Possible Duplicate:
How do you generate dynamic (parameterized) unit tests in Python?
I have a function to test, under_test, and a set of expected input/output pairs:
[
(2, 332),
(234, 99213),
(9, 3),
# ...
]
I would like each one of these input/output pairs to be tested in its own test_* method. Is that possible?
This is sort of what I want, but forcing every single input/output pair into a single test:
class TestPreReqs(unittest.TestCase):
def setUp(self):
self.expected_pairs = [(23, 55), (4, 32)]
def test_expected(self):
for exp in self.expected_pairs:
self.assertEqual(under_test(exp[0]), exp[1])
if __name__ == '__main__':
unittest.main()
(Also, do I really want to be putting that definition of self.expected_pairs in setUp?)
UPDATE: Trying doublep's advice:
class TestPreReqs(unittest.TestCase):
def setUp(self):
expected_pairs = [
(2, 3),
(42, 11),
(3, None),
(31, 99),
]
for k, pair in expected_pairs:
setattr(TestPreReqs, 'test_expected_%d' % k, create_test(pair))
def create_test (pair):
def do_test_expected(self):
self.assertEqual(get_pre_reqs(pair[0]), pair[1])
return do_test_expected
if __name__ == '__main__':
unittest.main()
This does not work. 0 tests are run. Did I adapt the example incorrectly?
Not tested:
class TestPreReqs(unittest.TestCase):
...
def create_test (pair):
def do_test_expected(self):
self.assertEqual(under_test(pair[0]), pair[1])
return do_test_expected
for k, pair in enumerate ([(23, 55), (4, 32)]):
test_method = create_test (pair)
test_method.__name__ = 'test_expected_%d' % k
setattr (TestPreReqs, test_method.__name__, test_method)
If you use this often, you could prettify this by using utility functions and/or decorators, I guess. Note that pairs are not an attribute of TestPreReqs object in this example (and so setUp is gone). Rather, they are "hardwired" in a sense to the TestPreReqs class.