Refactor count queries in Projects::EnvironmentsController

app/controllers/projects/environments_controller.rb

@@ -27,12 +27,13 @@ def index
       format.html
       format.json do
         Gitlab::PollingInterval.set_header(response, interval: 3_000)
+        environments_count_by_state = project.environments.count_by_state
         render json: {
           environments: serialize_environments(request, response, params[:nested]),
           review_app: serialize_review_app,
-          available_count: project.environments.available.count,
-          stopped_count: project.environments.stopped.count
+          available_count: environments_count_by_state[:available],
+          stopped_count: environments_count_by_state[:stopped]
         }
       end
     end

app/models/environment.rb

@@ -151,6 +151,14 @@ def stop_actions
                .preload(:user, :metadata, :deployment)
     end
+    def count_by_state
+      environments_count_by_state = group(:state).count
+
+      valid_states.each_with_object({}) do |state, count_hash|
+        count_hash[state] = environments_count_by_state[state.to_s] || 0
+      end
+    end
+
     private
     def cte_for_deployments_with_stop_action

changelogs/unreleased/sk-refactor-count-queries-in-environments-controller.yml

+---
+title: Refactor count queries to single query on Projects::EnvironmentsController
+merge_request: 30073
+author: Sashi Kumar
+type: other

spec/models/environment_spec.rb

@@ -1311,4 +1311,25 @@
       expect { environment.destroy }.to change { project.commit(deployment.ref_path) }.to(nil)
     end
   end
+
+  describe '.count_by_state' do
+    context 'when environments are not empty' do
+      let!(:environment1) { create(:environment, project: project, state: 'stopped') }
+      let!(:environment2) { create(:environment, project: project, state: 'available') }
+      let!(:environment3) { create(:environment, project: project, state: 'stopped') }
+
+      it 'returns the environments count grouped by state' do
+        expect(project.environments.count_by_state).to eq({ stopped: 2, available: 1 })
+      end
+
+      it 'returns the environments count grouped by state with zero value' do
+        environment2.update(state: 'stopped')
+        expect(project.environments.count_by_state).to eq({ stopped: 3, available: 0 })
+      end
+    end
+
+    it 'returns zero state counts when environments are empty' do
+      expect(project.environments.count_by_state).to eq({ stopped: 0, available: 0 })
+    end
+  end
 end