Put owner and participating people first

app/services/projects/participants_service.rb

 module Projects
   class ParticipantsService < BaseService
     def execute(note_type, note_id)
+      @target = get_target(note_type, note_id)
       participating =
         if note_type && note_id
           participants_in(note_type, note_id)
@@ -8,12 +9,11 @@ module Projects
           []
         end
       project_members = sorted(project.team.members)
-      participants = all_members + groups + project_members + participating
+      participants = target_owner + participating + all_members + groups + project_members
       participants.uniq
     end
 
-    def participants_in(type, id)
-      target = 
+    def get_target(type, id)
       case type
       when "Issue"
         project.issues.find_by_iid(id)
@@ -22,10 +22,19 @@ module Projects
       when "Commit"
         project.commit(id)
       end
+    end
 
-      return [] unless target
+    def target_owner
+      [{
+        name: @target.author.name,
+        username: @target.author.username
+      }]
+    end
+
+    def participants_in(type, id)
+      return [] unless @target
 
-      users = target.participants(current_user)
+      users = @target.participants(current_user)
       sorted(users)
     end