FileSanitizationEventSubscriber.php

<?php

namespace Drupal\file_validator_test\EventSubscriber;

use Drupal\Core\File\Event\FileUploadSanitizeNameEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Provides a file sanitization listener for file upload tests.
 */
class FileSanitizationEventSubscriber implements EventSubscriberInterface {
    
    /**
     * The allowed extensions.
     *
     * @var string[]
     */
    protected array $allowedExtensions = [];
    
    /**
     * Handles the file sanitization event.
     */
    public function onFileSanitization(FileUploadSanitizeNameEvent $event) {
        $this->allowedExtensions = $event->getAllowedExtensions();
    }
    
    /**
     * Gets the allowed extensions.
     *
     * @return string[]
     *   The allowed extensions.
     */
    public function getAllowedExtensions() : array {
        return $this->allowedExtensions;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() : array {
        return [
            FileUploadSanitizeNameEvent::class => 'onFileSanitization',
        ];
    }

}