Issue #3177415 by ramil g, joelpittet, jplana, kishor_kolekar: Vertical Tabs...

Issue #3177415 by ramil g, joelpittet, jplana, kishor_kolekar: Vertical Tabs CSS classes applying to non-vertical tab detail element groups

core/tests/Drupal/KernelTests/Core/Theme/ClaroVerticalTabsTest.php

+<?php
+
+namespace Drupal\KernelTests\Core\Theme;
+
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\Core\Form\FormState;
+
+/**
+ * Confirms that Claro can render vertical tabs correctly.
+ *
+ * @group Theme
+ */
+class ClaroVerticalTabsTest extends KernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['system'];
+
+  /**
+   * Confirms that Claro can render vertical tabs correctly.
+   */
+  public function testVerticalTabs() {
+    // Enable the Claro theme.
+    \Drupal::service('theme_installer')->install(['claro']);
+    $this->config('system.theme')->set('default', 'claro')->save();
+
+    $form = [
+      '#parents' => [],
+      '#array_parents' => [],
+      '#tree' => FALSE,
+    ];
+
+    $form['vertical_tabs'] = [
+      '#type' => 'vertical_tabs',
+      '#title' => 'Vertical Tabs',
+    ];
+    $form['vertical_tabs_details'] = [
+      '#type' => 'details',
+      '#title' => 'Details',
+      '#group' => 'vertical_tabs',
+    ];
+
+    // Needs to be rendered after the vertical tabs.
+    $form['container'] = [
+      '#type' => 'container',
+      '#title' => 'Container',
+    ];
+    $form['container_details'] = [
+      '#type' => 'details',
+      '#title' => 'Details',
+      '#group' => 'container',
+    ];
+
+    /** @var \Drupal\Core\Form\FormBuilderInterface $form_builder */
+    $form_builder = $this->container->get('form_builder');
+    $form_state = new FormState();
+    $form_builder->doBuildForm('form', $form, $form_state);
+    $this->render($form);
+
+    // Assert that the vertical tab details has the appropriate class.
+    $this->assertCount(1, $this->cssSelect('.vertical-tabs__items details.vertical-tabs__item'));
+    // Assert that there is a details element.
+    $this->assertCount(1, $this->cssSelect('#edit-container-details'));
+    // Assert that details element doesn't have the vertical tab classes.
+    $this->assertCount(0, $this->cssSelect('#edit-container-details.vertical-tabs__item'));
+  }
+
+}

core/themes/claro/src/ClaroPreRender.php

@@ -77,7 +77,13 @@ public static function verticalTabs($element) {
       $last_group_with_child_key = NULL;
       $last_group_with_child_key_last_child_key = NULL;
 
-      foreach ($group_keys as $group_key) {
+      // Only iterate through the parents instead of all the group keys.
+      foreach ($element['#parents'] as $group_key) {
+        // Check parents against groups because we are only looking for group
+        // elements.
+        if (!in_array($group_key, $group_keys)) {
+          continue;
+        }
         $children_keys = Element::children($element['group']['#groups'][$group_key], TRUE);
 
         foreach ($children_keys as $child_key) {