Unit testing validator constraints with symfony2.3

Check the type of your element: in the validator class you use the comparator between two DateTime object but in the test you pass a string to the validator.

This is my test class:

namespace Acme\DemoBundle\Tests\Form;use Acme\DemoBundle\Validator\Constraints\Age18;use Acme\DemoBundle\Validator\Constraints\Age18Validator;class Age18ValidatorTest extends \PHPUnit_Framework_TestCase{    private $constraint;    private $context;    public function setUp()    {        $this->constraint = new Age18();        $this->context = $this->getMockBuilder('Symfony\Component\Validator\ExecutionContext')->disableOriginalConstructor()->getMock();    }    public function testValidate()    {        /*ConstraintValidator*/        $validator = new Age18Validator();        $validator->initialize( $this->context);        $this->context->expects($this->once())            ->method('addViolation')            ->with($this->constraint->message,array());        $validator->validate(\Datetime::createFromFormat("d/m/Y","10/10/2000"), $this->constraint);    }    public function tearDown()    {        $this->constraint = null;    }}

Hope this help