@mlaursen/eslint-config

eslint-config

A reusable eslint config that I use for most of my projects.

Starting at 5.0.0, I only support eslint@^9 or greater.

Installation

npm install -D eslint @mlaursen/eslint-config

Then create an eslint.config.mjs with the following:

// @ts-check
import { config, configs, gitignore } from "@mlaursen/eslint-config";

// choose the config you want to use:
// somewhat strict type checking
export default config(gitignore(import.meta.url), ...configs.frontend);

// strict type checking
export default config(gitignore(import.meta.url), ...configs.frontendTypeChecking(import.meta.dirname));

// NOTE: This is recommended for strict type checking. Callable as:
// `cross-env STRICT_TYPING=true eslint "**/*.{ts,tsx,mts,mtsx,js,jsx,mjs,cjs}`
//
// strict type checking with an environment variable. uncomment the following
// line to enable it in your editor
// const strict = true || process.env.STRICT_TYPING === 'true';
const strict = process.env.STRICT_TYPING === 'true';
const frontend = strict ? configs.frontendTypeChecking(import.meta.dirname) : configs.frontend
export default (gitignore(import.meta.url), ...frontend);

The config export is the typescript-eslint.config() function to provide type definitions and gitignore automatically ignores files from linting based on your .gitignore rules.

Configs

I normally just use the frontend or frontendTypeChecking configs, but the others can be used individually if needed.

• base
• typescript
• typescriptTypeChecking
• jest
• jestDom
• testingLibraryReact
• testingLibraryDom
• react
• jsxA11y
• next
• frontend
• frontendTypeChecking

base

The base config is automatically used by the typescript config and is just the eslint.configs.recommended and a few other stylistic changes.

This should not be used if the typescript or typescriptTypeChecking configs are used.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.base);

typescript

This extends the base config and the tseslint.configs.strict config. It also includes a few stylistic choices for type behavior and disabled strict rules in test files.

Only this rule or typescripttypechecking should be used. They should not be used together.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.typescript);

typescriptTypeChecking

This is the same as the typescript config but also includes the tseslint.configs.strictTypeCheckedOnly config.

Only this rule or typescript should be used. They should not be used together.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.typescriptTypeChecking(import.meta.dirname));

jest

This only enables the eslint-plugin-jest.configs['flat/recommended] rules on tests files.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.jest);

jestDom

This only enables the eslint-plugin-jest-dom.configs['flat/recommended] rules on tests files.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.jestDom);

testingLibraryReact

This enables the eslint-plugin-testing-library/.configs["flat/react] plugin and rules on test files.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.testingLibraryReact);

testingLibraryDom

This enables the eslint-plugin-testing-library/.configs["flat/dom] plugin and rules on test files.

This should not be used with the testingLibraryReact rules

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.testingLibraryDom);

react

This enables the eslint-plugin-react and eslint-plugin-react-hooks:

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.react);

jsxA11y

This enables eslint-plugin-jsx-a11y:

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.jsxA11y);

next

This is a small wrapper around the @next/eslint-plugin-next that works with eslint v9.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.next);

frontend

This is my normal frontend repo setup with react, jsxA11y, jest, jest-dom, typescript, testing-library/react.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.frontend);

frontendTypeChecking

Same as the frontend, but enables the strict type checking.

// @ts-check
import { config, configs } from "@mlaursen/eslint-config";

export default config(...configs.frontendTypeChecking(import.meta.dirname));

Changelog

5.2.0

Minor Changes

• Features:

  • bump dependencies to latest

  Fixes:

  • Disabled @typescript-eslint/unified-signatures since you get better type inference with separate signatures
  • Disabled no-undef and removed globals since I use typescript