@eslint/migrate-config

# ESLint Configuration Migrator ## Overview This package aids in the migration of the legacy ESLint configuration file format (`.eslintrc.`) to the new ESLint configuration file format (`eslint.config.js`). **Note:** The generated configuration file isn't guaranteed to work in all cases, but it should get you a lot closer to a working configuration file than manually trying to migrate. ## Limitations This tool currently works well for the following config file formats: - `.eslintrc` - `.eslintrc.json` - `.eslintrc.yml` If you are using a JavaScript configuration file (`.eslintrc.js`, `.eslintrc.cjs`, `.eslintrc.mjs`), this tool currently is only capable of migrating the _evaluated_ configuration. That means any logic you may have inside of the file will be lost. If your configuration file is mostly static, then you'll get a good result; if your configuration file is more complex (using functions, calculating paths, etc.) then this tool will not provide an equivalent configuration file. ## Usage You can run this package on the command line without installing it first by using `npx` or a similar tool: ```shell npx @eslint/migrate-config .eslintrc.json # or bunx @eslint/migrate-config .eslintrc.json ``` The tool will automatically find your `.eslintignore` file in the same directory and migrate that into your new configuration file. If you receive any npm errors while running using `npx`, install the package manually first: ```shell npm i @eslint/migrate-config npx @eslint/migrate-config .eslintrc.json ``` ### CommonJS Output By default, this tool generates an ESM file (`.mjs` extension). If you'd like to generate a CommonJS file instead, pass the `--commonjs` flag: ```shell npx @eslint/migrate-config .eslintrc.json --commonjs # or bunx @eslint/migrate-config .eslintrc.json --commonjs ``` ### Including a `.gitignore` file If you are currently using `--ignore-path .gitignore` on the CLI, you'll need to read the `.gitignore` file into your config file. The migration can handle this for you by passing the `--gitignore` flag: ```shell npx @eslint/migrate-config .eslintrc.json --gitignore # or bunx @eslint/migrate-config .eslintrc.json --gitignore ``` ## Followup Steps Once you have completed the migration, you may need to manually modify the resulting config file. ### Upgrade Plugins and Double-Check Compatibility For any plugins used in your configuration file, make sure to upgrade to the latest version. Many plugins are creating their v9-compatible versions and this tool may be out-of-date in relation to which plugins fully support v9. After upgrading, double-check if the plugin still needs any of the compatibility utilities that were autogenerated as part of the migration. ### `--ext` If you are using `--ext` on the command line, such as: ```shell npx eslint --ext .ts . ``` You'll need to remove the `--ext` from the command line and add an equivalent object into your configuration file. For example, `--ext .ts` requires an object like this in your configuration file: ```js export default [ { files: ["**/*.ts"], }, // the rest of your config ]; ``` This tells ESLint to search for all files ending with `.ts` when a directory is passed on the command line. You can choose to add additional properties to this object if you'd like, but it's not required. ## License Apache 2.0   ## Sponsors The following companies, organizations, and individuals support ESLint's ongoing maintenance and development. [Become a Sponsor](https://eslint.org/donate) to get your logo on our READMEs and [website](https://eslint.org/sponsors). <h3>Platinum Sponsors</h3> <p><a href="https://automattic.com"><img src="https://images.opencollective.com/automattic/d0ef3e1/logo.png" alt="Automattic" height="128"></a></p><h3>Gold Sponsors</h3> <p><a href="https://qlty.sh/"><img src="https://images.opencollective.com/qltysh/33d157d/logo.png" alt="Qlty Software" height="96"></a></p><h3>Silver Sponsors</h3> <p><a href="https://vite.dev/"><img src="https://images.opencollective.com/vite/d472863/logo.png" alt="Vite" height="64"></a> <a href="https://liftoff.io/"><img src="https://images.opencollective.com/liftoff/2d6c3b6/logo.png" alt="Liftoff" height="64"></a> <a href="https://stackblitz.com"><img src="https://avatars.githubusercontent.com/u/28635252" alt="StackBlitz" height="64"></a></p><h3>Bronze Sponsors</h3> <p><a href="https://cybozu.co.jp/"><img src="https://images.opencollective.com/cybozu/933e46d/logo.png" alt="Cybozu" height="32"></a> <a href="https://opensource.sap.com"><img src="https://avatars.githubusercontent.com/u/2531208" alt="SAP" height="32"></a> <a href="https://www.crawljobs.com/"><img src="https://images.opencollective.com/crawljobs-poland/fa43a17/logo.png" alt="CrawlJobs" height="32"></a> <a href="https://depot.dev"><img src="https://images.opencollective.com/depot/39125a1/logo.png" alt="Depot" height="32"></a> <a href="https://icons8.com/"><img src="https://images.opencollective.com/icons8/7fa1641/logo.png" alt="Icons8" height="32"></a> <a href="https://discord.com"><img src="https://images.opencollective.com/discordapp/f9645d9/logo.png" alt="Discord" height="32"></a> <a href="https://www.gitbook.com"><img src="https://avatars.githubusercontent.com/u/7111340" alt="GitBook" height="32"></a> <a href="https://herocoders.com"><img src="https://avatars.githubusercontent.com/u/37549774" alt="HeroCoders" height="32"></a> <a href="https://citadel.co.jp"><img src="https://avatars.githubusercontent.com/u/75781367" alt="Citadel AI" height="32"></a> <a href="https://www.lambdatest.com"><img src="https://avatars.githubusercontent.com/u/171592363" alt="TestMu AI Open Source Office (Formerly LambdaTest)" height="32"></a></p> <h3>Technology Sponsors</h3> Technology sponsors allow us to use their products and services for free as part of a contribution to the open source ecosystem and our work. <p><a href="https://netlify.com"><img src="https://raw.githubusercontent.com/eslint/eslint.org/main/src/assets/images/techsponsors/netlify-icon.svg" alt="Netlify" height="32"></a> <a href="https://algolia.com"><img src="https://raw.githubusercontent.com/eslint/eslint.org/main/src/assets/images/techsponsors/algolia-icon.svg" alt="Algolia" height="32"></a> <a href="https://1password.com"><img src="https://raw.githubusercontent.com/eslint/eslint.org/main/src/assets/images/techsponsors/1password-icon.svg" alt="1Password" height="32"></a></p>