FooTest.php

<?php
namespace Foo;

use PHPUnit_Framework_TestCase;
use Zend\InputFilter\InputFilter;

class FooTest extends PHPUnit_Framework_TestCase
{
    public function testWtf()
    {
        $data = [
            'foo' => false
        ];

        $inputFilter = new InputFilter();
        $inputFilter->add([
            'name'       => 'foo',
            'required'   => false,
            'filters'    => [],
            'validators' => []
        ]);

        $inputFilter->setData($data);

        $this->assertTrue($inputFilter->isValid());
    }
}