instanceof twig test

extension.php

<?php

class LayoutExtension extends \Twig_Extension
{
    /**
     * {@inheritdoc}
     */
    public function getName()
    {
        return 'yolo';
    }

    /**
     * {@inheritdoc}
     */
    public function getTests()
    {
        return array(
            new \Twig_SimpleTest('instanceof', array($this, 'isInstanceOf'))
        );
    }

    public function isInstanceOf($object, $class)
    {
        $reflectionClass = new \ReflectionClass($class);

        return $reflectionClass->isInstance($object);
    }
}

👍 😃

Nice ! Thanks you for the ReflectionClass->isInstance() tips !
I just think you can remove getName() implementation because (from doc in \Twig_Extension) :
@deprecated since 1.26 (to be removed in 2.0), not used anymore internally