--TEST-- MongoDB\BSON\ObjectId::jsonSerialize() return value --FILE-- <?php $oid = new MongoDB\BSON\ObjectId('5820ca4bef62d52d9924d0d8'); var_dump($oid->jsonSerialize()); ?> ===DONE=== <?php exit(0); ?> --EXPECT-- array(1) { ["$oid"]=> string(24) "5820ca4bef62d52d9924d0d8" } ===DONE===