public function testListFilter()
{
$app = $this->makeApp();
$app['resources']->setPath('files', PHPUNIT_ROOT . '/resources/stack');
$app->initialize();
$users = $this->getMock('Bolt\\Users', array('getCurrentUser', 'saveUser'), array($app));
$app['users'] = $users;
$stack = new Stack($app);
$stack->add('files/testing.md');
$stack->add('files/testing.txt');
$stack->add('files/test.jpg');
$stack->add('files/test2.jpg');
$items = $stack->listItems(100, 'image');
$this->assertEquals(2, count($items));
$items = $stack->listItems(100, 'document');
$this->assertEquals(2, count($items));
}