eslint-plugin-case-police

2.2.1 verified Sat Apr 25 auth: no javascript

ESLint plugin that enforces correct casing of brand names, technologies, and terms (e.g., 'GitHub', 'npm', 'TypeScript') by linting against a curated dictionary. Version 2.2.1 is current; requires ESLint ^9.9.0 or ^10.0.0. Uses flat config (ESLint 9+). Maintained by Anthony Fu with regular updates to dictionary entries. Differentiates from style linting rules by focusing exclusively on known proper nouns.

Common errors

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

cause Missing or incorrect plugin import in flat config.

fix

Ensure you have installed the package and imported it correctly: import casePolice from 'eslint-plugin-case-police'

error Configuration for rule 'case-police/no-case-police' is invalid ↓

cause Using .eslintrc config instead of flat config.

fix

Switch to eslint.config.js with plugins object.

error TypeError: Cannot read properties of undefined (reading 'getFilename') ↓

cause Plugin expects ESLint 10+ compatibility fix; ensure v2.2.0+ is installed.

fix

Update to eslint-plugin-case-police@2.2.0 or later.

Warnings

breaking V2.0.0 drops support for .eslintrc config; requires flat config (ESLint 9+). ↓

fix Migrate to flat config (eslint.config.js).

breaking V0.7.0 drops support for ESLint <9. ↓

fix Upgrade ESLint to version 9 or later.

gotcha Plugin only checks tokens against known dictionary; does not enforce arbitrary capitalization. ↓

fix Extend dictionary if needed via `case-police` package or wait for upstream updates.

Install

npm install eslint-plugin-case-police

yarn add eslint-plugin-case-police

pnpm add eslint-plugin-case-police

Imports

default

wrong

const casePolice = require('eslint-plugin-case-police')

correct

import casePolice from 'eslint-plugin-case-police'

ESM-only since v2; CommonJS require works but is not recommended.

plugin

wrong

import { casePolice } from 'eslint-plugin-case-police'

correct

import casePolice from 'eslint-plugin-case-police'

Default export is the plugin object; named export does not exist.

rule in flat config

wrong

rules: { 'case-police/no-case-police': 'error' } without plugins

correct

plugins: { 'case-police': casePolice }, rules: { 'case-police/no-case-police': 'error' }

Must register plugin in flat config; ESLint 9+.

Quickstart

Configure ESLint flat config to lint for incorrect casing of brand names and terms.

// eslint.config.js
import casePolice from 'eslint-plugin-case-police';

export default [
  {
    plugins: {
      'case-police': casePolice,
    },
    rules: {
      'case-police/no-case-police': 'error',
    },
  },
];