[Bug?]: esbuild-plugin-pnp doesn't use module in package.json for libraries

[huvber]

Describe the bug

Even if in the building options of esbuild it's define module in the mainFields the plugin use always (and only main). This will create some problem because when building in esm or iife usually library put the umd (or commonjs) version in main and the esm one in modules.

To reproduce

One of the library that has this configuration in the package.json is swr
The following file can help to make a use case test

esbuild.js

const { pnpPlugin } = require('@yarnpkg/esbuild-plugin-pnp');
const esbuild = require('esbuild');

esbuild.build({
  entryPoints: {
    index: 'src/index.tsx',
    'index.html': 'src/index.html',
  },
  assetNames: '[name]',
  inject: ['./react-shim.js'],
  mainFields: ['module', 'main'],
  bundle: true,
  outdir: 'build',
  loader: {
    '.html': 'file',
    '.css': 'css',
  },
  plugins: [
    pnpPlugin(),
  ],
});

src/index.ts

import { render } from 'react-dom';
import useSWR from 'swr';

const App = () => {
  const result = useSWR('https://official-joke-api.appspot.com/random_joke');
  return (
    <section>
      <header>
        <h2>This is a test</h2>
      </header>
      <main>{result.data}</main>
    </section>
  );
};

render(<App />, document.querySelector('main'));

package.json

{
  "name": "esbuild-test",
  "sideEffects": false,
  "main": "build/index.js",
  "files": [
    "build"
  ],
  "scripts": {
    "build": "rm -rf build && yarn node esbuild.js"
  },
  "devDependencies": {
    "@types/react": "^17.0.13",
    "@types/react-dom": "^17",
    "@yarnpkg/esbuild-plugin-pnp": "^1.0.0-rc.13",
    "esbuild": "^0.12.16"
  },
  "dependencies": {
    "react": "^17.0.2",
    "react-dom": "^17.0.2",
    "swr": "^0.5.6"
  }
}

Environment

OS: macOS
browser: chrome, firefox

Additional context

No response

[huvber]

Can you please take a look at this? I think it will be a problem for a lot of projects

[yarnbot]

Hi! 👋

This issue looks stale, and doesn't feature the reproducible label - which implies that you didn't provide a working reproduction using Sherlock. As a result, it'll be closed in a few days unless a maintainer explicitly vouches for it or you edit your first post to include a formal reproduction (you can use the playground for that).

Note that we require Sherlock reproductions for long-lived issues (rather than standalone git repositories or similar) because we're a small team. Sherlock gives us the ability to check which bugs are still affecting the master branch at any given point, and decreases the amount of code we need to run on our own machines (thus leading to faster bug resolutions). It helps us help you! 😃

If you absolutely cannot reproduce a bug on Sherlock (for example because it's a Windows-only issue), a maintainer will have to manually add the upholded label. Thanks for helping us triaging our repository! 🌟

[KrysKruk]

To workaround this bug I used the extensions config. In my case I couldn't bundle the estree-walker package which in the package.json contains only module, not main. module points to src/index.js so I added it to the extensions list.

    plugins: [pnpPlugin({
      extensions: ['.tsx', '.ts', '.jsx', '.mjs', '.cjs', '.js', '.css', '.json', 'src/index.js']
    })],

This is a temporary fix. I believe there will be more packages like that, so the bug is still valid.

[swandir]

Related issue and an alternative workaround #2987 (comment)

[merceyz]

Native support for PnP was added to esbuild@0.15.0 so @yarnpkg/esbuild-plugin-pnp is no longer required and is getting deprecated, if you experience any issues with the PnP support in esbuild please report them upstream.