def mock_file_manager(envelope_peer_spooled, mock_file_path):
file_manager = MagicMock(FileManager)
file_manager.open_file = CoroutineMock()
file_manager.open_file.return_value = envelope_peer_spooled
file_manager.save_file = CoroutineMock()
file_manager.save_file.return_value = mock_file_path
file_manager._file_path = mock_file_path
return file_manager
