[Bug]: flat config crash when using manual plugin def and recommended config

[bradzacher]

Is there an existing issue for this?

• I have searched the existing issues and my issue is unique
• My issue appears in the command-line and not only in the text editor

Description Overview

Repro

// eslint.config.js
import eslintReact from 'eslint-plugin-react';
import eslintReactRecommended from 'eslint-plugin-react/configs/recommended.js';

export default [
	{
		plugins: {
			react: eslintReact,
		},
	},
	eslintReactRecommended,
];

npx eslint eslint.config.js

Expected

No errors

Actual

Oops! Something went wrong! :(

ESLint: 8.56.0

Error: Key "plugins": Cannot redefine plugin "react".

More Info

When defining a plugin key in the flat config ESLint enforces that you only ever redefine they key with the same plugin. This check is done by comparing by reference -- i.e. configA.plugin.react === configB.plugin.react

eslint-plugin-react fails this check because it defines its "plugin" in two locations:

eslint-plugin-react/index.js

Lines 14 to 31 in 36e791d

	module.exports = {
	deprecatedRules: configAll.plugins.react.deprecatedRules,
	rules: allRules,
	configs: {
	recommended: Object.assign({}, configRecommended, {
	parserOptions: configRecommended.languageOptions.parserOptions,
	plugins,
	}),
	all: Object.assign({}, configAll, {
	parserOptions: configAll.languageOptions.parserOptions,
	plugins,
	}),
	'jsx-runtime': Object.assign({}, configRuntime, {
	parserOptions: configRuntime.languageOptions.parserOptions,
	plugins,
	}),
	},
	};

eslint-plugin-react/configs/all.js

Lines 23 to 26 in 36e791d

	react: {
	deprecatedRules,
	rules: allRules,
	},

For this to work there needs to be exactly 1 copy of the "plugin" defined by the package.
For example:

const plugin = { ... };
plugin.configs = {
  recommended: {
    plugins: { react: plugin },
    rules: { ... },
  },
  all: {
    plugins: { react: plugin },
    rules: { ... },
  },
});

eslint-plugin-react version

v7.33.2

eslint version

v8.56.0

node version

v20.11.0

[me4502]

It's also worth noting that this affects using multiple configurations from this plugin too. It prevents using both the flat recommended and jsx-runtime configurations at the time time for example, which is the recommended configuration when using the React 17 JSX transform.

[ljharb]

@me4502 at the moment we don't support flat config at all, but indeed it needs to be fixed.

[michaelfaith]

I believe this is actually to do with the fact that the recommended config defines the plugin, and your config which uses the recommended config is also defining the plugin. It shouldn't have anything to do with plugins being defined in other places in the package. Can you try removing from your config?

{
  plugins: {
    react: eslintReact,
  },
},