--- name: migrate-oxlint description: Guide for migrating a project from ESLint to Oxlint. Use when asked to migrate, convert, or switch a JavaScript/TypeScript project's linter from ESLint to Oxlint. --- This skill guides you through migrating a JavaScript/TypeScript project from ESLint to [Oxlint](https://oxc.rs/docs/guide/usage/linter/). ## Overview Oxlint is a high-performance linter that implements many popular ESLint rules natively in Rust. It can be used alongside ESLint or as a full replacement. An official migration tool is available, and will be used by this skill: [`@oxlint/migrate`](https://github.com/oxc-project/oxlint-migrate) ## Step 1: Run Automated Migration Run the migration tool in the project root: ```bash npx @oxlint/migrate ``` This reads your ESLint flat config (`eslint.config.js` for example) and generates a `.oxlintrc.json` file from it. It will find your ESLint config file automatically in most cases. See options below for more info. ### Key Options | Option | Description | | --------------------------- | ------------------------------------------------------------------------------------------------------------------------------- | | `--type-aware` | Include type-aware rules from `@typescript-eslint` (will require the `oxlint-tsgolint` package to be installed after migrating) | | `--with-nursery` | Include experimental rules still under development, may not be fully stable or consistent with ESLint equivalents | | `--js-plugins [bool]` | Enable/disable ESLint plugin migration via `jsPlugins` (default: enabled) | | `--details` | List rules that could not be migrated | | `--replace-eslint-comments` | Convert all `// eslint-disable` comments to `// oxlint-disable` | | `--output-file ` | Specify a different output path (default: `.oxlintrc.json`) | If your ESLint config is not at the default location, pass the path explicitly: ```bash npx @oxlint/migrate ./path/to/eslint.config.js ``` ## Step 2: Review Generated Config After migration, review the generated `.oxlintrc.json`. ### Plugin Mapping The migration tool automatically maps ESLint plugins to oxlint's built-in equivalents. The following table is for reference when reviewing the generated config: | ESLint Plugin | Oxlint Plugin Name | | --------------------------------------------------- | ------------------ | | `@typescript-eslint/eslint-plugin` | `typescript` | | `eslint-plugin-react` / `eslint-plugin-react-hooks` | `react` | | `eslint-plugin-import` / `eslint-plugin-import-x` | `import` | | `eslint-plugin-unicorn` | `unicorn` | | `eslint-plugin-jsx-a11y` | `jsx-a11y` | | `eslint-plugin-react-perf` | `react-perf` | | `eslint-plugin-promise` | `promise` | | `eslint-plugin-jest` | `jest` | | `@vitest/eslint-plugin` | `vitest` | | `eslint-plugin-jsdoc` | `jsdoc` | | `eslint-plugin-next` | `nextjs` | | `eslint-plugin-node` | `node` | | `eslint-plugin-vue` | `vue` | Default plugins (enabled when `plugins` field is omitted): `unicorn`, `typescript`, `oxc`. Setting the `plugins` array explicitly overrides these defaults. ESLint core rules are usable in oxlint without needing to configure a plugin in the config file. ### Rule Categories Oxlint groups rules into categories for bulk configuration, though only `correctness` is enabled by default: ```json { "categories": { "correctness": "error", "suspicious": "warn" } } ``` Available categories: `correctness` (default: enabled), `suspicious`, `pedantic`, `perf`, `style`, `restriction`, `nursery`. Individual rule settings in `rules` override category settings. `@oxlint/migrate` will turn `correctness` off to avoid enabling additional rules that weren't enabled by your ESLint config. You can choose to enable additional categories after migration if desired. ### Check Unmigrated Rules Run with `--details` to see which ESLint rules could not be migrated: ```bash npx @oxlint/migrate --details ``` Review the output and decide whether to keep ESLint for those rules or not. Some rules may be mentioned in the output from `--details` as having equivalents in oxlint that were not automatically mapped by the migration tool. In those cases, consider enabling the equivalent oxlint rule manually after migration. ## Step 3: Install Oxlint Install the core oxlint package (use `yarn install`, `pnpm install`, `vp install`, `bun install`, etc. depending