[feat] document on best practice of package.json for dual package (CJS+ESM)

[loynoir]

Suggestion

🔍 Search Terms

List of keywords you searched for before creating this issue. Write them down here so that others can find this suggestion more easily and help provide feedback.

• dual package CJS + ESM
• package.json best practice

✅ Viability Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

I fork a typescript CJS repo to add ESM support.

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sinclairzx81/typebox#400 (comment)

Do you have any reference links on best practice to support both ESM and CJS? I assume the cjs and esm submodule pathing is a common, but curious on best practice configuration of package.json. I had been meaning to support ESM, however probably as a minor semver, as internal directories have been changed.

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I use below config, seems working, but not sure if it is best practice.

Therefore, request for a official document.

https://github.com/loynoir/typebox/blob/feat-esm/package.json#L13-L56

==> cjs/package.json <==
{"type":"commonjs"}

==> esm/package.json <==
{"type":"module"}

📃 Motivating Example

💻 Use Cases

[MartinJohns]

Duplicate of #52593. You should mention your use case there, if it wasn't mentioned already (likely was).

[loynoir]

The issue behind this feat is #53949

dts resolve to CJS entry dts instead of ESM entry dts

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.