Ensure notes insertion order same as draft note

Notes should be in the same order as user comment order.

ee/app/models/draft_note.rb

@@ -2,6 +2,7 @@
 class DraftNote < ActiveRecord::Base
   include DiffPositionableNote
   include Gitlab::Utils::StrongMemoize
+  include Sortable
 
   PUBLISH_ATTRS = %i(noteable_id noteable_type type note).freeze
   DIFF_ATTRS = %i(position original_position change_position).freeze

ee/app/services/draft_notes/base_service.rb

@@ -11,7 +11,7 @@ module DraftNotes
     private
 
     def draft_notes
-      @draft_notes ||= merge_request.draft_notes.authored_by(current_user)
+      @draft_notes ||= merge_request.draft_notes.order_id_asc.authored_by(current_user)
     end
 
     def project

ee/changelogs/unreleased/9137-notes-order.yml

+---
+title: Ensure comments from merge request review is displayed in the same order as user commenting order
+merge_request: 9684
+author:
+type: fixed

ee/spec/services/draft_notes/publish_service_spec.rb

@@ -32,7 +32,8 @@ describe DraftNotes::PublishService do
 
   context 'multiple draft notes' do
     before do
-      create_list(:draft_note, 2, merge_request: merge_request, author: user)
+      create(:draft_note, merge_request: merge_request, author: user, note: 'first note')
+      create(:draft_note, merge_request: merge_request, author: user, note: 'second note')
     end
 
     context 'when review fails to create' do
@@ -63,6 +64,10 @@ describe DraftNotes::PublishService do
     it 'publishes all draft notes for a user in a merge request' do
       expect { publish }.to change { DraftNote.count }.by(-2).and change { Note.count }.by(2).and change { Review.count }.by(1)
       expect(DraftNote.count).to eq(0)
+
+      notes = merge_request.notes.order(id: :asc)
+      expect(notes.first.note).to eq('first note')
+      expect(notes.last.note).to eq('second note')
     end
 
     it 'sends batch notification' do