Issue #2477337 by jhedstrom, dawehner, tim.plunkett, sumitmadan: Add test to...

Issue #2477337 by jhedstrom, dawehner, tim.plunkett, sumitmadan: Add test to ensure saving a menu item with internal path instead of entity reference does not lose hierarchy

core/modules/menu_link_content/src/Tests/MenuLinkContentDeriverTest.php

@@ -46,11 +46,12 @@ public function testRediscover() {
     \Drupal::service('router.builder')->rebuild();
 
     // Set up a custom menu link pointing to a specific path.
-    MenuLinkContent::create([
+    $parent = MenuLinkContent::create([
       'title' => '<script>alert("Welcome to the discovered jungle!")</script>',
       'link' => [['uri' => 'internal:/example-path']],
       'menu_name' => 'tools',
-    ])->save();
+    ]);
+    $parent->save();
     $menu_tree = \Drupal::menuTree()->load('tools', new MenuTreeParameters());
     $this->assertEqual(1, count($menu_tree));
     /** @var \Drupal\Core\Menu\MenuLinkTreeElement $tree_element */
@@ -73,6 +74,39 @@ public function testRediscover() {
     $this->assertFalse($title instanceof TranslationWrapper);
     $this->assertIdentical('<script>alert("Welcome to the discovered jungle!")</script>', $title);
     $this->assertFalse(SafeMarkup::isSafe($title));
+
+    // Create a hierarchy.
+    \Drupal::state()->set('menu_link_content_dynamic_route.routes', [
+      'route_name_1' => new Route('/example-path'),
+      'route_name_2' => new Route('/example-path/child'),
+    ]);
+    $child = MenuLinkContent::create([
+      'title' => 'Child',
+      'link' => [['uri' => 'entity:/example-path/child']],
+      'menu_name' => 'tools',
+      'parent' => 'menu_link_content:' . $parent->uuid(),
+    ]);
+    $child->save();
+    $parent->set('link', [['uri' => 'entity:/example-path']]);
+    $parent->save();
+    $menu_tree = \Drupal::menuTree()->load('tools', new MenuTreeParameters());
+    $this->assertEqual(1, count($menu_tree));
+    /** @var \Drupal\Core\Menu\MenuLinkTreeElement $tree_element */
+    $tree_element = reset($menu_tree);
+    $this->assertTrue($tree_element->hasChildren);
+    $this->assertEqual(1, count($tree_element->subtree));
+
+    // Edit child element link to use 'internal' instead of 'entity'.
+    $child->set('link', [['uri' => 'internal:/example-path/child']]);
+    $child->save();
+    \Drupal::service('plugin.manager.menu.link')->rebuild();
+
+    $menu_tree = \Drupal::menuTree()->load('tools', new MenuTreeParameters());
+    $this->assertEqual(1, count($menu_tree));
+    /** @var \Drupal\Core\Menu\MenuLinkTreeElement $tree_element */
+    $tree_element = reset($menu_tree);
+    $this->assertTrue($tree_element->hasChildren);
+    $this->assertEqual(1, count($tree_element->subtree));
   }
 
 }