FileNameLengthConstraint.php

<?php

namespace Drupal\file\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Symfony\Component\Validator\Constraint as SymfonyConstraint;

/**
 * File name length constraint.
 */
class FileNameLengthConstraint extends SymfonyConstraint {
  
  /**
   * The maximum file name length.
   *
   * @var int
   */
  public int $maxLength = 240;
  
  /**
   * The message when file name is empty.
   *
   * @var string
   */
  public string $messageEmpty = "The file's name is empty. Enter a name for the file.";
  
  /**
   * The message when file name is too long.
   *
   * @var string
   */
  public string $messageTooLong = "The file's name exceeds the %maxLength characters limit. Rename the file and try again.";

}