#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
import os
import os.path
 
class RemovalService(object):
    """A service for removing objects from the filesystem."""
 
    def rm(filename):
        if os.path.isfile(filename):
            os.remove(filename)

#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
from mymodule import RemovalService
import mock
import unittestclass 
 
RemovalServiceTestCase(unittest.TestCase):
 
    @mock.patch('mymodule.os.path')
    @mock.patch('mymodule.os')
    def test_rm(self, mock_os, mock_path):
        # instantiate our service
        reference = RemovalService()        
        # set up the mock
        mock_path.isfile.return_value = False
 
        reference.rm("any path")        
        # test that the remove call was NOT called.
        self.assertFalse(mock_os.remove.called, "Failed to not remove the file if not present.")        
        # make the file 'exist'
        mock_path.isfile.return_value = True
 
        reference.rm("any path")
 
        mock_os.remove.assert_called_with("any path")