1 files changed, 52 insertions, 0 deletions
diff --git a/spec/services/notification_recipients/build_service_spec.rb b/spec/services/notification_recipients/build_service_spec.rb
index 2e848c2f04d..e203093623d 100644
--- a/spec/services/notification_recipients/build_service_spec.rb
+++ b/spec/services/notification_recipients/build_service_spec.rb
@@ -58,4 +58,56 @@ describe NotificationRecipients::BuildService do
       end
     end
   end
+
+  describe '#build_new_review_recipients' do
+    let(:merge_request) { create(:merge_request, source_project: project, target_project: project) }
+    let(:review) { create(:review, merge_request: merge_request, project: project, author: merge_request.author) }
+    let(:notes) { create_list(:note_on_merge_request, 3, review: review, noteable: review.merge_request, project: review.project) }
+
+    shared_examples 'no N+1 queries' do
+      it 'avoids N+1 queries', :request_store do
+        create_user
+
+        service.build_new_review_recipients(review)
+
+        control_count = ActiveRecord::QueryRecorder.new do
+          service.build_new_review_recipients(review)
+        end
+
+        create_user
+
+        expect { service.build_new_review_recipients(review) }.not_to exceed_query_limit(control_count)
+      end
+    end
+
+    context 'when there are multiple watchers' do
+      def create_user
+        watcher = create(:user)
+        create(:notification_setting, source: project, user: watcher, level: :watch)
+
+        other_projects.each do |other_project|
+          create(:notification_setting, source: other_project, user: watcher, level: :watch)
+        end
+      end
+
+      include_examples 'no N+1 queries'
+    end
+
+    context 'when there are multiple subscribers' do
+      def create_user
+        subscriber = create(:user)
+        merge_request.subscriptions.create(user: subscriber, project: project, subscribed: true)
+      end
+
+      include_examples 'no N+1 queries'
+
+      context 'when the project is private' do
+        before do
+          project.update!(visibility_level: Gitlab::VisibilityLevel::PRIVATE)
+        end
+
+        include_examples 'no N+1 queries'
+      end
+    end
+  end
 end