@jsimck/eslint-config

An extensible shared ESLint configuration. Comes pre-configured with Prettier, opinionated rules for JavaScript, TypeScript projects including React, Next.JS, jest eslint plugins and more.

The config uses new flat config format, which is supported by eslint 7.0.0 and above. This allows us to use .mjs extension and import other configs from npm packages.

Base config includes configurations for multiple frameworks (JS, TS, React, jest, import formatting) with some additional configs, you can use to extend the default one (see section below).

Install

pnpm add -D eslint@8 @jsimck/eslint-config

 We are currently stuck on eslint v8 until all of the config dependencies are compatible with new v9

Usage

Create eslint.config.mjs in the root of your directory with following contents:

import baseConfig from '@jsimck/eslint-config';

export default [...baseConfig];

Running eslint

Below is simple code snippet you can add to your package.json to run eslint:

{
  "scripts": {
    "lint": "ESLINT_USE_FLAT_CONFIG=true eslint -c eslint.config.mjs './**/*.{js,ts,jsx,tsx,cjs,mjs}'",
    "lint:fix": "pnpm lint --fix",
  }
}

Configs

Each config is a separate file, which can be imported and used in your config. For example, to use Next.JS config, you can do:

import baseConfig from '@jsimck/eslint-config';
import { next } from '@jsimck/eslint-config/configs';

export default [...baseConfig, ...next];

Check following table for all aviailable configs:

Config name	Description	Included in default config
base	Base config, includes language settings, globals, parser options	✅
javascript	Extends eslint recommended settings with some custom overrides	✅
imprt	eslint-plugin-import-x	✅
sortClassMembers	eslint-plugin-sort-class-members	✅
unusedImports	eslint-plugin-unused-imports	✅
unicorn	eslint-plugin-unicorn	✅
prettier	plugin:prettier/recommended	✅
react	eslint-plugin-react, eslint-plugin-react-hooks	✅
typescript	@typescript-eslint/eslint-plugin	✅
jest	eslint-plugin-jest, eslint-plugin-jest-formatting	❌
typescriptTypeChecked	Enables type-checking and type-checked rules (impacts performance)	❌
next	@next/eslint-plugin-next	❌

FAQ

Q: Does this work with VSCode eslint plugin?

A: Yes, due to flat config and (.mjs) extension, you have to enable some settings:

{
  "eslint.experimental.useFlatConfig": true,
  "eslint.options": {
    "overrideConfigFile": "eslint.config.mjs"
  },
}

Contribution guide

Every PR implementing new feature should include changeset. Use pnpm changeset from the root of the repository to generate new changeset and include it with your PR.

Release

Make sure all new features are merged to main and you are on main branch including their changesets. and run:

pnpm release

RC Versions

To enter RC mode, run:

pnpm release:rc:enter

when in RC mode, all version releases will have -rc suffix. To exit RC mode, run:

pnpm release:rc:exit