Add starred dashboards information

In order to allo users for quicker navigation to most used dashboards
we should expose information about starred dashboards in
metrics_dashboard endpoint

app/controllers/concerns/metrics_dashboard.rb

@@ -35,10 +35,10 @@ module MetricsDashboard
   private
 
   def all_dashboards
-    dashboards = dashboard_finder.find_all_paths(project_for_dashboard)
-    dashboards.map do |dashboard|
-      amend_dashboard(dashboard)
-    end
+    dashboard_finder
+      .find_all_paths(project_for_dashboard)
+      .map(&method(:amend_dashboard))
+      .sort_by { |dashboard| [dashboard[:starred] ? 0 : 1, dashboard[:display_name].downcase] }
   end
 
   def amend_dashboard(dashboard)
@@ -46,6 +46,8 @@ module MetricsDashboard
 
     dashboard[:can_edit] = project_dashboard ? can_edit?(dashboard) : false
     dashboard[:project_blob_path] = project_dashboard ? dashboard_project_blob_path(dashboard) : nil
+    dashboard[:starred] = starred_dashboards.include?(dashboard[:path])
+    dashboard[:user_starred_path] = nil # placeholder attribute until API endpoint will be merged https://gitlab.com/gitlab-org/gitlab/-/merge_requests/31316
 
     dashboard
   end
@@ -73,6 +75,20 @@ module MetricsDashboard
     ::Gitlab::Metrics::Dashboard::Finder
   end
 
+  def starred_dashboards
+    @starred_dashboards ||= begin
+      if project_for_dashboard.present?
+        ::Metrics::UsersStarredDashboardsFinder
+          .new(user: current_user, project: project_for_dashboard)
+          .execute
+          .map(&:dashboard_path)
+          .to_set
+      else
+        Set.new
+      end
+    end
+  end
+
   # Project is not defined for group and admin level clusters.
   def project_for_dashboard
     defined?(project) ? project : nil

changelogs/unreleased/mwam-214582-add-starred-dashboard-to-metrics-dashboard-endpoint.yml

+---
+title: Display metrics dashboards starred by user at the top of dashboard select field.
+merge_request: 31059
+author:
+type: added

spec/controllers/concerns/metrics_dashboard_spec.rb

@@ -114,6 +114,35 @@ describe MetricsDashboard do
               end
             end
           end
+
+          context 'starred dashboards' do
+            let_it_be(:dashboard_yml) { fixture_file('lib/gitlab/metrics/dashboard/sample_dashboard.yml') }
+            let_it_be(:dashboards) do
+              {
+                '.gitlab/dashboards/test.yml' => dashboard_yml,
+                '.gitlab/dashboards/anomaly.yml' => dashboard_yml,
+                '.gitlab/dashboards/errors.yml' => dashboard_yml
+              }
+            end
+            let_it_be(:project) { create(:project, :custom_repo, files: dashboards) }
+
+            before do
+              create(:metrics_users_starred_dashboard, user: user, project: project, dashboard_path: '.gitlab/dashboards/errors.yml')
+              create(:metrics_users_starred_dashboard, user: user, project: project, dashboard_path: '.gitlab/dashboards/test.yml')
+            end
+
+            it 'adds starred dashboard information and sorts the list' do
+              all_dashboards = json_response['all_dashboards'].map { |dashboard| dashboard.slice('display_name', 'starred', 'user_starred_path') }
+              expected_response = [
+                { "display_name" => "errors.yml", "starred" => true, 'user_starred_path' => nil },
+                { "display_name" => "test.yml", "starred" => true, 'user_starred_path' => nil },
+                { "display_name" => "anomaly.yml", "starred" => false, 'user_starred_path' => nil },
+                { "display_name" => "Default", "starred" => false, 'user_starred_path' => nil }
+              ]
+
+              expect(all_dashboards).to eql expected_response
+            end
+          end
         end
       end
     end