Discriminator field filtered by exclusion strategy

[baptisteCable]

It seems impossible to combine discriminator and group exclusion strategy. For instance:

/**
 * @Serializer\Discriminator(field = "type", map = {
 *    "car": "Car",
 *    "moped": "Moped",
 * })
 **/
abstract class Vehicle
{
    /**
     * @Serializer\Type("integer")
     * @Serializer\Groups({"details"})
     */
    public $km;

    public function __construct($km)
    {
        $this->km = (integer)$km;
    }
}

class Moped extends Vehicle
{
}

class Car extends Vehicle
{
}

$context = SerializationContext::create();
$context->setGroups(array('details'));
$serializer = SerializerBuilder::create()->build();

$json = $serializer->serialize(new Car(200), 'json', $context);

The result is {"km":200} and not {"km":200, "type":"car"}

I guess the issue comes from the exclusion strategy. The discriminator field does not belong to the "details" group and is excluded.

Is there a way to force the creation of this field? Does it belong to a hidden group?

If it is not the case, I suggest adding a default group to every discriminator field (e.g. "_discriminator") to make possible to see them by adding this group in the SerializationContext.

For instance, I could obtain the expected result with the following code:

$context = SerializationContext::create();
$context->setGroups(array('details', '_discriminator'));
$serializer = SerializerBuilder::create()->build();

$json = $serializer->serialize(new Car(200), 'json', $context);

[gregory90]

Fields which don't belong to any custom groups, belongs to group named 'Default'. So you could have:

$context = SerializationContext::create();
$context->setGroups(array('details', 'Default'));
$serializer = SerializerBuilder::create()->build();

$json = $serializer->serialize(new Car(200), 'json', $context);

[baptisteCable]

Thank you :-)