Wie spottet man das Eingabeverzeichnis für meinen Komponententest?

Question

auf eine frühere Frage von mir Verwandte: How to unit test a method that calculates the size of a dir? Ich möchte diese Funktion zu Unit-Test:

def get_dir_size(dir_path): 
    """Determine the size of a dir. 

    This function also takes into account the allocated size of 
    directories (4096 bytes). 

    Note: The function may crash on symlinks with something like: 
    OSError: [Errno 40] Too many levels of symbolic links 

    :param dir_path (str): path to the directory 
    :return: size in bytes. 
    """ 
    tot_size = 0 
    for (root_path, dirnames, filenames) in os.walk(dir_path): 
     for f in filenames: 
      fpath = os.path.join(root_path, f) 
      tot_size += os.path.getsize(fpath) 
     tot_size += os.path.getsize(root_path) 
    return tot_size 

Also von dem, was ich verstanden habe ich die os.walk Funktion

import threedi_utils 

@mock.patch('threedi_utils.files.os.walk') 
def test_get_dir_size_can_get_dir_size(self, mock_walk): 
    mock_walk.return_value(5000) 
    size = threedi_utils.files.get_dir_size(self.test_path) 
    self.assertEqual(size, 5000) 

Aber mock_walk.return_value(5000) geht lustig zu machen, ohne Wirkung wie mein Test nicht

Traceback (most recent call last): 
    File "/home/vagrant/.buildout/eggs/mock-1.3.0-py2.7.egg/mock/mock.py", line 1305, in patched 
    return func(*args, **keywargs) 
    File "/srv/lib/threedi_utils/tests/test_files.py", line 55, in test_get_dir_size_can_get_dir_size 
    self.assertEqual(size, 5000) 
AssertionError: 0 != 5000 

Was bin ich mi Ssing?

Answer 1

Ok, ich war auf dem falschen Weg. Sollte die os.path.getsize() Methode verspottet haben. Außerdem muss der Rückgabewert wie folgt angegeben werden: .return_value = 5000

@mock.patch('threedi_utils.files.os.path.getsize') 
def test_get_dir_size_can_get_dir_size(self, mock_size): 
    mock_size.return_value = 50 
    size = threedi_utils.files.get_dir_size(self.test_path) 
    self.assertEqual(size, 750) 
    self.tearDown()