Merge branch 'sh-project-feature-nplus-one' into 'master'

Remove N+1 SQL query loading project feature in dashboard

Closes #66482

See merge request gitlab-org/gitlab-ce!32169

app/controllers/dashboard/projects_controller.rb

@@ -70,6 +70,7 @@ class Dashboard::ProjectsController < Dashboard::ApplicationController
                 .new(params: finder_params, current_user: current_user)
                 .execute
                 .includes(:route, :creator, :group, namespace: [:route, :owner])
+                .preload(:project_feature)
                 .page(finder_params[:page])
 
     prepare_projects_for_rendering(projects)

changelogs/unreleased/sh-project-feature-nplus-one.yml

+---
+title: Remove N+1 SQL query loading project feature in dashboard
+merge_request: 32169
+author:
+type: performance

spec/features/dashboard/projects_spec.rb

@@ -220,4 +220,26 @@ describe 'Dashboard Projects' do
       expect(find('input#merge_request_target_branch', visible: false).value).to eq 'master'
     end
   end
+
+  it 'avoids an N+1 query in dashboard index' do
+    create(:ci_pipeline, :with_job, status: :success, project: project, ref: project.default_branch, sha: project.commit.sha)
+    visit dashboard_projects_path
+
+    control_count = ActiveRecord::QueryRecorder.new { visit dashboard_projects_path }.count
+
+    new_project = create(:project, :repository, name: 'new project')
+    create(:ci_pipeline, :with_job, status: :success, project: new_project, ref: new_project.commit.sha)
+    new_project.add_developer(user)
+
+    ActiveRecord::QueryRecorder.new { visit dashboard_projects_path }.count
+
+    # There are three known N+1 queries:
+    # 1. Project#open_issues_count
+    # 2. Project#open_merge_requests_count
+    # 3. Project#forks_count
+    #
+    # In addition, ProjectsHelper#load_pipeline_status also adds an
+    # additional query.
+    expect { visit dashboard_projects_path }.not_to exceed_query_limit(control_count + 4)
+  end
 end