2 files changed, 56 insertions, 1 deletions
diff --git a/spec/services/merge_requests/reload_diffs_service_spec.rb b/spec/services/merge_requests/reload_diffs_service_spec.rb
index 21f369a3818..546c9f277c5 100644
--- a/spec/services/merge_requests/reload_diffs_service_spec.rb
+++ b/spec/services/merge_requests/reload_diffs_service_spec.rb
@@ -60,6 +60,17 @@ describe MergeRequests::ReloadDiffsService, :use_clean_rails_memory_store_cachin
 
         subject.execute
       end
+
+      it 'avoids N+1 queries', :request_store do
+        current_user
+        merge_request
+
+        control_count = ActiveRecord::QueryRecorder.new do
+          subject.execute
+        end.count
+
+        expect { subject.execute }.not_to exceed_query_limit(control_count)
+      end
     end
   end
 end
diff --git a/spec/services/merge_requests/update_service_spec.rb b/spec/services/merge_requests/update_service_spec.rb
index 55dfab81c26..1b599ba11b6 100644
--- a/spec/services/merge_requests/update_service_spec.rb
+++ b/spec/services/merge_requests/update_service_spec.rb
@@ -315,7 +315,42 @@ describe MergeRequests::UpdateService, :mailer do
         end
       end
 
-      context 'when the milestone change' do
+      context 'when the milestone is removed' do
+        let!(:non_subscriber) { create(:user) }
+
+        let!(:subscriber) do
+          create(:user) do |u|
+            merge_request.toggle_subscription(u, project)
+            project.add_developer(u)
+          end
+        end
+
+        it_behaves_like 'system notes for milestones'
+
+        it 'sends notifications for subscribers of changed milestone' do
+          merge_request.milestone = create(:milestone)
+
+          merge_request.save
+
+          perform_enqueued_jobs do
+            update_merge_request(milestone_id: "")
+          end
+
+          should_email(subscriber)
+          should_not_email(non_subscriber)
+        end
+      end
+
+      context 'when the milestone is changed' do
+        let!(:non_subscriber) { create(:user) }
+
+        let!(:subscriber) do
+          create(:user) do |u|
+            merge_request.toggle_subscription(u, project)
+            project.add_developer(u)
+          end
+        end
+
         it 'marks pending todos as done' do
           update_merge_request({ milestone: create(:milestone) })
 
@@ -323,6 +358,15 @@ describe MergeRequests::UpdateService, :mailer do
         end
 
         it_behaves_like 'system notes for milestones'
+
+        it 'sends notifications for subscribers of changed milestone' do
+          perform_enqueued_jobs do
+            update_merge_request(milestone: create(:milestone))
+          end
+
+          should_email(subscriber)
+          should_not_email(non_subscriber)
+        end
       end
 
       context 'when the labels change' do