fix: Handle emoji and special characters in mention notifications (#11857)

Fixes notification display issues when user or team names contain emojis
and special characters. Previously, mention notifications would show
URL-encoded characters instead of properly formatted names with emojis.

  **Before:**
Notification: "John Doe: Hey @%F0%9F%91%8D%20customer%20support please
check this"

  **After:**
  Notification: "John Doe: Hey @👍 customer support please check this"

app/helpers/message_format_helper.rb

@@ -1,9 +1,13 @@
 module MessageFormatHelper
-  include RegexHelper
-
   def transform_user_mention_content(message_content)
     # attachment message without content, message_content is nil
-    message_content.presence ? message_content.gsub(MENTION_REGEX, '\1') : ''
+    return '' unless message_content.presence
+
+    # Use CommonMarker to convert markdown to plain text for notifications
+    # This handles all markdown formatting (links, bold, italic, etc.) not just mentions
+    # Converts: [@👍 customer support](mention://team/1/%F0%9F%91%8D%20customer%20support)
+    # To: @👍 customer support
+    CommonMarker.render_doc(message_content).to_plaintext.strip
   end
 
   def render_message_content(message_content)

lib/regex_helper.rb

@@ -5,7 +5,13 @@ module RegexHelper
   # valid unicode letter, unicode number, underscore, hyphen
   # shouldn't start with a underscore or hyphen
   UNICODE_CHARACTER_NUMBER_HYPHEN_UNDERSCORE = Regexp.new('\A[\p{L}\p{N}]+[\p{L}\p{N}_-]+\Z')
-  MENTION_REGEX = Regexp.new('\[(@[\w_. ]+)\]\(mention://(?:user|team)/\d+/(.*?)+\)')
+  # Regex to match mention markdown links and extract display names
+  # Matches: [@display name](mention://user|team/id/url_encoded_name)
+  # Captures: 1) @display name (including emojis), 2) url_encoded_name
+  # Uses [^]]+ to match any characters except ] in display name to support emojis
+  # NOTE: Still used by Slack integration (lib/integrations/slack/send_on_slack_service.rb)
+  # while notifications use CommonMarker for better markdown processing
+  MENTION_REGEX = Regexp.new('\[(@[^]]+)\]\(mention://(?:user|team)/\d+/([^)]+)\)')
 
   TWILIO_CHANNEL_SMS_REGEX = Regexp.new('^\+\d{1,15}\z')
   TWILIO_CHANNEL_WHATSAPP_REGEX = Regexp.new('^whatsapp:\+\d{1,15}\z')

spec/helpers/message_format_helper_spec.rb

@@ -3,9 +3,37 @@ require 'rails_helper'
 describe MessageFormatHelper do
   describe '#transform_user_mention_content' do
     context 'when transform_user_mention_content called' do
-      it 'return transormed text correctly' do
+      it 'return transformed text correctly' do
         expect(helper.transform_user_mention_content('[@john](mention://user/1/John%20K), check this ticket')).to eq '@john, check this ticket'
       end
+
+      it 'handles emoji in display names correctly' do
+        content = '[@👍 customer support](mention://team/1/%F0%9F%91%8D%20customer%20support), please help'
+        expected = '@👍 customer support, please help'
+        expect(helper.transform_user_mention_content(content)).to eq expected
+      end
+
+      it 'handles multiple mentions with emojis and spaces' do
+        content = 'Hey [@John Doe](mention://user/1/John%20Doe) and [@🚀 Dev Team](mention://team/2/%F0%9F%9A%80%20Dev%20Team)'
+        expected = 'Hey @John Doe and @🚀 Dev Team'
+        expect(helper.transform_user_mention_content(content)).to eq expected
+      end
+
+      it 'handles emoji-only team names' do
+        expect(helper.transform_user_mention_content('[@🔥](mention://team/3/%F0%9F%94%A5) urgent')).to eq '@🔥 urgent'
+      end
+
+      it 'handles special characters in names' do
+        expect(helper.transform_user_mention_content('[@user@domain.com](mention://user/4/user%40domain.com) check')).to eq '@user@domain.com check'
+      end
+
+      it 'returns empty string for nil content' do
+        expect(helper.transform_user_mention_content(nil)).to eq ''
+      end
+
+      it 'returns empty string for empty content' do
+        expect(helper.transform_user_mention_content('')).to eq ''
+      end
     end
   end
 

spec/models/notification_spec.rb

@@ -128,6 +128,39 @@ has been assigned to you"
       expect(notification.push_message_body).to eq "#{message.sender.name}: Hey @John Peter please check this?"
     end
 
+    it 'returns appropriate body suited for the notification type conversation_mention if username contains emoji' do
+      conversation = create(:conversation)
+      content = 'Hey [@👍 customer support](mention://team/1/%F0%9F%91%8D%20customer%20support) please check this?'
+      message = create(:message, sender: create(:user), content: content, conversation: conversation)
+      notification = create(:notification, notification_type: 'conversation_mention', primary_actor: conversation, secondary_actor: message)
+      expect(notification.push_message_body).to eq "#{message.sender.name}: Hey @👍 customer support please check this?"
+    end
+
+    it 'returns appropriate body suited for the notification type conversation_mention if team name contains emoji and spaces' do
+      conversation = create(:conversation)
+      content = 'Please check [@🚀 Development Team](mention://team/2/%F0%9F%9A%80%20Development%20Team)'
+      message = create(:message, sender: create(:user), content: content, conversation: conversation)
+      notification = create(:notification, notification_type: 'conversation_mention', primary_actor: conversation, secondary_actor: message)
+      expect(notification.push_message_body).to eq "#{message.sender.name}: Please check @🚀 Development Team"
+    end
+
+    it 'returns appropriate body suited for the notification type conversation_mention with mixed emoji and regular mentions' do
+      conversation = create(:conversation)
+      content = 'Hey [@John Doe](mention://user/1/John%20Doe) and ' \
+                '[@👍 customer support](mention://team/1/%F0%9F%91%8D%20customer%20support) please review'
+      message = create(:message, sender: create(:user), content: content, conversation: conversation)
+      notification = create(:notification, notification_type: 'conversation_mention', primary_actor: conversation, secondary_actor: message)
+      expect(notification.push_message_body).to eq "#{message.sender.name}: Hey @John Doe and @👍 customer support please review"
+    end
+
+    it 'returns appropriate body suited for the notification type conversation_mention with special characters in names' do
+      conversation = create(:conversation)
+      content = 'Please review [@user@domain.com](mention://user/4/user%40domain.com)'
+      message = create(:message, sender: create(:user), content: content, conversation: conversation)
+      notification = create(:notification, notification_type: 'conversation_mention', primary_actor: conversation, secondary_actor: message)
+      expect(notification.push_message_body).to eq "#{message.sender.name}: Please review @user@domain.com"
+    end
+
     it 'calls remove duplicate notification job' do
       allow(Notification::RemoveDuplicateNotificationJob).to receive(:perform_later)
       notification = create(:notification, notification_type: 'conversation_mention')