Making your life exceptionally easier

exceptional.py

from functools import wraps


class NoExceptionRaisedError(Exception):
    pass


def exceptional(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        func(*args, **kwargs)
        raise NoExceptionRaisedError
    return wrapper


if __name__ == '__main__':
    import unittest

    class ReallyGoodExceptionError(Exception):
        pass

    @exceptional
    def good_function():
        raise ReallyGoodExceptionError('hello mother')

    @exceptional
    def bad_function():
        pass

    class ExceptionallyGoodTestCase(unittest.TestCase):
        def test_correct_function(self):
            with self.assertRaises(ReallyGoodExceptionError):
                good_function()

        def test_bad_function(self):
            with self.assertRaises(NoExceptionRaisedError):
                bad_function()

    unittest.main()