使用unittest.mock.patch全局模拟方法

Question

我试图模拟由另一个模块中的另一个方法调用的方法。具体来说，我希望将bar.py中对foo的调用替换为对mock_foo的调用:

foo.py

def foo():
return 'foo'

bar.py

from foo import foo
def bar.py():
return foo()

test.py

from bar import bar
def mock_foo():
return 'mock_foo'
def testmethod():
with patch('foo.foo', mock_foo):
print(bar())  
# Expected output:'mock_foo'

上面的patch方法不起作用。这可以用模拟库做到吗?如果是，我应该如何修改test.py?

Answer 1

应该修补在bar模块内导入的foo函数。所以，目标应该是bar.foo。

。

foo.py:

def foo():
return 'foo'

bar.py:

from foo import foo

def bar():
return foo()

test_bar.py:

from bar import bar
import unittest
from unittest.mock import patch

def mock_foo():
return 'mock_foo'

class BarTest(unittest.TestCase):
def test_bar(self):
with patch('bar.foo', mock_foo):
print(bar())
self.assertEqual(bar(), 'mock_foo')

if __name__ == '__main__':
unittest.main()

单元测试结果:

⚡  coverage run /Users/dulin/workspace/github.com/mrdulin/python-codelab/src/stackoverflow/66540831/test_bar.py && coverage report -m --include './src/**'
mock_foo
.
----------------------------------------------------------------------
Ran 1 test in 0.000s
OK
Name                                     Stmts   Miss  Cover   Missing
----------------------------------------------------------------------
src/stackoverflow/66540831/bar.py            3      0   100%
src/stackoverflow/66540831/foo.py            2      1    50%   2
src/stackoverflow/66540831/test_bar.py      12      0   100%
----------------------------------------------------------------------
TOTAL                                       17      1    94%