Add a spec for #3539

Author: mshibuya

spec/integration/fields/ck_editor_spec.rb

@@ -14,4 +14,19 @@
     expect { visit new_path(model_name: 'draft') }.not_to raise_error
     is_expected.to have_selector('#cke_draft_notes')
   end
+
+  it 'supports focusing on sub-modals', js: true do
+    RailsAdmin.config Comment do
+      edit do
+        field :content, :ck_editor
+      end
+    end
+    visit new_path(model_name: 'player')
+    find_link('Add a new Comment').trigger 'click'
+    expect(page).to have_text 'New Comment'
+    find('.cke_button__link').click
+    expect(page).to have_css '.cke_dialog_ui_input_text'
+    first(:css, '.cke_dialog_ui_input_text').click
+    expect(page).to have_css '.cke_dialog_ui_input_text:focus'
+  end
 end