BlankConstraint example

class ContainerConstraintValidatorFactoryTest extends TestCase
{
    public function testGetInstanceCreatesValidator()
    {
        $factory = new ContainerConstraintValidatorFactory(new Container());
        $this->assertInstanceOf(DummyConstraintValidator::class, $factory->getInstance(new DummyConstraint()));
    }

    public function testGetInstanceReturnsExistingValidator()
    {
        $factory = new ContainerConstraintValidatorFactory(new Container());
        $v1 = $factory->getInstance(new BlankConstraint());
        $v2 = $factory->getInstance(new BlankConstraint());
        $this->assertSame($v1, $v2);
    }

    public function testGetInstanceReturnsService()
    {
        $validator = new DummyConstraintValidator();
        $container = new Container();
        $container->set(DummyConstraintValidator::class, $validator);

        $factory = new ContainerConstraintValidatorFactory($container);