Python模拟补丁在另一个函数内的一个函数

Question

def f1():
    return 10, True

def f2():
    num, stat = f1()
    return 2*num, stat

我如何使用python的模拟库来修补f1()和返回自定义结果,以便我可以测试f2()？

编辑: 我的测试有问题吗？这似乎不起作用,所有测试都失败了AssertionError

from foo.bar import f2
from mock import patch

class MyTest(TestCase):

    def test_f2_1(self):
        with patch('project.module.f1') as some_func:
            some_func.return_value = (20, False)
            num, stat = f2()
            self.assertEqual((num, stat), (40, False))

   @patch('project.module.f1')
   def test_f2_2(self, some_func):
       some_func.return_value = (20, False)
       num, stat = f2()
       self.assertEqual((num, stat), (40, False))

Answer 1

第一个例子表明f1()和f2()在同一个模块中定义.因此以下应该有效:

from foo.bar import f2
from mock import patch

class MyTest(TestCase):

    @patch('foo.bar.f1')
    def test_f2_2(self, some_func):
        some_func.return_value = (20, False)
        num, stat = f2()
        self.assertEqual((num, stat), (40, False))

补丁与导入相同: @patch('foo.bar.f1')

这是一个很好的答案:

http://bhfsteve.blogspot.nl/2012/06/patching-tip-using-mocks-in-python-unit.html

Answer 2

假设你正在使用这个模拟库:

def f1():
    return 10, True

def f2():
    num, stat = f1()
    return 2*num, stat

import mock

print f2()   # Unchanged f1 -> prints (20, True)

with mock.patch('__main__.f1') as MockClass:       # replace f1 with MockClass 
    MockClass.return_value = (30, True)     # Change the return value

    print f2()     # f2 with changed f1 -> prints (60, True)

如果您的代码分为模块,则可能需要替换__main__.f1模块/功能的路径.