Selenium Unit Test Reuse

Yesterday, one of the QA guys at work approached me with a question that turned out to be much more interesting to me than I think he had planned. He's been doing some unit testing using Selenium, exporting his test cases to Python. His question was this: how can I run the same unit tests using multiple browsers and multiple target servers?

I'm pretty sure he expected a simple 3-step answer or something like that. Instead, he got my crazy wide-eyed "ohhh... that's something I want to experiment with!" look. I started rambling on about inheritance, dynamic class creation, and nested for loops. His eyes started to look a little worried. He didn't really appreciate the nerdy lingo that much. I told him to pull up a chair and get comfortable.

Since I already had some other work I needed to pay attention to, I didn't want to spend too much time trying to figure out a good way to solve his problem. After about 20 minutes of devilish chuckles and frantic rustling through Python documentation, I came up with the following code:

from types import ClassType
from selenium import selenium
import unittest

IPS = ['192.168.0.1', '192.168.0.2']
BROWSERS = ['safari', 'chrome']

class SomeUnitTest(object):

    def test_something(self):
        sel = self.selenium
        # test code

def main(base):
    suites = []
    results = unittest.TestResult()

    for iidx, ip in enumerate(IPS):
        for bidx, browser in enumerate(BROWSERS):
            def setUp(self):
                self.verificationErrors = []
                self.selenium = selenium("localhost", 4444, "*%s" % self.browser, "http://%s/" % self.ip)
                self.selenium.start()

            def tearDown(self):
                self.selenium.stop()
                self.assertEqual([], self.verificationErrors)

            ut = ClassType('UT_%i_%i' % (iidx, bidx), (unittest.TestCase, base), {'ip': ip, 'browser': browser})
            ut.setUp = setUp
            ut.tearDown = tearDown

            suites.append(unittest.TestLoader().loadTestsFromTestCase(ut))

    unittest.TestSuite(suites)(results)
    for obj, error in results.errors:
        print 'In: ', obj
        print error

if __name__ == "__main__":
    main(SomeUnitTest)

I know, I know... it's got some dirty rotten tricks in it, and there are probably more efficient ways of doing what I've done. If the code offends you, look up at my previous disclaimer: I had other things I needed to be working on, so I didn't spend much time refining this. One thing I'm almost certain could be done better is not monkey patching the dynamic classes with the setUp and tearDown methods. Also, the output at the end of the test execution could definitely use some love. Oh well. Perhaps another day I'll get around to that.

Basically, you just set the servers you need to test and the browsers you want Selenium to run the tests in. Those are at the top of the script: IPS and BROWSERS. Then a new unittest.TestCase class is created for each combination of IP/server+browser. Finally, each of the test cases is thrown into a TestSuite, and the suite is processed. If there were any errors during the tests, they'll be printed out. We weren't really concerned with printing out other information, but you can certainly make other meaningful feedback appear.

Anyway, I thought that someone out there might very well benefit from my little experiment on my co-worker's question. Feel free to comment on your personal adventures with some variation of the code if you find it useful!