on your package manager): ```bash npm install -D oxlint ``` If you want to add the `oxlint-tsgolint` package, if you intend to use type-aware rules that require TypeScript type information: ```bash npm install -D oxlint-tsgolint ``` No other packages besides the above are needed by default, though you will need to keep/install any additional ESLint plugins that were migrated into `jsPlugins`. Do not add `@oxlint/migrate` to the package.json, it is meant for one-off usage. ## Step 4: Handle Unsupported Features Some features require manual attention: - Local plugins (relative path imports): Must be migrated manually to `jsPlugins` - `eslint-plugin-prettier`: Supported, but very slow. It is recommended to use [oxfmt](https://oxc.rs/docs/guide/usage/formatter) instead, or switch to `prettier --check` as a separate step alongside oxlint. - `settings` in override configs: Oxlint does not support `settings` inside `overrides` blocks. - ESLint v9+ plugins: Not all work with oxlint's JS Plugins API, but the majority will. ### Local Plugins If you have any custom ESLint rules in the project repo itself, you can migrate them manually after running the migration tool by adding them to the `jsPlugins` field in `.oxlintrc.json`: ```json { "jsPlugins": ["./path/to/my-plugin.js"], "rules": { "local-plugin/rule-name": "error" } } ``` ### External ESLint Plugins For ESLint plugins without a built-in oxlint equivalent, use the `jsPlugins` field to load them: ```json { "jsPlugins": ["eslint-plugin-custom"], "rules": { "custom/my-rule": "warn" } } ``` ## Step 5: Update CI and Scripts Replace ESLint commands with oxlint. Path arguments are optional; oxlint defaults to the current working directory. ```bash # Before npx eslint src/ npx eslint --fix src/ # After npx oxlint src/ npx oxlint --fix src/ ``` ### Common CLI Options | ESLint | oxlint equivalent | | ------------------------- | ---------------------------------------------- | | `eslint .` | `oxlint` (default: lints the cwd) | | `eslint src/` | `oxlint src/` | | `eslint --fix` | `oxlint --fix` | | `eslint --max-warnings 0` | `oxlint --deny-warnings` or `--max-warnings 0` | | `eslint --format json` | `oxlint --format json` | Additional oxlint options: - `--tsconfig `: Specify tsconfig.json path, likely unnecessary unless you have a non-standard name for `tsconfig.json`. ## Tips - You can run alongside ESLint if necessary: Oxlint is designed to complement ESLint during migration, but with JS Plugins many projects can switch over fully without losing many rules. - Disable comments work: `// eslint-disable` and `// eslint-disable-next-line` comments are supported by oxlint. Use `--replace-eslint-comments` when running @oxlint/migrate to convert them to `// oxlint-disable` equivalents if desired. - List available rules: Run `npx oxlint --rules` to see all supported rules, or refer to the [rule documentation](https://oxc.rs/docs/guide/usage/linter/rules.html). - Schema support: Add `"$schema": "./node_modules/oxlint/configuration_schema.json"` to `.oxlintrc.json` for editor autocompletion if the migration tool didn't do it automatically. - Output formats: `default`, `stylish`, `json`, `github`, `gitlab`, `junit`, `checkstyle`, `unix` - Ignore files: `.eslintignore` is supported by oxlint if you have it, but it's recommended to move any ignore patterns into the `ignorePatterns` field in `.oxlintrc.json` for consistency and simplicity. All files and paths ignored via a `.gitignore` file will be ignored by oxlint by default as well. - If you ran the migration tool multiple times, remove the `.oxlintrc.json.bak` backup file created by the migration tool once you've finished migrating. - If you are not using any JS Plugins and have replaced your ESLint configuration, you can remove all ESLint packages from your project dependencies. - Ensure your editor is configured to use oxlint instead of ESLint for linting and error reporting. You may want to install the Oxc extension for your preferred editor. See https://oxc.rs/docs/guide/usage/linter/editors.html for more details. ## References - [CLI Reference](https://oxc.rs/docs/guide/usage/linter/cli.html) - [Config File Reference](https://oxc.rs/docs/guide/usage/linter/config-file-reference.html) - [Complete Oxlint rule list and docs](https://oxc.rs/docs/guide/usage/linter/rules.html)