[Bug?]: ESLint extension doesn't work with yarn pnp - Error: Missing "./lib/api.js" export in "eslint" package

[NixBiks]

Self-service

• I'd be willing to implement a fix

Describe the bug

I'm using the ESLint extension in VSCode. Unfortunately it doesn't work with Plug'n'Play - according to the docs it should work if I understand correctly?

I've been looking at issues both here and in the ESLint extension repro but I haven't found anyone with this exact error it seems. I'm not sure if the issue belongs here or in the ESLint extension repro, let me know.

To reproduce

Make sure you have arcanis.vscode-zipfs and dbaeumer.vscode-eslint extensions installed in VS Code.

Run the following commands and just select defaults in the config initialization wizard

mkdir eslint-test
cd eslint-test
yarn set version berry
yarn init
yarn add -D eslint
yarn dlx @yarnpkg/sdks vscode
yarn eslint --init

Now verify that eslint will highlight an error in .eslintrc.js when running the following command (as expected)

yarn eslint .

Open eslintrc.js in VS Code and verify that the ESLint extension doesn't work. You can select the Output tab and select ESLint in the dropdown and see the following error

[Error - 2:16:22 PM] Error: Missing "./lib/api.js" export in "eslint" package
Require stack:
- /home/nixd/Projects/eslint-test/.pnp.cjs
    at bail (/home/nixd/Projects/eslint-test/.pnp.cjs:10700:8)
    at resolve (/home/nixd/Projects/eslint-test/.pnp.cjs:10776:10)
    at applyNodeExportsResolution (/home/nixd/Projects/eslint-test/.pnp.cjs:11027:28)
    at resolveUnqualifiedExport (/home/nixd/Projects/eslint-test/.pnp.cjs:11540:35)
    at resolveRequest (/home/nixd/Projects/eslint-test/.pnp.cjs:11606:99)
    at Object.resolveRequest (/home/nixd/Projects/eslint-test/.pnp.cjs:11681:26)
    at Function.external_module_.Module._resolveFilename (/home/nixd/Projects/eslint-test/.pnp.cjs:10533:34)
    at Function.external_module_.Module._load (/home/nixd/Projects/eslint-test/.pnp.cjs:10355:48)
    at Module.require (internal/modules/cjs/loader.js:1006:19)
    at require (internal/modules/cjs/helpers.js:88:18)
[Error - 2:20:20 PM] Error: Missing "./lib/api.js" export in "eslint" package

Environment

System:
    OS: Linux 5.11 Ubuntu 20.04.3 LTS (Focal Fossa)
    CPU: (24) x64 AMD Ryzen 9 3900X 12-Core Processor
  Binaries:
    Node: 15.14.0 - /tmp/xfs-affdb263/node
    Yarn: 3.0.2 - /tmp/xfs-affdb263/yarn
    npm: 7.24.1 - ~/.nvm/versions/node/v15.14.0/bin/npm

Additional context

No response

[joelmukuthu]

Hi @mr-bjerre I just experienced the same issue. This is specifically an error with ESLint v8 and is caused by https://eslint.org/docs/8.0.0/user-guide/migrating-to-8.0.0#the-lib-entrypoint-has-been-removed.

Before it's fixed here, you can workaround it by updating your ESLint SDK file (.yarn/sdks/eslint/lib/api.js). Change the export from:

// Defer to the real eslint your application uses
module.exports = absRequire(`eslint/lib/api.js`);

To:

// Defer to the real eslint your application uses
module.exports = absRequire(`eslint`);

[NixBiks]

Cool @joelmukuthu .

I agree that the workaround doesn't throw the error anymore but the extension doesn't seem to highlight any issues either. So it isn't really working...

EDIT

This is related to microsoft/vscode-eslint#1225

[arcanis]

Hm but why is vscode-eslint reading in ./lib/api.js? I don't find which part of the extension does it 🤔

[joelmukuthu]

@arcanis it seems that OP ran into a different issue that's related to vscode-eslint :)

The original issue is caused by code in the ESLint SDKs for VS Code that are generated by Yarn. I'm not sure but it looks like this is what causes it:

berry/packages/yarnpkg-sdks/sources/sdks/vscode.ts

Line 37 in d004727

`lib/api.js` as PortablePath,

Perhaps changing that to an empty string would fix it? 😃 And not to complicate this, but it might also be worthwhile to update how the SDKs are generated; in essence, to remove direct imports of "internal" module files

[vinassefranche]

Hello! I see this has the label good first issue I'd be willing to work on it to understand better how this work and help fix this issue. I have no idea how the sdk code is generated though. Is there any documentation available to start looking at this on my own? Are there any hint on where to start digging?

Thanks in advance for your answers!

[merceyz]

This was fixed in #3709 but we forgot to reference this issue

yarn dlx @yarnpkg/sdks

[vinassefranche]

@merceyz thanks for the info! Don't hesitate to ping me if you see something I can help on!