dynamic unittest

**Peter Otten** · Jul 17 '06, 06:45 AM

Re: dynamic unittest

Oleg Paraschenko wrote:

Hello,
>
I decided to re-use functionality of "unittest" module for my purposes.
More precisely, I have a list of folders. For each folder, code should
enter to the folder, execute a command and assert the output. It's
reasonable to use "unittest" here, but the problem is that "unittest"
doesn't support (== I haven't found how) dynamic creation of tests.
>
I thought it would be very easy, but due to lack of closures in Python
(more precisely, closures do exist, but they are counter-intuitive for
lisp programmers), I failed. Finally, I found a way using a global
variable. I exploit the fact that "unittest" uses "cmp" to arrange test
cases. Therefore, if we have an array of test names and sequential
number of running the common function, we know the name of the current
test. Here is a sample code:
>
------- <dynamic_unitte st.py>
>
import sys, unittest
test_names = ['aaa', 'ddd', 'bbb']
test_names.sort ()
test_index = 0
>
class DynamicTestCase (unittest.TestC ase):
def one_test(self):
global test_index
test_name = test_names[test_index]
test_index = test_index + 1
# Ok for 'aaa' and 'bbb', failure for 'ddd'
assert test_name in ['aaa', 'bbb']
>
for test_name in test_names:
func_name = 'test_' + test_name
setattr(Dynamic TestCase, func_name, DynamicTestCase .one_test)
>
suite = unittest.makeSu ite(DynamicTest Case, 'test_')
if not unittest.TextTe stRunner().run( suite).wasSucce ssful():
sys.exit(1)
>
------- </dynamic_unittes t.py>
>
I think this code might help others, so I post it to the group.
Comments are welcome.

Here's what your code might look like with closures:

import sys
import unittest

test_names = ['aaa', 'ddd', 'bbb']
test_names.sort ()

class DynamicTestCase (unittest.TestC ase):
pass

def make_test(test_ name):
def one_test(self):
self.assert_(te st_name in ['aaa', 'bbb'])
return one_test

for test_name in test_names:
setattr(Dynamic TestCase, 'test_' + test_name, make_test(test_ name))

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

Peter

**Oleg Paraschenko** · Jul 17 '06, 01:55 PM

Re: dynamic unittest

Hello Peter,

thanks a lot. I've overlooked this simple way to create the right
closure.

--
Oleg