AddRoleUser.php

<?php

/**
 * @file
 * Contains \Drupal\user\Plugin\Action\AddRoleUser.
 */
namespace Drupal\user\Plugin\Action;

use Drupal\Core\Annotation\Action;
use Drupal\Core\Annotation\Translation;
use Drupal\user\Plugin\Action\ChangeUserRoleBase;

/**
 * Adds a role to a user.
 *
 * @Action(
 *   id = "user_add_role_action",
 *   label = @Translation("Add a role to the selected users"),
 *   type = "user"
 * )
 */
class AddRoleUser extends ChangeUserRoleBase {

  /**
   * {@inheritdoc}
   */
  public function execute($account = NULL) {
    $rid = $this->configuration['rid'];

    // Skip adding the role to the user if they already have it.
    if ($account !== FALSE && !$account
      ->hasRole($rid)) {

      // For efficiency manually save the original account before applying
      // any changes.
      $account->original = clone $account;
      $account
        ->addRole($rid);
      $account
        ->save();
    }
  }

}