eslint-plugin-folders

1.0.4 verified Sat Apr 25 auth: no javascript

An ESLint plugin that enforces consistent folder naming conventions for JavaScript/JSX files using regular expressions. Current stable version is 1.0.4. The plugin provides a single rule `match-regex` that can be configured with a regex pattern and a root directory. It only lints folders containing `.js` or `.jsx` files processed by ESLint. Alternatives like `eslint-plugin-import` or `eslint-plugin-filenames` focus on filenames, not folder names. The plugin requires ESLint >=1.0.0 as a peer dependency.

Common errors

error Error: .eslintrc: Configuration for rule "folders/match-regex" is invalid ↓

cause The rule configuration format is wrong; typically the regex is not a string.

fix

Use an array: [severity, patternString, rootPath]. E.g., [2, "^[a-z]+$", "."].

error Error: Cannot find module 'eslint-plugin-folders' ↓

cause Plugin not installed as a dev dependency.

fix

Run: npm install eslint-plugin-folders --save-dev

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

cause ESLint is not configured for ES6 syntax.

fix

Set parserOptions: { ecmaVersion: 6 } in .eslintrc or use a parser like babel-eslint.

Warnings

gotcha The plugin only lints folders of .js and .jsx files. Folders without JS/JSX files are ignored. ↓

fix Ensure each folder you want to lint contains at least one .js or .jsx file that ESLint processes.

gotcha The regex pattern is provided as a string without delimiters. E.g., '^[a-z_]+$' not '/^[a-z_]+$/'. ↓

fix Use plain regex string without surrounding slashes.

breaking ESLint >=1.0.0 required. Older versions may not load the plugin correctly. ↓

fix Upgrade ESLint to version 1.0.0 or later.

Install

npm install eslint-plugin-folders

yarn add eslint-plugin-folders

pnpm add eslint-plugin-folders

Imports

default

wrong

import folders from 'eslint-plugin-folders'

correct

module.exports = {
  plugins: ['folders'],
  rules: { 'folders/match-regex': [2, '^[a-z_]+$', '/root/'] }
};

This is an ESLint plugin, not a standalone module. It's configured via .eslintrc rather than imported in code.

match-regex
wrong
```
"folders/match-regex": [2, "/^[a-z_]+$/", "/root/"]
```
correct
```
"folders/match-regex": [2, "^[a-z_]+$", "/root/"]
```
The regex is provided as a string without slashes. The second parameter is the root path.

RULES

wrong

const { matchRegex } = require('eslint-plugin-folders');

correct

const rules = require('eslint-plugin-folders').rules; console.log(Object.keys(rules));

The plugin exposes a rules object. Individual rules are accessed via string keys like 'match-regex'.

Quickstart

Shows how to configure the match-regex rule in .eslintrc.json to enforce snake_case folder names.

// .eslintrc.json
{
  "plugins": ["folders"],
  "rules": {
    "folders/match-regex": [2, "^[a-z_]+$", "."]
  }
}

// This config enforces snake_case folder names in all folders below the root.
// To test, create a folder with a wrong name (e.g., 'MyFolder') containing a JS file.
// Run ESLint: npx eslint .
// You'll see an error like:
//   error  Folder 'MyFolder' doesn't match the pattern ^[a-z_]+$  folders/match-regex