Mock Objects Don't "use" their Traits

[theshadow]

namespace NeonDreams\User\Db;

class Serializer { 
    use \NeonDreams\Model\Serializer;
}

namespace NeonDreams\Model;

trait Serializable { 
    public function setSerializer($serializer) { 
        if (array_key_exists('NeonDreams\Model\Serializer', class_uses($serializer)) === false) {
            throw new \NeonDreams\Model\Serializable\InvalidSerializerException(
                'Expected object with trait NeonDreams\Model\Serializer'
            ); 
        }
        $this->serializer = $serializer;
        return $this;
    }
}

$serializer = $this->getMock('\NeonDreams\User\Db\Serializer');
$serializable = $this->getObjectForTrait('\NeonDreams\Model\Serializable');

$serializable->setSerializer($serializer);

NeonDreams\Model\Serializable\InvalidSerializerException: Expected object with trait NeonDreams\Model\Serializer

[sebastianbergmann]

You are using traits in a way that is not intended. Thanks to the Flattening Property (https://wiki.php.net/rfc/horizontalreuse#the_flattening_property) there is no notion of traits at runtime. The fact that the traits a class uses can be introspected using class_uses(), for instance, is a violation of the Flattening Property for the sake of meta programming.

Instead of checking whether or not an object was created based on a class that uses a certain trait you should check for an interface (which can be implemented using a trait).

[theshadow]

Fair enough. TY!