Issue #3358328 by alexpott, dww, mglaman: Improve how KernelTestBase manages...

use Drupal\Core\DrupalKernel;

use Drupal\Core\Entity\Sql\SqlEntityStorageInterface;

use Drupal\Core\Extension\ExtensionDiscovery;

use Drupal\Core\KeyValueStore\KeyValueMemoryFactory;

use Drupal\Core\Language\Language;

use Drupal\Core\Site\Settings;

use Drupal\Core\Test\TestDatabase;

   *

   * @var \Drupal\Core\KeyValueStore\KeyValueMemoryFactory

   */

  protected $keyValue;

  protected KeyValueMemoryFactory $keyValue;

  /**

   * The app root.

      ->register('lock', 'Drupal\Core\Lock\NullLockBackend');

    $container

      ->register('cache_factory', 'Drupal\Core\Cache\MemoryBackendFactory');

    $container

      ->register('keyvalue.memory', 'Drupal\Core\KeyValueStore\KeyValueMemoryFactory');

    $container

      ->setAlias('keyvalue', 'keyvalue.memory');

    // Must persist container rebuilds, or all data would vanish otherwise.

    if ($this->keyValue !== NULL) {

      $container->set('keyvalue.memory', $this->keyValue);

    }

    else {

      $this->keyValue = $container->get('keyvalue.memory');

    // Use memory for key value storages to avoid database queries. Store the

    // key value factory on the test object so that key value storages persist

    // container rebuilds, otherwise all state data would vanish.

    if (!isset($this->keyValue)) {

      $this->keyValue = new KeyValueMemoryFactory();

    }

    $container->set('keyvalue', $this->keyValue);

    // Set the default language on the minimal container.

    $container->setParameter('language.default_values', Language::$defaultValues);