Doctrine Collections should be an array #37041
Description
Symfony version(s) affected: 4.4.9
Description
After this change #36601 empty Doctrine Collections became objects instead of empty arrays
How to reproduce
use Doctrine\Common\Collections\ArrayCollection;
use Symfony\Component\Serializer\Encoder\JsonEncoder;
use Symfony\Component\Serializer\Serializer;
$serializer = new Serializer([], [new JsonEncoder()]);
$arr = new ArrayCollection();
echo $serializer->serialize($arr, 'json');
// 4.4.8 - []
// 4.4.9 - {}