谁能告诉我为什么这行不通?
>>> import mock
>>> @mock.patch('datetime.date.today')
... def today(cls):
... return date(2010, 1, 1)
...
>>> from datetime import date
>>> date.today()
datetime.date(2010, 12, 19)
也许有人能提出一个更好的办法?
谁能告诉我为什么这行不通?
>>> import mock
>>> @mock.patch('datetime.date.today')
... def today(cls):
... return date(2010, 1, 1)
...
>>> from datetime import date
>>> date.today()
datetime.date(2010, 12, 19)
也许有人能提出一个更好的办法?
当前回答
我通过将datetime导入为realdatetime并将我在模拟中需要的方法替换为实际方法来完成这项工作:
import datetime as realdatetime
@mock.patch('datetime')
def test_method(self, mock_datetime):
mock_datetime.today = realdatetime.today
mock_datetime.now.return_value = realdatetime.datetime(2019, 8, 23, 14, 34, 8, 0)
其他回答
值得注意的是,Mock文档专门讨论了datetime.date.today,并且可以在不创建虚拟类的情况下做到这一点:
https://docs.python.org/3/library/unittest.mock-examples.html#partial-mocking
>>> from datetime import date
>>> with patch('mymodule.date') as mock_date:
... mock_date.today.return_value = date(2010, 10, 8)
... mock_date.side_effect = lambda *args, **kw: date(*args, **kw)
...
... assert mymodule.date.today() == date(2010, 10, 8)
... assert mymodule.date(2009, 6, 8) == date(2009, 6, 8)
...
对我来说最简单的方法是:
import datetime
from unittest.mock import Mock, patch
def test():
datetime_mock = Mock(wraps=datetime.datetime)
datetime_mock.now.return_value = datetime.datetime(1999, 1, 1)
with patch('datetime.datetime', new=datetime_mock):
assert datetime.datetime.now() == datetime.datetime(1999, 1, 1)
注意:target_module中的datetime模块中的所有功能都将停止工作。
可以在不添加side_effects的情况下模拟datetime模块中的函数
import mock
from datetime import datetime
from where_datetime_used import do
initial_date = datetime.strptime('2018-09-27', "%Y-%m-%d")
with mock.patch('where_datetime_used.datetime') as mocked_dt:
mocked_dt.now.return_value = initial_date
do()
对我来说,最好的方法是结合@Daniel G和@frx08的解决方案:
class Test_mock_date:
class NewDate(datetime.datetime):
@classmethod
def now(cls, tz=None):
return cls(2021, 5, 12)
def test_mock_date(self):
with patch('datetime.datetime', new = self.NewDate):
assert datetime.datetime.now() == datetime.datetime(2021, 5, 12, 0, 0)
你可以看看下面我写的关于如何使用MagicMock的不同示例的中型文章https://medium.com/@camposer/d2113513b365
对于那些在测试类中使用补丁程序的人,下面是我如何成功地修补datetime功能:
from datetime import datetime
import unittest
from unittest.mock import Mock, patch
# Replace with the proper path to the module you would
# like datetime to be mocked
from path.to.my_module
class MyTestCases(unittest.TestCase):
def setUp(self):
"""execute on class instantiation"""
# Record both times at the same moment
self.dt_now, self.dt_utcnow = datetime.now(), datetime.utcnow()
# After retrieving real (or hardcoded datetime values),
# proceed to mock them in desired module
self.patch_datetime_functions()
def patch_datetime_functions(self) -> None:
"""
Patch datetime.now() and datetime.utcnow() to prevent issues when
comparing expected dates
"""
# Create a patcher
self.patcher_dt = patch(
'path.to.my_module'
)
# Start but make sure cleanup always occurs
self.patcher_dt.start()
self.addCleanup(self.patcher_dt.stop)
# Perform the actual patch – use lambdas as mock functions
datetime_mock = Mock(wraps=datetime)
datetime_mock.now.return_value = self.dt_now
datetime_mock.utcnow.return_value = self.dt_utcnow
my_module.datetime = datetime_mock
# Here's what it will look like when testing:
def some_test(self):
curr_dt = self.dt_now
returned_dt = my_module.datetime.utcnow()
# Compare the dates
self.assertEqual(curr_dt, returned_dt,
'Datetime values should be equal'
)