我如何才能团结一致地只找到一次我的测试方法？

Question

I have a python unitest script with an double inheritance of the TestCase as follows:

import unittest
class Upper(unittest.TestCase):
    def test_dummy(self):
        pass

class Lower(Upper):
    pass

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

The idea is to define an upper class with a test method implementation, and derive from this class (in different subdirectories) which contain some additional setup functionality. In the end, there is one upper.py from which many different test_lower.py are derived. The test methods are ONLY implemented in upper.py .

Given the example above now I do a python test_example.py only to see that python is trying to run 2 tests! The script contains exactly one test, so why is unittest executing two tests?

I assume that unittest finds one test within Lower and one test in Upper somehow, but I only want to execute the test which is found in Lower (because of additional and required setup functionalities). How can I achieve this?

Context In the real case the two classes are defined in two different files, residing in two directories. Maybe this helps.

Answer 1

Unittest library iterates over a TestCase subclass attributes, finding methods which start with test_ . In case of Lower test case it inherits a method from its parent, so it is executed twice - once inside Upper test case and second time inside Lower class. If both of the test cases are meant to be run, the only solution i see is to make a take out test_dummy test to an other subclass of Upper

If you want a test to be run in a parent class, but skipped in some of its subclasses, try this:

import unittest
class Upper(unittest.TestCase):
    def test_dummy(self):
        pass

class Lower(Upper):
    def test_dummy(self):
        return  # skip test

    @unittest.skip  # or this - but ugly
    def test_dummy(self):
        return  # skip test

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

UPDATE:

I think now i understand what you want: you want the test method to be run only in subclasses. Then i suggest you to inherit Upper from object , and the subclasses - both from Upper and TestCase :

import unittest

class Upper(object):

    def test_dummy(self):
        self.assertTrue(True)

class Lower(unittest.TestCase, Upper):

    pass

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

Running:

python test2.py -v
test_dummy (__main__.Lower) ... ok

----------------------------------------------------------------------
Ran 1 test in 0.000s

OK