Testing symfony preUpdate event listener with phpspec

namespace My\ProductBundle\EventListener;

use Doctrine\ORM\Event\PreUpdateEventArgs;
use My\ProductBundle\Entity\Product;

class ProductEventListener
{
    /**
     * @param PreUpdateEventArgs $event
     */
    public function preUpdate(PreUpdateEventArgs $event)
    {
        $entity = $event->getObject();
        if ($entity instanceof Product) {
            if ($event->hasChangedField('price')) {
                if ($event->getOldValue('price') != $event->getNewValue('price')) {
                    $this->capturePriceChange($entity, $event->getNewValue('price'));
                }
            }
        }
    }

    /**
     * @param string  $newPrice
     * @param Product $product
     */
    private function capturePriceChange(Product $product, $newPrice)
    {
        // Do something with $price and $newPrice here
    }
}

namespace spec\My\ProductBundle\EventListener;

use Doctrine\ORM\Event\PreUpdateEventArgs;
use My\ProductBundle\Entity\Product;
use PhpSpec\ObjectBehavior;

class ProductEventListenerSpec extends ObjectBehavior
{
    function it_should_not_capture_price_change_in_the_case_of_no_change_on_pre_update_event(
        PreUpdateEventArgs $event,
        Product $product
    ) {
        $old = 123;
        $new = 123;
        $hasPriceChanged = false;

        $event->getObject()->shouldBeCalled()->willReturn($product);
        $event->hasChangedField("price")->shouldBeCalled()->willReturn($hasPriceChanged);
        $event->getOldValue("price")->shouldNotBeCalled()->willReturn($old);
        $event->getNewValue("price")->shouldNotBeCalled()->willReturn($new);

        // Do the same thing with $additionalData and $newPrice here as done in the listener
        // You can use shouldBeCalled() and willReturn(...) or shouldNotBeCalled()

        $this->preUpdate($event);
    }

    function it_should_capture_price_change_in_the_case_of_change_on_pre_update_event(
        PreUpdateEventArgs $event,
        Product $product
    ) {
        $old = 123;
        $new = 321;
        $hasPriceChanged = true;

        $event->getObject()->shouldBeCalled()->willReturn($product);
        $event->hasChangedField("price")->shouldBeCalled()->willReturn($hasPriceChanged);
        $event->getOldValue("price")->shouldBeCalled()->willReturn($old);
        $event->getNewValue("price")->shouldBeCalled()->willReturn($new);

        // Do the same thing with $additionalData and $newPrice here as done in the listener
        // You can use shouldBeCalled() and willReturn(...) or shouldNotBeCalled()

        $this->preUpdate($event);
    }
}