API Platform custom normalizer for object constructor arguments

CommentNormalizer.php

<?php

// src/Serializer/CommentNormalizer.php

namespace App\Serializer;

use App\DataProvider\CurrentUserProvider;
use App\Entity\Comment;
use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
use Symfony\Component\Serializer\Normalizer\NormalizerInterface;

final class CommentNormalizer implements NormalizerInterface, DenormalizerInterface
{
    private $normalizer;
    private $currentUserProvider;

    public function __construct(NormalizerInterface $normalizer, CurrentUserProvider $currentUserProvider)
    {
        if (!$normalizer instanceof DenormalizerInterface) {
            throw new \InvalidArgumentException('The normalizer must implement the DenormalizerInterface');
        }

        $this->normalizer = $normalizer;
        $this->currentUserProvider = $currentUserProvider;
    }

    public function supportsDenormalization($data, $type, $format = null): bool
    {
        return $type === Comment::class;
    }

    public function denormalize($data, $class, $format = null, array $context = array())
    {
        $user = $this->currentUserProvider->getCurrentUser();

        // While not technically necessary as long as the route is secured properly, this is here as a fail-safe. 
        if (!$user) {
            throw new \InvalidArgumentException('You must be logged in to comment.');
        }

        return $this->normalizer->denormalize($data, $class, $format, array_merge($context, [
            'default_constructor_arguments' => [
                $class => [
                    'user' => $user,
                ],
            ],
        ]));
    }

    public function supportsNormalization($data, $format = null): bool
    {
        return $this->normalizer->supportsNormalization($data, $format);
    }

    public function normalize($object, $format = null, array $context = array())
    {
        return $this->normalizer->normalize($object, $format, $context);
    }
}