Extension can't use plugin object (CLI can; Extension can use plugin's path/name string)

[tomchen]

Summary

Extension shows error while CLI is good with a local custom plugin.

Edit: it seems Extension can't use a imported plugin configuration object (but CLI can). Extension can only use plugin's path/name string

Steps To Reproduce:

• New folder, npm init -y, latest VS Code, install latest Prettier extension and set it as default JS formatter, prettier not installed globally with npm
• npm install -D prettier
• Add ./prettier.config.mjs:

import customPlugin from "./prettier-plugin-custom.mjs";

export default {
  plugins: [customPlugin],
};

• Add ./prettier-plugin-custom.mjs:

import { parsers as parsersBabel } from "prettier/plugins/babel";

export default {
  parsers: {
    babel: parsersBabel.babel,
  },
};

• npx prettier --write prettier-plugin-custom.mjs -> No problem
• Shift + Alt + F to format prettier-plugin-custom.mjs -> Error, log simply shows Invalid prettier configuration file detected. See log for details.

Additional information

VS Code Version:

Latest

Version: 1.98.0 (user setup)
Commit: 6609ac3d66f4eade5cf376d1cb76f13985724bcb
Date: 2025-03-04T21:06:18.612Z
Electron: 34.2.0
ElectronBuildId: 11044223
Chromium: 132.0.6834.196
Node.js: 20.18.2
V8: 13.2.152.36-electron.0
OS: Windows_NT x64 10.0.26100

Prettier Extension Version: Latest 11.0.0

OS and version: Windows 11

Prettier Log Output

Simply

Invalid prettier configuration file detected. See log for details.

I don't see any details

Further attempts

I changed Node.js from v22.13.1 to v20.18.2 with nvm to align with VS Code Electron's Node version to see if it is caused by that, but CLI is still good.

I changed the files to Common JS:

prettier.config.cjs

const customPlugin = require("./prettier-plugin-custom.cjs");

module.exports = {
  plugins: [customPlugin],
};

prettier-plugin-custom.cjs

const { parsers: parsersBabel } = require("prettier/parser-babel");

module.exports = {
  parsers: {
    babel: parsersBabel.babel,
  },
};

Still CLI good extension bad

[SystemParadox]

Invalid prettier configuration file detected. See log for details.

This is the most frustrating thing about this issue - there is no log that shows anything other than this message. Combined with the fact that it works fine on the command line it makes this completely impossible to debug.

[SystemParadox]

Help -> Toggle developer tools in vscode may be helpful. This at least lets me see console.log statements in the prettier file. In my case the prettierrc is loading fine, so I think it's something in prettier or this plugin that then throws for some reason?

Changing to use plugins: ['prettier-plugin-svelte'] rather than plugins: [ require('prettier-plugin-svelte') ] seems to fix it which is odd. Does prettier not allow loading plugins like this anymore? But then why does it work on the CLI?

[kingston]

It appears related to prettier/prettier#15167 so potentially something to do with RPC boundaries and the fact that required modules cannot be sent to the appropriate worker thread.

I was able to workaround it with:

import url from 'node:url';

export default {
  ...,
  plugins: [
    url.fileURLToPath(import.meta.resolve('prettier-plugin-packagejson')),
  ]
}

But the simple string works too if it's in the root node_modules (I'm using a monorepo approach with PNPM which does not hoist plugins by default anymore)

[SystemParadox]

We're also using pnpm but we've added public-hoist-pattern[]='prettier-plugin-svelte' to .npmrc to hoist it.

The fileURLToPath example is useful though, I might try that instead.

[tomchen]

OK. Updated the title and summary

[github-actions]

This issue has been labeled as stale due to inactivity. Reply to keep this issue open.

[SystemParadox]

Even if this isn't something that prettier-vscode can fix, it does at least need documenting.

[github-actions]

Stale Issue

This issue has been automatically marked as stale because it hasn't had any activity in 60 days.

What happens next:

• If no further activity occurs, this issue will be closed in 7 days
• To keep this issue open, add a comment or remove the stale label

If this issue is still relevant and you have new information to add, please comment below.

[ntotten]

This issue should be resolved in version 12 of the extension. Version 12 is currently in preview and is published only to the new Prettier organization. You can find that version here: https://marketplace.visualstudio.com/items?itemName=Prettier.prettier-vscode

Once we decide version 12 is stable it will be published to the old extension location as well.

Please test this issue in version 12 and let me know if this is still an issue. If we don't hear back this issue may be closed.