chore: Change the notification text for mention notification type (#2534)

spec/helpers/message_format_helper_spec.rb

@@ -0,0 +1,11 @@
+require 'rails_helper'
+
+describe MessageFormatHelper, type: :helper do
+  describe '#transform_user_mention_content' do
+    context 'when transform_user_mention_content called' do
+      it 'return transormed 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
+    end
+  end
+end