A good amount of people have expressed interest in unit testing file uploads. sfTestBrowser does not currently support this but we can use sfWebBrowser instead, as follows (uploadTest.php, to be placed in your unit tests directory):

require_once(dirname(__FILE__).'/../bootstrap/unit.php');
require_once(dirname(__FILE__).'/../../plugins/sfWebBrowserPlugin/lib/sfWebBrowser.class.php');
require_once(dirname(__FILE__).'/../../plugins/sfWebBrowserPlugin/lib/sfCurlAdapter.class.php');
require_once($sf_symfony_lib_dir.'/config/sfConfig.class.php');
require_once($sf_symfony_lib_dir.'/util/sfToolkit.class.php');
sfConfig::set('sf_data_dir', dirname(__FILE__).'/../../data');
$file = dirname(__FILE__).'/../fixtures/photos/maine01.jpg';
$invalid_file = dirname(__FILE__).'/../fixtures/photos/maine01.foo';
 
$t = new lime_test(2, new lime_output_color());
 
$b = new sfWebBrowser();
$b->post('http://mysite/upload', array(
  'file' => $file
));
$t->like($b->getResponseText(), '/has been uploaded/', 'file uploads successfully');
$b->post('/upload', array(
  'file' => $invalid_file
));
$t->like($b->getResponseText(), '/we only allow images/', 'unsupported mime types are not uploaded');
 

N.B. You must have curl installed for this to work.