eslint-plugin-unicorn

64.0.0 verified Sat Apr 25 auth: no javascript

An ESLint plugin providing over 100 powerful lint rules focused on best practices, consistency, and code quality. Current stable version is 64.0.0, with regular releases following semantic versioning. Key differentiators: actively maintained by Sindre Sorhus, includes many rules not found in other plugins (e.g., `better-regex`, `prefer-spread`, `no-array-for-each`), ships TypeScript types, and supports ESM-only with ESLint flat config (>=9.20.0). Requires Node ^20.10.0 or >=21.0.0 and ESLint >=9.38.0.

Common errors

error Error: Failed to load plugin 'unicorn' declared in 'plugins': Cannot find module 'eslint-plugin-unicorn' ↓

cause Plugin not installed or not in node_modules

fix

npm install --save-dev eslint-plugin-unicorn

error Error: ConfigError: Config (unnamed): Key "rules": The key 'unicorn/better-regex' is not defined in the plugin unicorn. ↓

cause Plugin not registered in plugins key

fix

Add plugins: { unicorn: eslintPluginUnicorn } to flat config

error Error: Process environment variable 'NODE_OPTIONS': --require is not supported by Node.js ↓

cause CommonJS require() used for plugin

fix

Use ESM import; set type: module in package.json

error Error: Failed to load config 'plugin:unicorn/recommended' to extend from. ↓

cause Flat config does not support extends; use configs.recommended

fix

Use eslintPluginUnicorn.configs.recommended in flat config array

Warnings

breaking ESLint flat config required >=9.20.0; legacy .eslintrc format not supported ↓

fix Migrate to eslint.config.js flat config

breaking Node.js 20.10 or higher required ↓

fix Update Node.js to ^20.10.0 or >=21.0.0

breaking Rename rules breaking change: no-array-push-push renamed to prefer-single-call, no-length-as-slice-end renamed to no-unnecessary-slice-end ↓

fix Update rule names in config

breaking ESM-only; CommonJS require() not supported ↓

fix Use import statements; set type: module in package.json

deprecated Deprecated rules (e.g., no-process-exit, no-hex-escape) removed in recent versions ↓

fix Replace with current rule alternatives or remove from config

gotcha Requires globals.builtin for languageOptions to avoid false positives ↓

fix Install globals package and include globals.builtin in config

Install

npm install eslint-plugin-unicorn

yarn add eslint-plugin-unicorn

pnpm add eslint-plugin-unicorn

Imports

default

wrong

const eslintPluginUnicorn = require('eslint-plugin-unicorn')

correct

import eslintPluginUnicorn from 'eslint-plugin-unicorn'

ESM-only; default export is the plugin object

rules

wrong

const { rules } = require('eslint-plugin-unicorn')

correct

import { rules } from 'eslint-plugin-unicorn'

CommonJS not supported; use named import in ESM

configs
```
import { configs } from 'eslint-plugin-unicorn'
```
Named export for preset configs like `configs.recommended`

Quickstart

Minimum configuration to enable eslint-plugin-unicorn in flat config with recommended languageOptions and some example rules.

// eslint.config.js
import eslintPluginUnicorn from 'eslint-plugin-unicorn';
import globals from 'globals';

export default [
  {
    languageOptions: {
      globals: globals.builtin,
    },
    plugins: {
      unicorn: eslintPluginUnicorn,
    },
    rules: {
      'unicorn/better-regex': 'error',
      'unicorn/prefer-spread': 'error',
      'unicorn/no-array-for-each': 'error',
    },
  },
];