所以我正在练习一些单元测试,并试图检查for循环中的输出。这是我的运行代码
def main():
for i in range(100):
print("Argh!")
非常基本,现在是我的测试代码。
import unittest
from unittest import mock # possibly "from unittest import mock" depending on version.
from RunFile import main
class TestMain(unittest.TestCase):
def test_main(self):
with mock.patch.object(main(), 'print') as mock_print:
main()
expected_calls = [mock.call('Argh!') for _ in range(100)]
mock_print.assert_has_calls(expected_calls)
if __name__ == '__main__':
unittest.main()
这是我收到的错误信息。我不知道如何解决这个问题。更新:这是完整的追溯
======================================================================
ERROR: test_main (__main__.TestMain)
----------------------------------------------------------------------
Traceback (most recent call last):
File "C:/Users/jsalce/Documents/Testsuites/IfStatements/Testsuite.py", line 9, in test_main
with mock.patch.object(RunFile, 'print') as mock_print:
File "C:Python33libunittestmock.py", line 1148, in __enter__
original, local = self.get_original()
File "C:Python33libunittestmock.py", line 1122, in get_original
"%s does not have the attribute %r" % (target, name)
AttributeError: <module 'RunFile' from 'C:\Users\jsalce\Documents\Testsuites\IfStatements\RunFile.py'> does not have the attribute 'print'
----------------------------------------------------------------------
Ran 1 test in 0.001s
FAILED (errors=1)
提前感谢大家!
一般来说,对于mock.patch.object
,您希望修补一些您可以轻松处理的东西,例如模块或类。通常,你需要修补比你想要替换的东西高一级的东西。例如,如果要修补模块bar
中的foo
函数,则需要mock.patch.object(bar, 'foo')
。
在您的案例中,从技术上讲,print
是builtin
,但您可以在使用它的模块上对其进行修补。这将添加一个RunFile.print
"方法"(实际上是一个mock),您可以针对它测试断言。显然,由于模块上实际上并不存在print
,我们需要添加create=True
来告诉mock
创建RunFile.print
,因为它还不存在。考虑到这一点,我会将单元测试重写为:
import RunFile
class TestMain(unittest.TestCase):
def test_main(self):
with mock.patch.object(RunFile, 'print', create=True) as mock_print:
RunFile.main()
expected_calls = [mock.call('Argh!') for _ in range(100)]
mock_print.assert_has_calls(expected_calls)
if __name__ == '__main__':
unittest.main()