For this week, I wanted to look at how different languages handle test cases, and I’ll begin with the one I’m the most familiar with, Python! I’ve worked with Python in small amounts in the past, and have an understanding a lot of it’s syntaxes are similar to java’s, albeit simpler. I feel like this is a good topic to discuss as knowing how other programming languages handle unit testing would be a great way to expand my knowledge when it comes to furthering my understanding of it within Java.

For this, I’ll be looking at the official page for unittest on Python’s website, here:

https://docs.python.org/3/library/unittest.html

Right off the bat, I’m really interested in the fact that unittest is actually based directly off of JUnit! Which means a lot of the syntax, formatting, and framework is quite similar, just modified to fit the mold of Python.

Looking at the snippet they gave as an example…

import unittest

class TestStringMethods(unittest.TestCase):

    def test_upper(self):
        self.assertEqual('foo'.upper(), 'FOO')

    def test_isupper(self):
        self.assertTrue('FOO'.isupper())
        self.assertFalse('Foo'.isupper())

    def test_split(self):
        s = 'hello world'
        self.assertEqual(s.split(), ['hello', 'world'])
        # check that s.split fails when the separator is not a string
        with self.assertRaises(TypeError):
            s.split(2)

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

In this, it seems the way you define test blocks is by having a class with (unittest.testcase) and then doing “def” to define each test case.

Even the assertions are the same and written near identically, as the first three use assertEqual, which is identical to javas assertEquals, minus the s, and assertTrue and assertFalse, which are also identical to their java counterparts. assertRaises, which is used in the third test, seems to be Python’s equivalent to assertThrows, however, it seems to be a bit different in comparison. assertRaises seems to identify a specific kind of exception being raised, whereas assertThrows would just identify any exception in general.

The last line also is a block of code that allows an easy way to run all the tests, so when you run unittest.main() in a command line, it will automatically run all the tests and display the results.

There also seems to be a whole bunch of different command line options to display results and modify the ways in which its run. As an example, theres “-v”, which stands for verbosity, much like the bash command, which shows the results of each individual test being run, like below:

test_isupper (__main__.TestStringMethods.test_isupper) ... ok
test_split (__main__.TestStringMethods.test_split) ... ok
test_upper (__main__.TestStringMethods.test_upper) ... ok

----------------------------------------------------------------------
Ran 3 tests in 0.001s

OK

It seems extremely interesting and makes me want to learn more Python, which would definitely help me in my career in all sorts of ways! Next blog we will be looking at how unit testing works in C. Until then!

From the blog CS@Worcester – You're Telling Me A Shrimp Wrote This Code?! by tempurashrimple and used with permission of the author. All other rights reserved by the author.