Using eslint-config-airbnb with ESLint v9

eslint.config.mjs

/*
 * To install `eslint-config-airbnb`, run:
 * npm install -D eslint-config-airbnb --force
 *
 * The --force flag is necessary because `eslint-config-airbnb` has a
 * peer dependency on `eslint@^8.0.0`, which may conflict with other
 * packages in your project.
 * 
 * After installing, you'll need to use `npm install --force` when
 * installing other packages to avoid conflicts with the peer dependencies.
 */

import js from "@eslint/js";
import { defineConfig } from "eslint/config";
import { FlatCompat } from "@eslint/eslintrc";
import { fileURLToPath } from "node:url";
import path from "node:path";

// mimic CommonJS variables -- not needed if using CommonJS
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

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

export default defineConfig([
  {
    files: ["**/*.{js,mjs,cjs}"],
    extends: [compat.extends("airbnb")]
  },
]);