Question

我试图测试从我的一个打包对象中的函数调用回调。但是，mock.patch.object并不允许我从当前的测试用例中模拟一个函数。假设我有以下（简化）代码和测试：

import unittest
from six.moves import cStringIO
from mock import patch

class myclass(object):
    def __init__(self, callback):
        self.callback = callback

    def myfunc(key):
        self.callback(key)
        # other stuff with key

class MyTest(unittest.TestCase):
    def setUp(self):
        self.myobj = myobj(self._callback)
        self.cache_store = cStringIO()

    def _callback(self, key):
        self.cache_store.write(key)
        self.cache_store.seek(0)

    @patch.object('__main__.MyTest', '_callback')
    def test_callback_called(self, mock):
        self.myobj.myfunc("any string")
        self.assertTrue(mock.called)
        self.assertEqual(self.cache_store.read(), "any string")

我收到错误

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.4/dist-packages/mock/mock.py", line 1297, in patched
    arg = patching.__enter__()
  File "/usr/local/lib/python3.4/dist-packages/mock/mock.py", line 1369, in __enter__
    original, local = self.get_original()
  File "/usr/local/lib/python3.4/dist-packages/mock/mock.py", line 1343, in get_original
    "%s does not have the attribute %r" % (target, name)
AttributeError: __main__.MyTest does not have the attribute '_callback'

所以我的问题是：如何从当前的测试用例中模拟一个函数？

Answer 1

我找到了答案：在测试调用中使用patch.object作为上下文管理器。

Python单元测试和模拟：来自测试用例的模拟函数？

1 个答案: