如何在setUpClass中使python单元测试失败？

Question

I am doing some unittests with python and some pre-test checks in setUpClass . How can I throw a unitest - fail within the setUpClass , as the following simple example:

class MyTests(unittest.TestCase):

    @classmethod
    def setUpClass(cls):    
        unittest.TestCase.fail("Test")

    def test1(self):
        pass

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

gives the error TypeError: unbound method fail() must be called with TestCase instance as first argument (got str instance instead) .

I understand the error I get as fail is a instance method, and I don't have an instance of MyClass yet. Using an instance on-the-fly like

unittest.TestCase().fail("Test")

also does not work, as unittest.TestCase itself has no tests. Any ideas how to fail all tests in MyClass , when some condition in setUpClass is not met?

Followup question: Is there a way to see the tests in setUpClass ?

Answer 1

self.fail("test") put into your setUp instance method fails all the tests

I think the easiest way to do this at the class level is to make a class variable so something like:

@classmethod
def setUpClass(cls):
   cls.flag = False

def setUp(self):
   if self.flag:
       self.fail("conditions not met")

Hope this is what you want.

Answer 2

使用简单的断言应该有效

assert False, "I mean for this to fail"