@lowerdeck/normalize-email

Normalize email addresses to their canonical form. Handles Gmail dots, plus-addressing, and domain variations to prevent duplicate accounts.

Installation

npm install @lowerdeck/normalize-email
yarn add @lowerdeck/normalize-email
bun add @lowerdeck/normalize-email
pnpm add @lowerdeck/normalize-email

Usage

import { normalizeEmail } from '@lowerdeck/normalize-email';

// Remove dots in Gmail addresses
normalizeEmail('[email protected]');
// => '[email protected]'

// Remove plus-addressing
normalizeEmail('[email protected]');
// => '[email protected]'

// Handle googlemail.com -> gmail.com
normalizeEmail('[email protected]');
// => '[email protected]'

// Combine all normalization rules
normalizeEmail('[email protected]');
// => '[email protected]'

// Prevent duplicate accounts
const users = new Map();
function registerUser(email: string) {
  const normalized = normalizeEmail(email);

  if (users.has(normalized)) {
    throw new Error('Account already exists');
  }

  users.set(normalized, { email });
}

License

This project is licensed under the Apache License 2.0.