python - 将 Python 3 ResourceWarnings 转换为异常

Question

有没有办法强制 Python 3 单元测试失败，而不是简单地向 stderr 打印警告，如果它导致任何 ResourceWarning？

我试过以下方法:

import warnings
warnings.simplefilter(action='error', category=ResourceWarning)

这导致单元测试的输出:

my_test (__main__.MyTest) ... Exception ignored in: <socket.socket fd=9, family=AddressFamily.AF_INET, type=SocketType.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 54065), raddr=('127.0.0.1', 27017)>
ResourceWarning: unclosed <socket.socket fd=9, family=AddressFamily.AF_INET, type=SocketType.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 54065), raddr=('127.0.0.1', 27017)>
ok

----------------------------------------------------------------------
Ran 1 test in 0.110s

注意“忽略异常”消息。我宁愿测试失败，也不要要求我阅读其输出以查找 ResourceWarnings。

Answer 1

这是一个单元测试，如果 ResourceWarning 是由 with catch_warning() 语句生成的:

#!/usr/bin/env python3
import gc
import socket
import unittest
import warnings

class Test(unittest.TestCase):
    def test_resource_warning(self):
        s = socket.socket()
        ####s.close() #XXX uncomment to pass the test

        # generate resource warning when s is deleted
        with warnings.catch_warnings(record=True) as w:
            warnings.resetwarnings() # clear all filters
            warnings.simplefilter('ignore') # ignore all
            warnings.simplefilter('always', ResourceWarning) # add filter
            del s        # remove reference
            gc.collect() # run garbage collection (for pypy3)
            self.assertFalse(w and str(w[-1])) # test fails if there
                                               # are warnings

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