Do not serialize a deployment commit showing a job

app/serializers/build_details_entity.rb

@@ -13,7 +13,11 @@ class BuildDetailsEntity < JobEntity
   expose :deployment_status, if: -> (*) { build.starts_environment? } do
     expose :deployment_status, as: :status
-    expose :persisted_environment, as: :environment, with: EnvironmentEntity
+    expose :persisted_environment, as: :environment do |build, options|
+      options.merge(except: [{ last_deployment: [:commit] }]).yield_self do |opts|
+        EnvironmentEntity.represent(build.persisted_environment, opts)
+      end
+    end
   end
   expose :artifact, if: -> (*) { can?(current_user, :read_build, build) } do

spec/controllers/projects/jobs_controller_spec.rb

@@ -269,6 +269,8 @@ describe Projects::JobsController, :clean_gitlab_redis_shared_state do
           expect(json_response.dig('deployment_status', 'status')).to eq 'creating'
           expect(json_response.dig('deployment_status', 'environment')).not_to be_nil
           expect(json_response.dig('deployment_status', 'environment', 'last_deployment')).not_to be_nil
+          expect(json_response.dig('deployment_status', 'environment', 'last_deployment'))
+            .not_to include('commit')
         end
       end

spec/serializers/build_details_entity_spec.rb

@@ -122,5 +122,29 @@ describe BuildDetailsEntity do
       it { is_expected.to include(failure_reason: 'unmet_prerequisites') }
     end
+
+    context 'when a build has environment with latest deployment' do
+      let(:build) do
+        create(:ci_build, :running, environment: environment.name, pipeline: pipeline)
+      end
+
+      let(:environment) do
+        create(:environment, project: project, name: 'staging', state: :available)
+      end
+
+      before do
+        create(:deployment, :success, environment: environment, project: project)
+
+        allow(request).to receive(:project).and_return(project)
+      end
+
+      it 'does not serialize latest deployment commit' do
+        response = subject.with_indifferent_access
+
+        response.dig(:deployment_status, :environment, :last_deployment).tap do |deployment|
+          expect(deployment).not_to include(:commit)
+        end
+      end
+    end
   end
 end