Test case return 404 instead of 500 error

Changelog: added
EE: true

ee/app/controllers/projects/quality/test_cases_controller.rb

@@ -26,7 +26,7 @@ class Projects::Quality::TestCasesController < Projects::ApplicationController
                   .execute
                   .iid_in(params[:id])
                   .without_order
-                  .first
+                  .take! # rubocop: disable CodeReuse/ActiveRecord
 
     serializer = IssueSerializer.new(current_user: current_user, project: project)
 

ee/spec/controllers/projects/quality/test_cases_controller_spec.rb

@@ -108,6 +108,16 @@ RSpec.describe Projects::Quality::TestCasesController do
           expect(assigns(:test_case)).to eq(test_case)
           expect(assigns(:issuable_sidebar)).to be_present
         end
+
+        context 'when test case is not found' do
+          let(:test_case) { non_existing_record_id }
+
+          it 'returns 404' do
+            subject
+
+            expect(response).to have_gitlab_http_status(:not_found)
+          end
+        end
       end
     end
   end

ee/spec/features/projects/quality/test_case_show_spec.rb

@@ -179,4 +179,18 @@ RSpec.describe 'Test Cases', :js do
       end
     end
   end
+
+  describe 'for a nonexistent test case' do
+    let(:test_case) { non_existing_record_id }
+
+    it 'renders 404 page' do
+      requests = inspect_requests do
+        visit project_quality_test_case_path(project, test_case)
+
+        wait_for_all_requests
+      end
+
+      expect(requests.first.status_code).to eq(404)
+    end
+  end
 end