Create end-to-end test for roadmap feature

qa/qa/specs/features/ee/browser_ui/2_plan/epic/roadmap_spec.rb

+# frozen_string_literal: true
+
+module QA
+  # https://gitlab.com/gitlab-org/gitlab-ee/issues/13360
+  context 'Plan', :quarantine do
+    describe 'Epics roadmap' do
+      let(:epic) do
+        EE::Resource::Epic.fabricate_via_api! do |epic|
+          current_date = DateTime.now
+          current_date_yyyy_mm_dd = current_date.strftime("%Y/%m/%d")
+          next_month_date_yyyy_mm_dd = current_date.next_month.strftime("%Y/%m/%d")
+
+          epic.title = 'Epic created via API to test roadmap'
+          epic.start_date_is_fixed = true
+          epic.start_date_fixed = current_date_yyyy_mm_dd
+          epic.due_date_is_fixed = true
+          epic.due_date_fixed = next_month_date_yyyy_mm_dd
+        end
+      end
+
+      before do
+        Runtime::Browser.visit(:gitlab, Page::Main::Login)
+        Page::Main::Login.perform(&:sign_in_using_credentials)
+      end
+
+      it 'presents epic on roadmap' do
+        page.visit("#{epic.group.web_url}/-/roadmap")
+
+        EE::Page::Group::Roadmap.perform do |roadmap|
+          expect(roadmap.epic_present?(epic)).to be_truthy
+        end
+      end
+    end
+  end
+end