使用 Python 2.7 和模拟库
我如何使用 mock 测试某个修补对象是否已使用某些特定参数进行了初始化?
这里有一些示例代码和伪代码:
单元测试.py:
import mock
@mock.patch('mylib.SomeObject')
def test_mytest(self, mock_someobject):
test1 = mock_someobject.return_value
test1 = method_inside_someobject.side_effect = ['something']
mylib.method_to_test()
# How can I assert that method_to_test instanced SomeObject with certain arguments?
# I further test things with that method_inside_someobject call, no problems there...
我的库文件:
from someobjectmodule import SomeObject
def method_to_test():
obj = SomeObject(arg1=val1, arg2=val2, arg3=val3)
obj.method_inside_someobject()
那么,我如何测试 SomeObject 是使用 arg1=val1、arg2=val2、arg3=val3 实例化的?
最佳答案
如果你用模拟替换了一个类,那么创建一个实例只是另一个调用。断言已将正确的参数传递给该调用,例如 mock.assert_called_with()
:
mock_someobject.assert_called_with(arg1=val1, arg2=val2, arg3=val3)
为了说明,我已将您的 MCVE 更新为一个工作示例:
测试.py:
import mock
import unittest
import mylib
class TestMyLib(unittest.TestCase):
@mock.patch('mylib.SomeObject')
def test_mytest(self, mock_someobject):
mock_instance = mock_someobject.return_value
mock_instance.method_inside_someobject.side_effect = ['something']
retval = mylib.method_to_test()
mock_someobject.assert_called_with(arg1='foo', arg2='bar', arg3='baz')
self.assertEqual(retval, 'something')
if __name__ == '__main__':
unittest.main()
mylib.py:
from someobjectmodule import SomeObject
def method_to_test():
obj = SomeObject(arg1='foo', arg2='bar', arg3='baz')
return obj.method_inside_someobject()
someobjectmodule.py:
class SomeObject(object):
def method_inside_someobject(self):
return 'The real thing'
并运行测试:
$ python test.py
.
----------------------------------------------------------------------
Ran 1 test in 0.001s
OK
关于Python模拟对象实例化,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35803914/