Rewrite content_editor_spec to run with ff on and off

app/assets/javascripts/pages/shared/wikis/components/wiki_form.vue

@@ -442,6 +442,8 @@ export default {
         >
           <gl-button
             data-testid="toggle-editing-mode-button"
+            data-qa-selector="editing_mode_button"
+            :data-qa-mode="toggleEditingModeButtonText"
             variant="link"
             @click="toggleEditingMode"
             >{{ toggleEditingModeButtonText }}</gl-button

qa/qa/page/component/wiki_page_form.rb

@@ -15,6 +15,7 @@ module QA
             element :wiki_message_textbox
             element :wiki_submit_button
             element :try_new_editor_container
+            element :editing_mode_button
           end
 
           base.view 'app/assets/javascripts/pages/shared/wikis/components/delete_wiki_modal.vue' do
@@ -36,6 +37,10 @@ module QA
 
         def click_submit
           click_element(:wiki_submit_button)
+
+          wait_until(reload: false) do
+            has_no_element?(:wiki_title_textbox)
+          end
         end
 
         def delete_page
@@ -43,11 +48,19 @@ module QA
           Page::Modal::DeleteWiki.perform(&:confirm_deletion)
         end
 
-        def use_new_editor
-          within_element(:try_new_editor_container) do
-            click_button('Use the new editor')
+        def use_new_editor(toggle)
+          # Update once the feature is released, see https://gitlab.com/gitlab-org/gitlab/-/issues/345398
+          if toggle
+            click_element(:editing_mode_button, mode: 'Edit rich text')
+          else
+            within_element(:try_new_editor_container) do
+              click_button('Use the new editor')
+            end
+          end
+
+          wait_until(reload: false) do
+            has_element?(:content_editor_container)
           end
-          has_element?(:content_editor_container)
         end
       end
     end

qa/qa/specs/features/browser_ui/3_create/wiki/content_editor_spec.rb

 # frozen_string_literal: true
 
 module QA
-  RSpec.describe 'Create', quarantine: { issue: 'https://gitlab.com/gitlab-org/gitlab/-/issues/346149', type: :stale } do
+  RSpec.describe 'Create', :requires_admin do # remove :requires_admin once the ff is enabled by default in https://gitlab.com/gitlab-org/gitlab/-/issues/345398
     context 'Content Editor' do
       let(:initial_wiki) { Resource::Wiki::ProjectPage.fabricate_via_api! }
       let(:page_title) { 'Content Editor Page' }
       let(:heading_text) { 'My New Heading' }
       let(:image_file_name) { 'testfile.png' }
+      let!(:toggle) { Runtime::Feature.enabled?(:wiki_switch_between_content_editor_raw_markdown) }
 
       before do
         Flow::Login.sign_in
@@ -23,7 +24,7 @@ module QA
 
         Page::Project::Wiki::Edit.perform do |edit|
           edit.set_title(page_title)
-          edit.use_new_editor
+          edit.use_new_editor(toggle)
           edit.add_heading('Heading 1', heading_text)
           edit.upload_image(File.absolute_path(File.join('qa', 'fixtures', 'designs', image_file_name)))
         end