FileValidationTestSubscriber.php

<?php

declare (strict_types=1);
namespace Drupal\file_validator_test\EventSubscriber;

use Drupal\file\Validation\FileValidationEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Provides a validation listener for file validation tests.
 */
class FileValidationTestSubscriber implements EventSubscriberInterface {
    
    /**
     * Handles the file validation event.
     *
     * @param \Drupal\file\Validation\FileValidationEvent $event
     *   The event.
     */
    public function onFileValidation(FileValidationEvent $event) : void {
        _file_test_log_call('validate', [
            $event->file
                ->id(),
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() : array {
        return [
            FileValidationEvent::class => 'onFileValidation',
        ];
    }

}