From f866b549b500eef357bbbe9445a7b2efb4a57ec1 Mon Sep 17 00:00:00 2001
From: oleghasjanov <oleg.phenomenon@gmail.com>
Date: Mon, 10 Mar 2025 14:24:02 +0200
Subject: [PATCH] # Improve email validation regex pattern and add
 comprehensive tests This commit updates the email validation pattern in
 Truemail configuration to better handle various email format edge cases. The
 changes include: Refine email regex pattern in
 config/initializers/truemail.rb to properly validate: RFC compliant local
 parts with allowed special characters Proper domain name formatting
 Prevention of consecutive dots in both local part and domain Leading and
 trailing dots in local part Add comprehensive test cases in
 test/interactions/email_check_test.rb to verify: Valid email formats like
 standard addresses, underscore usage, and dot-atom formats Invalid email
 formats including consecutive dots, leading/trailing dots, and invalid
 characters These changes ensure our email validation is more RFC-compliant
 while still being strict enough to catch common errors. The test suite now
 explicitly validates both positive and negative test cases for email format
 validation.

---
 config/initializers/truemail.rb       |  2 +-
 test/interactions/email_check_test.rb | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/config/initializers/truemail.rb b/config/initializers/truemail.rb
index 10c7374c87..4893644e92 100644
--- a/config/initializers/truemail.rb
+++ b/config/initializers/truemail.rb
@@ -9,7 +9,7 @@
   # config.verifier_domain = 'internet.ee'
 
   # Optional parameter. You can override default regex pattern
-  config.email_pattern = /(?=\A.{6,255}\z)(\A([\p{L}0-9]+[\W\w]*)@(xn--)?((?i-mx:[\p{L}0-9]+([\-.]{1}[\p{L}0-9]+)*\.\p{L}{2,63}))\z)/
+  config.email_pattern = /\A([\p{L}0-9!#$%&'*+\/=?^_`{|}~-]+(?:\.[\p{L}0-9!#$%&'*+\/=?^_`{|}~-]+)*)@(?i:(xn--)?(?:[\p{L}0-9][\p{L}0-9-]{0,61}[\p{L}0-9]\.)+[\p{L}]{2,63}|\[[\d.a-fA-F:]+\])\z/
 
   # Optional parameter. You can override default regex pattern
   # config.smtp_error_body_pattern = /regex_pattern/
diff --git a/test/interactions/email_check_test.rb b/test/interactions/email_check_test.rb
index adecd37d48..3cf1ac0265 100644
--- a/test/interactions/email_check_test.rb
+++ b/test/interactions/email_check_test.rb
@@ -7,6 +7,33 @@ class EmailCheckTest < ActiveSupport::TestCase
     @contact = contacts(:john)
   end
 
+  def test_validates_regex_email_format
+    valid_emails = [
+      'user@domain.com',
+      'user_@domain.com',
+      'user.name@domain.com',
+      'hello.world@example.com',
+      '_user.email@domain.com',
+      '__user.email@domain.com',
+    ]
+
+    valid_emails.each_with_index do |email, index|
+      assert Actions::EmailCheck.new(email: email, validation_eventable: @contact, check_level: 'regex').call
+    end
+
+    invalid_emails = [
+      'user..name@domain.com',
+      '.user@domain.com',
+      'user.@domain.com',
+      'us"er@domain.com',
+      'user@domain..com'
+    ]
+
+    invalid_emails.each do |email|
+      refute Actions::EmailCheck.new(email: email, validation_eventable: @contact, check_level: 'regex').call
+    end
+  end
+
   def test_invalid_email_in_mx_level_with_a_and_aaaa_records
     Spy.on_instance_method(Actions::EmailCheck, :check_email).and_return(trumail_result)
     Spy.on_instance_method(Actions::AAndAaaaEmailValidation, :call).and_return([true])