More Tips for Unit Testing in Iron Python

John E. Boal — Tue, 07 Oct 2008 16:09:49 GMT

Do you ever wonder why there is an extra "False" printed at the end of each run for unit tests?

C:\Code\sample>ipy UnitTests.py
.....
----------------------------------------------------------------------
Ran 5 tests in 0.395s

OK
False

It looks like there is an exit statement buried inside the unit test framework. We can eliminate the problem pretty easily with the addition of a try/except around the unit test execution. Here is the code to put at the end of your unit test script:

if __name__ == '__main__':
    try:
        unittest.main()
    except SystemExit:
        pass

This catches and eats the SystemExit exception, and runs without printing the "False" at the end of the execution:

C:\Code\sample>ipy UnitTests.py
.....
----------------------------------------------------------------------
Ran 5 tests in 0.387s

OK

cheers!

Unit Testing in Python

John E. Boal — Tue, 30 Sep 2008 13:26:26 GMT

I have been using IronPython lately, and am having a good time testing code with its built-in unit test framework. Here is a brief example of how to write some unit tests for IronPython (or CPython if that's your flavor). These unit tests leverage the "unittest" module available in Python 2.2 and above.

Here is a short test class:

class TestCode:
    localInt = 1
    @classmethod
    def Method1(self):
        return 100
    def Method2(self, a, b):
        self.localInt = a * b

Here are some sample unit tests for it, using the unittest framework:

import unittest
class UnitTests(unittest.TestCase):
    def testMethod1(self):
        cut = TestCode()
        actual = cut.Method1()
        self.assertEqual(100, actual)

def teststaticInt(self):
self.assertEqual(1, TestCode.localInt)

    def testMethod2(self):
        cut = TestCode()
        cut.Method2(7, 4)
        self.assertEqual(28, cut.localInt)

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

This example should illustrate that we can write some unit tests for our Python code fairly easily and quickly. It's nice to have a built-in framework for unit testing. There is also a "doctest" module available for doing more like system testing. I am pretty new to Python, so I haven't got examples of this as yet.

If anyone has any suggestions on tools or experience with integration with Visual Studio those comments would be appreciated.

Test Driven Developer - Python

More Tips for Unit Testing in Iron Python

Unit Testing in Python