eslint-plugin-check-file

3.3.1 verified Sat Apr 25 auth: no javascript

ESLint plugin for enforcing consistent naming conventions for files and folders. Current stable version is 3.3.1, requiring Node >=18 and ESLint >=9 with flat config. Provides five rules: no-index, filename-blocklist, folder-match-with-fex, filename-naming-convention (supports built-in cases like PASCAL_CASE, CAMEL_CASE, NEXT_JS_PAGE_ROUTER_FILENAME_CASE), and folder-naming-convention. Unlike generic naming tools, it uses glob patterns to target specific file paths and supports linting non-JS/TS files via a dedicated processor. Ships TypeScript definitions.

Common errors

error Error: Cannot find module 'eslint-plugin-check-file' ↓

cause Missing dependency or wrong import path when using ESM in non-module context.

fix

Run 'npm install eslint-plugin-check-file --save-dev' and ensure the import uses ESM syntax or a bundler.

error TypeError: eslint.PLUGIN_VERSION is not a function ↓

cause Using v3 with ESLint <9 or legacy .eslintrc config.

fix

Upgrade ESLint to >=9 and switch to flat config (eslint.config.js).

error Parsing error: The keyword 'import' is reserved ↓

cause Attempting to use ESM import in a CommonJS file without .mjs extension or type:'module' in package.json.

fix

Rename eslint.config.js to eslint.config.mjs or add 'type': 'module' to package.json.

error Error: No configuration found for file '...' ↓

cause File does not match any 'files' pattern in eslint config.

fix

Add a 'files' pattern that includes the file's path (e.g., ['**/*.js']).

Warnings

breaking v3 migrated to ESM-only and flat config; Node <18 and ESLint <9 not supported. ↓

fix Upgrade Node to >=18, ESLint to >=9, and use flat config syntax (eslint.config.js).

breaking v3 requires ESLint flat config; legacy .eslintrc.* files are ignored. ↓

fix Convert .eslintrc.* to eslint.config.js using plugins array with object syntax.

deprecated v3 removes support for CommonJS; require() will throw. ↓

fix Use ESM imports (import) or dynamic import() in CJS contexts.

gotcha The 'processor' field is required for non-JS/TS files like .yaml, .webp. Without it, those files are skipped. ↓

fix Add 'processor: "check-file/eslint-processor-check-file"' to the file config block.

gotcha Glob patterns in rules must match file paths relative to the project root; incorrect patterns cause rules to silently not apply. ↓

fix Test patterns using ESLint's --debug flag or run with a single file to verify matching.

Install

npm install eslint-plugin-check-file

yarn add eslint-plugin-check-file

pnpm add eslint-plugin-check-file

Imports

checkFile

wrong

const checkFile = require('eslint-plugin-check-file')

correct

import checkFile from 'eslint-plugin-check-file'

Plugin is ESM-only in v3. CommonJS require will fail.

rules

wrong

import { rules } from 'eslint-plugin-check-file'

correct

import { rules } from 'eslint-plugin-check-file'

Access rules object if needed for custom configuration.

FlatConfig

wrong

module.exports = {
  plugins: ['check-file']
}

correct

import checkFile from 'eslint-plugin-check-file';
export default [
  { plugins: { 'check-file': checkFile } }
]

v3 only supports flat config. Legacy .eslintrc style not supported.

Quickstart

Shows the minimal flat config setup with two rules to enforce PascalCase for JSX/TSX files and CamelCase for JS/TS files, plus a folder naming rule.

// eslint.config.js
import checkFile from 'eslint-plugin-check-file';

export default [
  {
    files: ['src/**/*.{js,ts,jsx,tsx}'],
    plugins: {
      'check-file': checkFile,
    },
    rules: {
      'check-file/filename-naming-convention': [
        'error',
        {
          '**/*.{jsx,tsx}': 'PASCAL_CASE',
          '**/*.{js,ts}': 'CAMEL_CASE',
        },
      ],
      'check-file/folder-naming-convention': [
        'error',
        {
          'src/components/*': 'PASCAL_CASE',
        },
      ],
      'check-file/no-index': 'error',
    },
  },
];

// Run: npx eslint src/