When creating python unit tests you need to create a method in a unittest class. The problem however is when you don’t know until the code is running what these tests will be. In my particular case I need to run a series of tests against a number of Solaris packages. But I won’t know what the packages will be in advance.
Thankfully python allows to to add a method to a class on the fly:
>>> class test: ... pass ... >>> def foo(self): ... print "hello, world" ... >>> dir(test) ['__doc__', '__module__'] >>> test.foo=foo >>> dir(test) ['__doc__', '__module__', 'foo'] >>> bar=test() >>> bar.foo() hello, world >>>
Here we initially create an empty class ‘test’ and a function ‘foo’. Then add the function ‘foo’ to the class ‘test’, so that when we create a ‘test’ object, we can call the ‘foo’ method in it.
We use the same trick to add a unittest test to a unittest class:
>>> import unittest
>>> class mytest(unittest.TestCase):
... pass
...
>>> def test_testcase(self):
... self.assertEqual("hello","hello")
...
>>> suite = unittest.TestLoader().loadTestsFromTestCase(mytest)
>>> unittest.TextTestRunner(verbosity=2).run(suite)
----------------------------------------------------------------------
Ran 0 tests in 0.015s
OK
<unittest.runner.TextTestResult run=0 errors=0 failures=0>
>>> mytest.test_testcase=test_testcase
>>> unittest.TextTestRunner(verbosity=2).run(suite)
----------------------------------------------------------------------
Ran 0 tests in 0.000s
OK
<unittest.runner.TextTestResult run=0 errors=0 failures=0>
>>> suite = unittest.TestLoader().loadTestsFromTestCase(mytest)
>>> unittest.TextTestRunner(verbosity=2).run(suite)
test_testcase (__main__.mytest) ... ok
----------------------------------------------------------------------
Ran 1 test in 0.000s
OK
<unittest.runner.TextTestResult run=1 errors=0 failures=0>
>>>