diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupDetailsForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupDetailsForm.php
index d8f5925..667f1d8 100644
--- a/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupDetailsForm.php
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupDetailsForm.php
@@ -34,6 +34,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     $form['meta'] = array(
       '#type' => 'details',
       '#title' => 'Group element',
+      '#description' => 'Details test for default description position.',
       '#open' => TRUE,
       '#group' => 'details',
     );
@@ -41,6 +42,53 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#type' => 'textfield',
       '#title' => 'Nest in details element',
     );
+    $form['details_before'] = [
+      '#type' => 'details',
+      '#title' => 'Details test for description before element',
+      '#description' => 'Details test for description before element.',
+      '#description_display' => 'before',
+    ];
+    $form['meta_before'] =[
+      '#type' => 'container',
+      '#title' => 'Group element',
+      '#group' => 'details_before',
+    ];
+    $form['meta_before']['element'] = [
+      '#type' => 'textfield',
+      '#title' => 'Nest in container element',
+    ];
+
+    $form['details_after'] = [
+      '#type' => 'details',
+      '#title' => 'Details test for description after element',
+      '#description' => 'Details test for description after element.',
+      '#description_display' => 'after',
+    ];
+    $form['meta_after'] = [
+      '#type' => 'container',
+      '#title' => 'Group element',
+      '#group' => 'details_after',
+    ];
+    $form['meta_after']['element'] = [
+      '#type' => 'textfield',
+      '#title' => 'Nest in container element',
+    ];
+
+    $form['details_invisible'] = [
+      '#type' => 'details',
+      '#title' => 'Details test for visually-hidden description',
+      '#description' => 'Details test for visually-hidden description.',
+      '#description_display' => 'invisible',
+    ];
+    $form['meta_invisible'] = [
+      '#type' => 'container',
+      '#title' => 'Group element',
+      '#group' => 'details_invisible',
+    ];
+    $form['meta_invisible']['element'] = [
+      '#type' => 'textfield',
+      '#title' => 'Nest in container element',
+    ];
     return $form;
   }