PluginAlterTest.php

<?php

namespace Drupal\KernelTests\Core\Render\Element;

use Drupal\KernelTests\KernelTestBase;

/**
 * @group Render
 */
class PluginAlterTest extends KernelTestBase {
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'element_info_test',
  ];
  
  /**
   * Tests hook_element_plugin_alter().
   */
  public function testPluginAlter() {
    $info_manager = $this->container
      ->get('plugin.manager.element_info');
    $this->assertArrayHasKey('weight', $info_manager->getDefinitions());
    // @see element_info_test_element_plugin_alter()
    $this->container
      ->get('state')
      ->set('hook_element_plugin_alter:remove_weight', TRUE);
    // The definition will be cached.
    $this->assertArrayHasKey('weight', $info_manager->getDefinitions());
    // Clearing the caches removes the definition.
    $info_manager->clearCachedDefinitions();
    $this->assertArrayNotHasKey('weight', $info_manager->getDefinitions());
  }

}