How to fail a python unittest if the setUpClass throws exception

Question

I am having little trouble using the python setUpClass.

For example consider the following case

class MyTest(unittest.case.TestCase):

    @classmethod
          


        

Answer 1

use tearDownModule. It should be called after setUpClass runs.

Answer 2

You can call tearDownClass on an exception as Jeff points it out, but you may also implements the __del__(cls) method :

import unittest

class MyTest(unittest.case.TestCase):

    @classmethod
    def setUpClass(cls):
        print "Test setup"
        try:
            1/0
        except:
            raise

    @classmethod
    def __del__(cls):
        print "Test teardown"

    def test_hello(cls):
        print "Hello"

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

Will have the following output :

Test setup
E
======================================================================
ERROR: setUpClass (__main__.MyTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "my_test.py", line 8, in setUpClass
    1/0
ZeroDivisionError: integer division or modulo by zero

----------------------------------------------------------------------
Ran 0 tests in 0.000s

FAILED (errors=1)
Test teardown

Note : you should be aware that the __del__ method will be called at the end of the program execution, which is maybe not what you want if you have a more than one test class.

Hope it helps

Answer 3

import contextlib

class MyTestCase(unitest.TestCase):

    @classmethod
    def setUpClass(cls):
        with contextlib.ExitStack() as stack:
            # ensure teardown is called if error occurs
            stack.callback(cls.tearDownClass)

            # Do the things here!

            # remove callback at the end if no error found
            stack.pop_all()

Answer 4

The best option would be is to add handler for the except which calls tearDownClass and re-raise exception.

@classmethod
def setUpClass(cls):
    try:
        super(MyTest, cls).setUpClass()
        # setup routine...
    except Exception:  # pylint: disable = W0703
        super(MyTest, cls).tearDownClass()
        raise