eslint-plugin-square

26.0.1 verified Fri May 01 auth: no javascript

Square's custom ESLint plugin that consolidates frontend linting rules and configurations including base, Ember, React, strict, and TypeScript configs. Current stable version is 26.0.1, requires Node ^18.0.0 || >=20.0.0 and ESLint >= 8.40.0. Ships TypeScript types, integrates eslint-plugin-import, eslint-plugin-unicorn, eslint-plugin-react, eslint-plugin-react-hooks, eslint-plugin-jsx-a11y, prettier, and more. Not recommended for public use outside Square. Breaking changes in v26: dropped Node v16 support; v24 added warning on unused ESLint disable directives in base config.

Common errors

error Error: ESLint couldn't find the plugin "eslint-plugin-square". ↓

cause Missing installed package or incorrect configuration.

fix

Run 'yarn add --dev eslint-plugin-square' or check node_modules.

error Oops! Something went wrong! :( ESLint: 8.x. Error: Configuration for rule "unicorn/xxx" is invalid. ↓

cause Breaking change in eslint-plugin-unicorn major version bump.

fix

Update eslint-plugin-square to v25+ or pin eslint-plugin-unicorn to compatible version.

error TypeError: Cannot destructure property 'configs' of 'require(...)' as it is undefined. ↓

cause Trying to import named exports via require() in a CJS file; plugin may be ESM-only in recent versions.

fix

Use dynamic import() or switch to ESM (eslint.config.js) with import statement.

Warnings

breaking Node v16 support dropped in v26.0.0. Must use Node ^18.0.0 || >=20.0.0. ↓

fix Upgrade Node to 18 or 20+.

breaking Unused ESLint disable directives now warn by default in base config since v24.0.0. ↓

fix Use --report-unused-disable-directives to check, or disable with 'no-unused-disable-directives': 'off'.

deprecated eslint-plugin-unicorn v46+ introduced breaking changes; base config updated in v25.0.0. ↓

fix Ensure you're using eslint-plugin-square v25+ if you depend on Unicorn rules.

gotcha The plugin is not recommended for public use outside Square; configs may change without notice. ↓

fix If using externally, pin to a specific version and expect breaking changes.

gotcha ESM projects must use .eslintrc.cjs instead of .eslintrc.js when using CommonJS config export. ↓

fix Rename to .eslintrc.cjs or use ESM config format (eslint.config.js with export default).

Install

npm install eslint-plugin-square

yarn add eslint-plugin-square

pnpm add eslint-plugin-square

Imports

plugin
wrong
```
module.exports = { plugins: ['square'] }
```
correct
```
module.exports = { extends: ['plugin:square/base'] }
```
Use the extends syntax to load a preset config; adding as a plugin alone does not activate rules.

configs

wrong

const baseConfig = require('eslint-plugin-square').base;

correct

import { configs } from 'eslint-plugin-square'; const baseConfig = configs.base;

ESM-only since v26? Check package.json exports. Named export 'configs' contains all preset configurations.

rules

wrong

const noRestrictedFilesRule = require('eslint-plugin-square').rules['no-restricted-files'];

correct

import { rules } from 'eslint-plugin-square'; const noRestrictedFilesRule = rules['no-restricted-files'];

ESM import for custom rules; use named export 'rules'. Available since v23.1.0.

FlatConfig
```
import { FlatConfig } from 'eslint-plugin-square'; export default [...FlatConfig];
```
ESM-only, available in v26+? Type exported for flat config usage. Not available in CJS.

Quickstart

Shows how to install, configure the base preset in a .eslintrc.cjs file, and set up npm-run-all scripts.

// Install:
// yarn add --dev eslint eslint-plugin-square npm-run-all

// .eslintrc.cjs (CommonJS):
module.exports = {
  extends: ['plugin:square/base'],
  env: { browser: true, node: true },
};

// package.json scripts:
{
  "scripts": {
    "lint": "npm-run-all --continue-on-error --aggregate-output --parallel lint:*",
    "lint:js": "eslint --report-unused-disable-directives --cache ."
  }
}

// Then run:
// yarn lint