id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	notify_on_close	platform	project
1081	Bug in unit testing	Tristan Croll	Conrad Huang	"Not sure why I was suddenly hit with this, other than that I'm currently cleaning out obsolete/duplicate code. In any case, I suddenly started hitting the following traceback in `make app-install`

{{{
  File ""/home/tic20/apps/chimerax/lib/python3.6/site-packages/setuptools/command/test.py"", line 67, in loadTestsFromModule
    def __init__(self, fget):
  File ""/home/tic20/apps/chimerax/lib/python3.6/unittest/suite.py"", line 24, in __init__
    self.addTests(tests)
  File ""/home/tic20/apps/chimerax/lib/python3.6/unittest/suite.py"", line 60, in addTests
    self.addTest(test)
  File ""/home/tic20/apps/chimerax/lib/python3.6/unittest/suite.py"", line 47, in addTest
    raise TypeError(""{} is not callable"".format(repr(test)))
TypeError: None is not callable
}}}

After some digging, this seems to boil down to a clear bug in unittest that occurs if/when a submodule is traversed more than once. In `site-packages/setuptools/command` at line 26:

{{{
    def loadTestsFromModule(self, module, pattern=None):
        """"""Return a suite of all tests cases contained in the given module

        If the module is a package, load tests from all the modules in it.
        If the module has an ``additional_tests`` function, call it and add
        the return value to the tests.
        """"""
        if module in self._visited:
            return None
        self._visited.add(module)
}}} 

The `None` gets carried through, until in `unittest/suite.py` it finally breaks:

{{{
    def addTest(self, test):
        # sanity checks
        if not callable(test):
            raise TypeError(""{} is not callable"".format(repr(test)))
        if isinstance(test, type) and issubclass(test,
                                                 (case.TestCase, TestSuite)):
            raise TypeError(""TestCases and TestSuites must be instantiated ""
                            ""before passing them to addTest()"")
        self._tests.append(test)
}}}

I think the easy monkeypatch would be to add

{{{
    if test is None:
        return
}}}

at the beginning of addtest().

What beats me is: why hasn't this been hitting everyone?"	defect	closed	moderate		Tool Shed		not a bug						all	ChimeraX