Use notificationService for MR reassigned

app/observers/merge_request_observer.rb

@@ -6,29 +6,20 @@ class MergeRequestObserver < ActiveRecord::Observer
   end
 
   def after_close(merge_request, transition)
-    send_reassigned_email(merge_request) if merge_request.is_being_reassigned?
-
     Note.create_status_change_note(merge_request, current_user, merge_request.state)
   end
 
   def after_reopen(merge_request, transition)
-    send_reassigned_email(merge_request) if merge_request.is_being_reassigned?
-
     Note.create_status_change_note(merge_request, current_user, merge_request.state)
   end
 
   def after_update(merge_request)
-    send_reassigned_email(merge_request) if merge_request.is_being_reassigned?
+    notification.reassigned_merge_request(merge_request) if merge_request.is_being_reassigned?
   end
 
   protected
 
-  def send_reassigned_email(merge_request)
-    recipients_ids = merge_request.assignee_id_was, merge_request.assignee_id
-    recipients_ids.delete current_user.id
-
-    recipients_ids.each do |recipient_id|
-      Notify.delay.reassigned_merge_request_email(recipient_id, merge_request.id, merge_request.assignee_id_was)
-    end
+  def notification
+    NotificationService.new
   end
 end

app/services/notification_service.rb

@@ -33,8 +33,8 @@ class NotificationService
 
   # When we reassign an issue we should send next emails:
   #
-  #  * issue author if his notification level is not Disabled
-  #  * issue assignee if his notification level is not Disabled
+  #  * issue old assignee if his notification level is not Disabled
+  #  * issue new assignee if his notification level is not Disabled
   #
   def reassigned_issue(issue, current_user)
     recipient_ids = [issue.assignee_id, issue.assignee_id_was].compact.uniq
@@ -66,4 +66,18 @@ class NotificationService
       Notify.delay.new_merge_request_email(merge_request.id)
     end
   end
+
+  # When we reassign a merge_request we should send next emails:
+  #
+  #  * merge_request old assignee if his notification level is not Disabled
+  #  * merge_request assignee if his notification level is not Disabled
+  #
+  def reassigned_merge_request(merge_request, current_user)
+    recipients_ids = merge_request.assignee_id_was, merge_request.assignee_id
+    recipients_ids.delete current_user.id
+
+    recipients_ids.each do |recipient_id|
+      Notify.delay.reassigned_merge_request_email(recipient_id, merge_request.id, merge_request.assignee_id_was)
+    end
+  end
 end