eslint.config.mjs

import typescriptEslint from "@typescript-eslint/eslint-plugin";
import vitest from "eslint-plugin-vitest";
import { fixupConfigRules } from "@eslint/compat";
import tsParser from "@typescript-eslint/parser";
import path from "node:path";
import { fileURLToPath } from "node:url";
import js from "@eslint/js";
import { FlatCompat } from "@eslint/eslintrc";
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const compat = new FlatCompat({
    baseDirectory: __dirname,
    recommendedConfig: js.configs.recommended,
    allConfig: js.configs.all
});

export default [...fixupConfigRules(compat.extends(
    "plugin:react/jsx-runtime",
    "plugin:react-hooks/recommended",
    "plugin:promise/recommended",
    "plugin:@tanstack/eslint-plugin-query/recommended",
    "plugin:vitest/legacy-recommended",
    "plugin:@typescript-eslint/recommended-type-checked",
    "plugin:@cspell/recommended",
    "plugin:import-x/recommended",
    "plugin:import-x/typescript",
    "prettier",
)), {
    plugins: {
        "@typescript-eslint": typescriptEslint,
        vitest,
    },

    languageOptions: {
        parser: tsParser,
        ecmaVersion: 2022,
        sourceType: "module",

        parserOptions: {
            project: true,
        },
    },

    settings: {
        "import-x/resolver": {
            typescript: true,
            node: true,
        },
    },

    rules: {
        "react/react-in-jsx-scope": "off",
        "react/prop-types": "off",
        "react/require-default-props": "off",
        "react/jsx-props-no-spreading": "off",
        "no-shadow": "off",
        "@typescript-eslint/no-shadow": "error",
        "no-unused-vars": "off",
        "no-underscore-dangle": "off",

        "@typescript-eslint/no-unused-vars": ["warn", {
            varsIgnorePattern: "^React",
        }],

        "@typescript-eslint/no-explicit-any": "off",
        "@typescript-eslint/no-floating-promises": "off",
        "no-return-await": "off",
        "@typescript-eslint/require-await": "off",

        "@typescript-eslint/no-misused-promises": ["error", {
            checksVoidReturn: false,
        }],

        "jsx-a11y/label-has-associated-control": "off",
        "jsx-a11y/no-autofocus": "off",

        "react/jsx-filename-extension": [1, {
            extensions: [".js", ".jsx", ".ts", ".tsx", ".test.tsx"],
        }],

        "react/function-component-definition": "off",
        "no-console": "off",
        "react-hooks/exhaustive-deps": "error",
        "import-x/no-named-as-default": "off",
        "import-x/no-named-as-default-member": "off",
    },
}];

eslintrc.js

module.exports = {
  extends: [
    'plugin:react/jsx-runtime',
    'plugin:react-hooks/recommended',
    'plugin:promise/recommended',
    'plugin:@tanstack/eslint-plugin-query/recommended',
    'plugin:vitest/legacy-recommended',
    'plugin:@typescript-eslint/recommended-type-checked',
    'plugin:@cspell/recommended',
    'plugin:import-x/recommended',
    'plugin:import-x/typescript',
    'prettier',
  ],
  plugins: ['@typescript-eslint', 'vitest'],
  rules: {
    'react/react-in-jsx-scope': 'off',
    'react/prop-types': 'off',
    'react/require-default-props': 'off',
    'react/jsx-props-no-spreading': 'off',
    'no-shadow': 'off',
    '@typescript-eslint/no-shadow': 'error',
    'no-unused-vars': 'off',
    'no-underscore-dangle': 'off',
    '@typescript-eslint/no-unused-vars': [
      'warn',
      { varsIgnorePattern: '^React' },
    ],
    '@typescript-eslint/no-explicit-any': 'off',
    '@typescript-eslint/no-floating-promises': 'off',
    'no-return-await': 'off',
    '@typescript-eslint/require-await': 'off',
    '@typescript-eslint/no-misused-promises': [
      'error',
      {
        checksVoidReturn: false,
      },
    ],
    'jsx-a11y/label-has-associated-control': 'off',
    'jsx-a11y/no-autofocus': 'off',
    'react/jsx-filename-extension': [
      1,
      { extensions: ['.js', '.jsx', '.ts', '.tsx', '.test.tsx'] },
    ],
    'react/function-component-definition': 'off',
    'no-console': 'off',
    'react-hooks/exhaustive-deps': 'error',
    'import-x/no-named-as-default': 'off',
    'import-x/no-named-as-default-member': 'off',
  },
  settings: {
    'import-x/resolver': {
      typescript: true,
      node: true,
    },
  },
  parser: '@typescript-eslint/parser',
  parserOptions: {
    ecmaVersion: 2022,
    sourceType: 'module',
    project: true,
  },
};

gistfile1.txt

Errors:

ConfigError: Config (unnamed): Key "plugins": Cannot redefine plugin "vitest".
ConfigError: Config (unnamed): Key "plugins": Cannot redefine plugin "@typescript-eslint".