Support eslint flat config

[silverwind]

Likely depends on import-js#2556 but it's good to track nonetheless.

Ref: eslint/eslint#18093

[JounQin]

eslint-plugin-i is now eslint-plugin-import-x.

I'm focusing on TypeScript migration first, see also #41.

After that, I'll start working on new features like supporting flat config.

[meteorlxy]

Just to mention, some rules will break when using flat config. See this comment

In brief, eslint will fail to use eslint.config.js as config file after enabling import/no-unused-modules with unusedExports: true

Related issues:

• Bug: can not find flat file config eslint/eslint#16485
• import/no-unused-modules breaks --no-eslintrc and eslint fails import-js/eslint-plugin-import#2907
• Add note(s) to docs about flat configs and/or no-unused-modules' unusedExports not being supported in flat configs import-js/eslint-plugin-import#2964

[karlhorky]

Interesting, we are using eslint-plugin-import-x now with the Flat Config:

• Support eslint v9 import-js/eslint-plugin-import#2948 (comment)

This seems to be working for us so far:

• upleveled/eslint-config-upleveled@3115d7e (#369)

Simplified version of the code:

import eslintImportX from 'eslint-plugin-import-x';

/** @type {import('@typescript-eslint/utils/ts-eslint').FlatConfig.ConfigArray} */
const configArray = [
  {
    plugins: {
     'import-x': eslintImportX,
    },
    settings: {
      'import-x/parsers': {
        '@typescript-eslint/parser': ['.ts', '.tsx'],
      },
      'import-x/resolver': {
        // Load <rootdir>/tsconfig.json
        typescript: true,
        node: true,
      },
    },
    rules: {
      // Error on imports that don't match the underlying file system
      // https://github.com/un-ts/eslint-plugin-import-x/blob/master/docs/rules/no-unresolved.md
      'import-x/no-unresolved': 'error',
  },
];

[Zamiell]

@karlhorky I am trying out this plugin with the flat config. I copy pasted the config from your post, but I get these errors:

(I enabled more rules than simply import-x/no-unresolved.)

Any idea on how to fix?

[n0099]

module.exports = {
    extends: [
        'plugin:import-x/recommended',
        'plugin:import-x/typescript',
    ],
}

can only be translate into

export default [
    ...compat.config(pluginImportX.configs.recommended), // https://github.com/un-ts/eslint-plugin-import-x/issues/29#issuecomment-2148843214
    pluginImportX.configs.typescript, // no need of wrapping in compat.config() since there's no pluginImportX.configs.typescript.plugins
];

since

eslint-plugin-import-x/src/config/recommended.ts

Line 7 in 3abe5e4

plugins: ['import-x'],

is still passing string as plugin.

[onx2]

@n0099 where is compat coming from?

Is there an example of a simple flat config for eslint v9 that uses this plugin?

My super simple set up works for everything but the import sorting.

import globals from "globals";
import pluginJs from "@eslint/js";
import tseslint from "typescript-eslint";
import pluginImportX from "eslint-plugin-import-x";

export default [
  {
    languageOptions: { globals: globals.browser },
    ignores: ["./dist/"],
  },
  pluginJs.configs.recommended,
  ...tseslint.configs.recommended,
  pluginImportX.configs.typescript,
];

[n0099]

@n0099 where is compat coming from?

@eslint/eslintrc ota-meshi/typescript-eslint-parser-for-extra-files#95 (comment)

import { FlatCompat } from '@eslint/eslintrc';

My super simple set up works for everything but the import sorting.

If you only want to extends from typescript rules, the plugin is not defined in the rule:

eslint-plugin-import-x/src/config/typescript.ts

Lines 16 to 35 in 3abe5e4

	export = {
	settings: {
	'import-x/extensions': allExtensions,
	'import-x/external-module-folders': ['node_modules', 'node_modules/@types'],
	'import-x/parsers': {
	'@typescript-eslint/parser': [...typeScriptExtensions, '.cts', '.mts'],
	},
	'import-x/resolver': {
	node: {
	extensions: allExtensions,
	},
	},
	},
	rules: {
	// analysis/correctness
	// TypeScript compilation already ensures that named imports exist in the referenced module
	'import-x/named': 'off',
	},
	} satisfies PluginConfig

so manually add plugin define to let eslint know where to find defines for rule with prefix import-x/

+  { plugins: { 'import-x': pluginImportX } },
  pluginImportX.configs.typescript,

or just also extending recommended rules:

+  ...compat.config(pluginImportX.configs.recommended),
  pluginImportX.configs.typescript,