Exception normalizer : Allow to have message of exception

HttpProblemNormalizer.php

<?php

declare(strict_types=1);

namespace App\Normalizer;

use Symfony\Component\ErrorHandler\Exception\FlattenException;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Symfony\Component\Serializer\Normalizer\NormalizerAwareInterface;
use Symfony\Component\Serializer\Normalizer\NormalizerAwareTrait;
use Symfony\Component\Serializer\Normalizer\NormalizerInterface;

/**
 * Normalizer that allow to display Exception message only if Exception is an HttpExceptionInterface.
 */
final class HttpProblemNormalizer implements NormalizerInterface, NormalizerAwareInterface
{
    use NormalizerAwareTrait;

    private const ALREADY_CALLED = 'HTTP_PROBLEM_ALREADY_CALLED';

    /**
     * {@inheritdoc}
     */
    public function normalize(mixed $object, string $format = null, array $context = [])
    {
        $context[self::ALREADY_CALLED] = true;
        $data = $this->normalizer->normalize($object, $format, $context);

        // Force to use exception message in detail instead of status text
        $data['detail'] = $object->getMessage();

        return $data;
    }

    public function supportsNormalization($data, string $format = null, array $context = []): bool
    {
        // avoid recursion: only call once per object
        if (isset($context[self::ALREADY_CALLED])) {
            return false;
        }

        if (!$data instanceof FlattenException) {
            return false;
        }
        $implements = class_implements($data->getClass());

        return \array_key_exists(HttpExceptionInterface::class, $implements);
    }
}