Python unittest passing arguments

Question

In python how would I pass an argument from the command line to a unittest function. Here is the code so far… I know it\'s wrong.

class TestingClass(unittes         


        

Answer 1

Even if the test gurus say that we should not do it: I do. In some context it makes a lot of sense to have parameters to drive the test in the right direction, for example:

• which of the dozen identical USB cards should I use for this test now?
• which server should I use for this test now?
• which XXX should I use?

For me, the use of the environment variable is good enough for this puprose because you do not have to write dedicated code to pass your parameters around; it is supported by Python. It is clean and simple.

Of course, I'm not advocating for fully parametrizable tests. But we have to be pragmatic and, as I said, in some context you need a parameter or two. We should not abouse of it :)

import os
import unittest


class MyTest(unittest.TestCase):
    def setUp(self):
        self.var1 = os.environ["VAR1"]
        self.var2 = os.environ["VAR2"]

    def test_01(self):
        print("var1: {}, var2: {}".format(self.var1, self.var2))

Then from the command line (tested on Linux)

$ export VAR1=1
$ export VAR2=2
$ python -m unittest MyTest
var1: 1, var2: 2
.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK