'OS ListDirectory on a file will raise.'

def testListDirectoryOnFile(self):

    client_mock = action_mocks.ListDirectoryClientMock()
    pb = rdf_paths.PathSpec(path=os.path.join(self.base_path, 'test_img.dd'), pathtype=rdf_paths.PathSpec.PathType.OS)
    self.assertRaises(RuntimeError, list, flow_test_lib.TestFlowHelper(filesystem.ListDirectory.__name__, client_mock, client_id=self.client_id, pathspec=pb, token=self.token))
