Basic Python unittest TestSuite Question

问题:

Using Python 2.6, I have a very simple test in a python file in a directory:

#mytest.py import unittest  class BasicTests(unittest.TestCase):     def test_ok(self):         self.assertTrue(True)  suite = unittest.TestLoader().loadTestsFromTestCase(BasicTests) 

I change into the directory and run "python -m unittest mytest.suite" and I get the following error:

Traceback (most recent call last):   File "/usr/lib/python2.6/runpy.py", line 122, in _run_module_as_main     "__main__", fname, loader, pkg_name)   File "/usr/lib/python2.6/runpy.py", line 34, in _run_code     exec code in run_globals   File "/usr/lib/python2.6/unittest.py", line 875, in <module>     main(module=None)   File "/usr/lib/python2.6/unittest.py", line 816, in __init__     self.parseArgs(argv)   File "/usr/lib/python2.6/unittest.py", line 843, in parseArgs     self.createTests()   File "/usr/lib/python2.6/unittest.py", line 849, in createTests     self.module)   File "/usr/lib/python2.6/unittest.py", line 613, in loadTestsFromNames     suites = [self.loadTestsFromName(name, module) for name in names]   File "/usr/lib/python2.6/unittest.py", line 598, in loadTestsFromName     test = obj()   File "/usr/lib/python2.6/unittest.py", line 464, in __call__     return self.run(*args, **kwds) TypeError: run() takes exactly 2 arguments (1 given) 

I've tried several variations (such as unittest.makeSuite and unittest.LoadTestFromNames) but they all give me the same basic error. What am I missing? I keep reading the documentation and I seem to be following the spec.

回答1:

I don't usually work with unittest on the command line, but have my own test running scripts.

You need to add a function suite to the module

def suite():     return unittest.TestLoader().loadTestsFromTestCase(BasicTests) 

and then call it like "python -m unittest mytest.suite". But then I run into the following problem:

TypeError: calling <function suite at 0x00C1FB70> returned <unittest.TestSuite tests=[<mysite.BasicTests testMethod=test_ok>]>, not a test 

which happens because unittest uses something like isinstance(mytest.suite(), TestSuite) but through executing with "-m", you get two different versions of the TestSuite class (one is __main__.TestSuite, the other is unittest.TestSuite), so isinstance returns false.
To me, this looks like a bug. Patching unittest.py by inserting from unittest import TestSuite, TestCase at the beginning of loadTestsFromName solves the isinstance problem. Sorry I can't give you the "correct" solution (if there is one).

回答2:

Update: it looks like what I have above is in fact, correct. When I installed a copy of python2.7, everything worked fine. I dug through the unittest.py source code and found that this line of code was not working the way one would expect:

    elif isinstance(obj, TestSuite):         return obj     elif hasattr(obj, '__call__'):         test = obj() 

The first elif condition is failing, and thus it falls down into the one after where the exception is raised. I'm still not sure how that could even remotely happen - maybe a bad compilation - but I've gone ahead and filed a bug with the provider:

https://bugs.launchpad.net/ubuntu/+source/python2.6/+bug/726257

回答3:

You might want to try:

mytest.py:

import unittest  class BasicTests(unittest.TestCase):     def test_ok(self):         self.assertTrue(True)  if __name__ == '__main__':     unittest.sys.argv.insert(1,'--verbose')     unittest.main(argv = unittest.sys.argv)     

Then,

% python mytest.py 

runs all tests in all subclasses of TestCase, and

% python mytest.py BasicTests.test_ok 

runs just test_ok. This second form of the command is useful when you know there is a problem with one test and don't wish to run through every test.

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