4.0.0 publishing is broken

[mfedderly]

Via https://publint.dev/rbush@4.0.0

When changing the package.json to "type": "module" all .js files will be interpreted as ESM, but rbush.js is still CJS. That leads to an issue where certain module resolution setups will result in issues, trying to interpret rbush.js as ESM. I believe this would be resolved by simply changing the filename to rbush.cjs instead.

This came up when I was trying to update the types to support 4.0.0 here: DefinitelyTyped/DefinitelyTyped#70340

[mourner]

I don't think it should be broken because according to the ESM docs, the exports field (which points to ESM entry point) supersedes the main field. However, I should probably have it pointed to the same entry point just in case some external tools like TS interpret this incorrectly.

[mfedderly]

I think older resolvers (Typescript in node10 mode) will still use main, unfortunately. That's what made the typings hard to make correct in DefinitelyTyped.

[mourner]

Should be fixed in 4.0.1.

[jakebailey]

I'm not sure that is the right fix... The old state was that exports always pointed to index.js, so ESM could import and CJS could dynamic import, with old non-type=module expecting things still being able to load from the main entrypoint (sort of unexpected). But now, both point to index.js, so they'll all fail.

rbush.js is what contains the CJS code (technically UMD), but by Node rules, that file will never acutally work due to its extension + type=module implying that it's ESM.

Is the intent that rbush.js must exist for back compat? Such that not using ESM in .js would be a better solution, and this can be written?

"exports": {
    ".": {
        "import": "./index.mjs",
        "require": "./rbush.js"
    }
}

Maybe?

[mourner]

@jakebailey no, my intent is not to support CommonJS at all. UMD rbush.js is there for the old <script>-based CDN use for the browsers, not for Node, which supports ESM on all maintained versions since a long time ago.

[jakebailey]

Ah, then you don't need to publish with the "main" field at all.