans, I'm ok to push this for the next plugin-legacy major for now, and drop CJS in the next-next major. I'm not sure if there's any migration paths we need to implement but I think we can cut right clean then.

@xiaoxiangmoe would you be able to upgrade unbuild to v2 stable and rebase the PR?

[bluwy]

Thanks!