EnumConstraintValidator.php

<?php

declare (strict_types=1);
namespace Drupal\Core\Validation\Plugin\Validation\Constraint;

use Drupal\Core\TypedData\Validation\TypedDataAwareValidatorTrait;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;

/**
 * Validates the Enum constraint.
 */
class EnumConstraintValidator extends ConstraintValidator {
  use TypedDataAwareValidatorTrait;
  
  /**
   * {@inheritdoc}
   */
  public function validate(mixed $value, Constraint $constraint) : void {
    if (!isset($value)) {
      return;
    }
    if (!$constraint instanceof EnumConstraint) {
      throw new UnexpectedTypeException($constraint, EnumConstraint::class);
    }
    $class = $this->getTypedData()
      ->getDataDefinition()['enum_class'] ?? '';
    if (empty($class)) {
      $this->context
        ->addViolation($constraint->missingClassMessage);
      return;
    }
    if (!$value instanceof \UnitEnum) {
      $this->context
        ->addViolation($constraint->notEnumMessage);
      return;
    }
    if (!$value instanceof $class) {
      $this->context
        ->addViolation($constraint->invalidClassMessage, [
        '%class' => $class,
      ]);
    }
  }

}