SwitchUserController.php

<?php

namespace Drupal\devel\Controller;

use Drupal\Core\Controller\ControllerBase;
use Drupal\Core\Session\AccountProxyInterface;
use Drupal\Core\Session\SessionManagerInterface;
use Drupal\user\UserStorageInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\Session\Session;
use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;

/**
 * Controller for switch to another user account.
 */
class SwitchUserController extends ControllerBase {
  
  /**
   * The current user.
   */
  protected AccountProxyInterface $account;
  
  /**
   * The user storage.
   */
  protected UserStorageInterface $userStorage;
  
  /**
   * The session manager service.
   */
  protected SessionManagerInterface $sessionManager;
  
  /**
   * The session.
   */
  protected Session $session;
  
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) : static {
    $instance = parent::create($container);
    $instance->account = $container->get('current_user');
    $instance->userStorage = $container->get('entity_type.manager')
      ->getStorage('user');
    $instance->moduleHandler = $container->get('module_handler');
    $instance->sessionManager = $container->get('session_manager');
    $instance->session = $container->get('session');
    return $instance;
  }
  
  /**
   * Switches to a different user.
   *
   * We don't call session_save_session() because we really want to change
   * users. Usually unsafe!
   *
   * @param string|null $name
   *   The username to switch to, or NULL to log out.
   *
   * @return \Symfony\Component\HttpFoundation\RedirectResponse
   *   A redirect response object.
   *
   * @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
   */
  public function switchUser(?string $name = NULL) {
    if (empty($name) || !$account = $this->userStorage
      ->loadByProperties([
      'name' => $name,
    ])) {
      throw new AccessDeniedHttpException();
    }
    $account = reset($account);
    // Call logout hooks when switching from original user.
    $this->moduleHandler
      ->invokeAll('user_logout', [
      $this->account,
    ]);
    // Regenerate the session ID to prevent against session fixation attacks.
    $this->sessionManager
      ->regenerate();
    // Based off masquarade module as:
    // https://www.drupal.org/node/218104 doesn't stick and instead only
    // keeps context until redirect.
    $this->account
      ->setAccount($account);
    $this->session
      ->set('uid', $account->id());
    // Call all login hooks when switching to masquerading user.
    $this->moduleHandler
      ->invokeAll('user_login', [
      $account,
    ]);
    return $this->redirect('<front>');
  }

}