class MenuLinkReorderTest

class MenuLinkReorderTest extends BrowserTestBase {
  
  /**
   * An administrator user.
   *
   * @var \Drupal\user\UserInterface
   */
  protected $administrator;
  
  /**
   * Modules to enable.
   *
   * @var array
   */
  protected static $modules = [
    'menu_ui',
    'test_page_test',
    'node',
    'block',
  ];
  
  /**
   * {@inheritdoc}
   */
  protected $defaultTheme = 'stark';
  
  /**
   * Tests creating, editing, deleting menu links via node form widget.
   */
  public function testDefaultMenuLinkReorder() {
    // Add the main menu block.
    $this->drupalPlaceBlock('system_menu_block:main');
    // Assert that the Home link is available.
    $this->drupalGet('test-page');
    $this->assertSession()
      ->linkExists('Home');
    // The administrator user that can re-order menu links.
    $this->administrator = $this->drupalCreateUser([
      'administer site configuration',
      'access administration pages',
      'administer menu',
    ]);
    $this->drupalLogin($this->administrator);
    // Change the weight of the link to a non default value.
    $edit = [
      'links[menu_plugin_id:test_page_test.front_page][weight]' => -10,
    ];
    $this->drupalGet('admin/structure/menu/manage/main');
    $this->submitForm($edit, 'Save');
    // The link is still there.
    $this->drupalGet('test-page');
    $this->assertSession()
      ->linkExists('Home');
    // Clear all caches.
    $this->drupalGet('admin/config/development/performance');
    $this->submitForm([], 'Clear all caches');
    // Clearing all caches should not affect the state of the menu link.
    $this->drupalGet('test-page');
    $this->assertSession()
      ->linkExists('Home');
  }

}