Merge pull request #2764 from internetee/2747-multiple-underscores-in-email-addresses

# Improve email validation regex pattern and add comprehensive tests

config/initializers/truemail.rb

@@ -8,10 +8,8 @@ Truemail.configure do |config|
   # By default verifier domain based on verifier email
   # config.verifier_domain = 'internet.ee'
 
-  # Optional parameter. You can override default regex pattern
+  config.email_pattern = /\A(?=[\p{L}0-9!#$%&'*+\/=?^_{|}~-]*[\p{L}0-9])([\p{L}0-9!#$%&'*+\/=?^_{|}~-]+(?:\.[\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/
-  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)/
 
-  # Optional parameter. You can override default regex pattern
   # config.smtp_error_body_pattern = /regex_pattern/
 
   # Optional parameter. Connection timeout is equal to 2 ms by default.

test/interactions/email_check_test.rb

@@ -7,6 +7,36 @@ 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 = [
+      '@@domain.com',
+      '`@domain.com',
+      'user..name@domain.com',
+      '.user@domain.com',
+      'user.@domain.com',
+      'us"er@domain.com',
+      'user@domain..com',
+      '~@internet.ee'
+    ]
+
+    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])