Asserts that a file does not exist in the database.
function assertFileEntryNotExists($file, $message) {
entity_get_controller('file')
->resetCache();
$message = isset($message) ? $message : format_string('File %file exists in database at the correct path.', array(
'%file' => $file->uri,
));
$this
->assertFalse(file_load($file->fid), $message);
}