python - 如何用 Mock 给 OS.mkdir 打补丁？

Question

我正在尝试使用 Mock 模块和 pytest 进行单元测试。

我希望 os.path.isdir() 返回 False，并且 os.mkdir() 不运行；我只想验证传递给它的参数是否正确。

我觉得你只需要看看set_path方法

我的应用:

import pytumblr, os, sys, prowlpy, json, collections
from urllib2 import urlopen
from time import sleep
from apiclient.discovery import build

class Site(object):
    """A generic site."""
    def __init__(self, user):
        self.user = user

    def set_path(self):
        if os.path.isdir(self.user_dir):            # if user dir already exists
            print "**Directory already exists: ", self.user_dir
        else:
            os.mkdir(self.user_dir)                 # else create user dir
            print "Created Directory: ", self.user_dir

class Tumblr(Site):
    """A tumblr blog."""
    type = "tumblr"
    type_dir = os.path.join(os.getcwd(), type)
    def __init__(self, user):
        super(Tumblr, self).__init__(user)
        self.user_dir = os.path.join(Tumblr.type_dir, self.user)

我的测试总是失败，如下所示:

import tumblrip_new as tum
import mock

    @mock.patch('tumblrip_new.os')
    @mock.patch('tumblrip_new.os.path')
    def test_create_new_user_dir(self, mock_path, mock_os):
        """Creates a directory if one does not exist."""
        t = tum.Tumblr("username")
        # directory does not exist:
        mock_path.isdir.return_value = False
        t.set_path()
        mock_os.mkdir.assert_called_with(t.user_dir)

输出显示失败的原因:

_mock_self = <MagicMock name='os.mkdir' id='33647664'>
args = (<MagicMock name='os.path.join()' id='33568048'>,), kwargs = {}
self = <MagicMock name='os.mkdir' id='33647664'>
expected = "mkdir(<MagicMock name='os.path.join()' id='33568048'>)"

>   ???
E   AssertionError: Expected call: mkdir(<MagicMock name='os.path.join()' id='3
568048'>)
E   Not called

build\bdist.win32\egg\mock.py:831: AssertionError
===================== 1 failed, 3 passed in 0.22 seconds ======================

Answer 1

我通过以下方式修复了它:

@mock.patch('tumblrip_new.os.path')
@mock.patch('tumblrip_new.os')
def test_create_new_user_dir(self, mock_os, mock_path):
    """Creates a directory if one does not exist."""
    t = tum.Tumblr("username")
    # directory does not exist:
    mock_path.isdir.return_value=False
    t.set_path()
    mock_os.mkdir.assert_called_with(t.user_dir)