fix(isEmail): email starting with double quotes (#2437)

fixes #2432

src/lib/isEmail.js

@@ -109,11 +109,11 @@ export default function isEmail(str, options) {
 
   if (options.domain_specific_validation && (lower_domain === 'gmail.com' || lower_domain === 'googlemail.com')) {
     /*
-      Previously we removed dots for gmail addresses before validating.
-      This was removed because it allows `multiple..dots@gmail.com`
-      to be reported as valid, but it is not.
-      Gmail only normalizes single dots, removing them from here is pointless,
-      should be done in normalizeEmail
+    Previously we removed dots for gmail addresses before validating.
+    This was removed because it allows `multiple..dots@gmail.com`
+    to be reported as valid, but it is not.
+    Gmail only normalizes single dots, removing them from here is pointless,
+    should be done in normalizeEmail
     */
     user = user.toLowerCase();
 
@@ -166,7 +166,7 @@ export default function isEmail(str, options) {
     if (user.search(new RegExp(`[${options.blacklisted_chars}]+`, 'g')) !== -1) return false;
   }
 
-  if (user[0] === '"') {
+  if (user[0] === '"' && user[user.length - 1] === '"') {
     user = user.slice(1, user.length - 1);
     return options.allow_utf8_local_part ?
       quotedEmailUserUtf8.test(user) :

test/validators.test.js

@@ -71,6 +71,9 @@ describe('Validators', () => {
         'nbsp test@test.com',
         'nbsp_test@te st.com',
         'nbsp_test@test.co m',
+        '"foobar@gmail.com',
+        '"foo"bar@gmail.com',
+        'foo"bar"@gmail.com',
       ],
     });
   });