Normalize equivalent domain names

Author: horgh

CHANGELOG.md

@@ -5,6 +5,8 @@ CHANGELOG
 ------------------
 
 * Added `PxpFinancial` and `Trustpay` to the `Processor` enum.
+* Equivalent domain names are now normalized when `hashAddress` is used.
+  For example, `googlemail.com` will become `gmail.com`.
 
 6.0.0 (2023-12-05)
 ------------------

src/request/email.spec.ts

@@ -1,4 +1,5 @@
 import { ArgumentError } from '../errors';
+import crypto from 'crypto';
 import Email from './email';
 
 describe('Email()', () => {
@@ -66,6 +67,10 @@ describe('Email()', () => {
     expect(email.domain).toBe('bar.com');
   });
 
+  const md5 = (s: string): string => {
+    return crypto.createHash('md5').update(s).digest('hex');
+  };
+
   const normalizeTests = [
     {
       email: '[email protected]',
@@ -143,6 +148,11 @@ describe('Email()', () => {
     // 'test' is rejected as invalid.
     // 'test@' is rejected as invalid.
     // 'test@.' is rejected as invalid.
+    {
+      email: '[email protected]',
+      md5: md5('[email protected]'),
+      domain: 'googlemail.com',
+    },
   ];
 
   test.each(normalizeTests)('%p', (arg) => {

src/request/email.ts

@@ -45,6 +45,17 @@ export default class Email implements EmailProps {
     'putlook.com': 'outlook.com',
   };
 
+  private static readonly equivalentDomains: { [key: string]: string } = {
+    'googlemail.com': 'gmail.com',
+    'pm.me': 'protonmail.com',
+    'proton.me': 'protonmail.com',
+    'yandex.by': 'yandex.ru',
+    'yandex.com': 'yandex.ru',
+    'yandex.kz': 'yandex.ru',
+    'yandex.ua': 'yandex.ru',
+    'ya.ru': 'yandex.ru',
+  };
+
   public constructor(email: EmailProps) {
     if (email.address != null && !isEmail(email.address)) {
       throw new ArgumentError('`email.address` is an invalid email address');
@@ -107,6 +118,10 @@ export default class Email implements EmailProps {
       domain = Email.typoDomains[domain];
     }
 
+    if (Object.prototype.hasOwnProperty.call(Email.equivalentDomains, domain)) {
+      domain = Email.equivalentDomains[domain];
+    }
+
     return domain;
   }
 }