eslint-plugin-single-export

An ESLint plugin that enforces a single export per file, promoting better module organization and clarity.

Installation

pnpm add -D eslint-plugin-single-export

Usage

ESLint 9 Flat Config (eslint.config.js)

import singleExport from 'eslint-plugin-single-export'

export default [
  {
    plugins: {
      'single-export': singleExport
    },
    rules: {
      'single-export/single-export': 'error'
    }
  }
]

Recommended Config

import singleExport from 'eslint-plugin-single-export'

export default [
  singleExport.configs.recommended
]

Rule: single-export

This rule enforces that each file should have exactly one export statement.

✅ Valid

// Single default export
export default function myFunction() {}

// Single named export
export const myConstant = 42

// Single export from another module
export { something } from './other-module'

// Single re-export all
export * from './other-module'

// CommonJS single export
module.exports = myFunction

❌ Invalid

// Multiple exports
export const a = 1
export const b = 2

// Mixed default and named exports
export default function myFunction() {}
export const myConstant = 42

// Multiple default exports
export default class A {}
export default class B {}

// Multiple CommonJS exports
module.exports = a
exports.b = 2

Why Single Exports?

• Clarity: Each file has a single, clear purpose
• Discoverability: Easier to understand what a module provides
• Refactoring: Simpler to move and reorganize code
• Tree Shaking: Better optimization in bundlers
• Testing: Easier to mock and test individual modules

Development

# Install dependencies
pnpm install

# Run tests
pnpm test

# Run tests in watch mode
pnpm test:watch

# Lint the code
pnpm lint

# Release
pnpm release

License

MIT