Merge branch 'fix-n-plus-one-in-jira-github-api' into 'master'

Fix N+1 queries in Jira Development Panel API endpoint

See merge request gitlab-org/gitlab!18329

changelogs/unreleased/fix-n-plus-one-in-jira-github-api.yml

+---
+title: Fix N+1 queries in Jira Development Panel API endpoint
+merge_request: 18329
+author:
+type: performance

ee/lib/api/github/entities.rb

@@ -9,7 +9,9 @@ module API
       class Repository < Grape::Entity
         expose :id
         expose :owner do |project, options|
-          { login: project.root_namespace.path }
+          root_namespace = options[:root_namespace] || project.root_namespace
+
+          { login: root_namespace.path }
         end
         expose :name do |project, options|
           ::Gitlab::Jira::Dvcs.encode_project_name(project)

ee/lib/api/v3/github.rb

@@ -54,7 +54,7 @@ module API
           project = find_project!(
             ::Gitlab::Jira::Dvcs.restore_full_path(params.slice(:namespace, :project).symbolize_keys)
           )
-          not_found! unless licensed_project?(project)
+          not_found! unless licensed?(project)
           project
         end
 
@@ -62,7 +62,7 @@ module API
         def find_merge_requests
           merge_requests = authorized_merge_requests.reorder(updated_at: :desc).preload(:target_project)
           merge_requests = paginate(merge_requests)
-          merge_requests.select { |mr| licensed_project?(mr.target_project) }
+          merge_requests.select { |mr| licensed?(mr.target_project) }
         end
         # rubocop: enable CodeReuse/ActiveRecord
 
@@ -87,8 +87,8 @@ module API
         end
         # rubocop: enable CodeReuse/ActiveRecord
 
-        def licensed_project?(project)
-          project.feature_available?(JIRA_DEV_PANEL_FEATURE)
+        def licensed?(routable)
+          routable.feature_available?(JIRA_DEV_PANEL_FEATURE)
         end
       end
 
@@ -111,15 +111,16 @@ module API
 
         get ':namespace/repos' do
           namespace = Namespace.find_by_full_path(params[:namespace])
-          not_found!('Namespace') unless namespace
+          not_found!('Namespace') unless namespace && licensed?(namespace)
 
           projects = Project.public_or_visible_to_user(current_user)
                             .in_namespace(namespace.self_and_descendants)
-                            .to_a
-          projects.select! { |project| licensed_project?(project) }
-          projects = ::Kaminari.paginate_array(projects)
+                            .eager_load_namespace_and_owner
+                            .with_route
 
-          present paginate(projects), with: ::API::Github::Entities::Repository
+          present paginate(projects),
+                  with: ::API::Github::Entities::Repository,
+                  root_namespace: namespace.root_ancestor
         end
 
         get ':username' do

ee/spec/requests/api/v3/github_spec.rb

@@ -323,6 +323,38 @@ describe API::V3::Github do
       it 'returns an array of projects belonging to group with github format' do
         expect_project_under_namespace([parent_group_project, child_group_project], group.parent, user)
       end
+
+      context 'when namespace license checks are enabled' do
+        before do
+          enable_namespace_license_check!
+        end
+
+        context 'when the root group does not have the correct license' do
+          it 'returns not found' do
+            jira_get v3_api("/users/#{group.parent.path}/repos", user)
+
+            expect(response).to have_gitlab_http_status(404)
+          end
+        end
+
+        context 'when the root group has the correct license' do
+          before do
+            create(:gitlab_subscription, :gold, namespace: group.parent)
+          end
+
+          it 'avoids N+1 queries' do
+            jira_get v3_api("/users/#{group.parent.path}/repos", user)
+
+            control = ActiveRecord::QueryRecorder.new { jira_get v3_api("/users/#{group.parent.path}/repos", user) }
+
+            new_group = create(:group, parent: group.parent)
+            create(:project, :repository, group: new_group, creator: user)
+
+            expect { jira_get v3_api("/users/#{group.parent.path}/repos", user) }.not_to exceed_query_limit(control)
+            expect(response).to have_gitlab_http_status(200)
+          end
+        end
+      end
     end
 
     context 'user namespace' do