Add log separators to all fixtures in unittests

Question

I'm using unittest module. I need to separate setUp, setUpClass, teardown and teardownClass logs from unittests logs. Output should look something like:

**************setting things up**************
INFO: preparing database
INFO: create new users
**************end of setup****************
INFO: starting test one
INFO: ...
**************Cleaning things**************
INFO: delete users
...

I tried to override some functions in unittest.suite (_handleClassSetUp, _handleModuleFixtures, _tearDownPreviousClass) to log separators before and after they are called. As a result separators are logged even if test case does not contain setUpClass and tearDownClass. And still, there is no separator for setup and teardown.

How can it be done?

Answer 1

You could use a metaclass to achieve this functionality. All it's doing is looking for a list of function names that you provide, and then applying a decorator to those functions. The decorator handles printing entry and exit statements.

import functools
import unittest

FUNCTIONS_TO_LOG = ('setUp', 'tearDown')


def log_start_and_end(f):
    @functools.wraps(f)
    def wrapper(*args, **kwargs):
        print '********** start {}'.format(f.__name__)
        f(*args, **kwargs)
        print '********** end {}'.format(f.__name__)
    return wrapper


class LoggingMeta(type):
    def __new__(cls, name, bases, namespace):
        for attr, obj in namespace.items():
            if attr in FUNCTIONS_TO_LOG:
                namespace[attr] = log_start_and_end(obj)
        return super(LoggingMeta, cls).__new__(cls, name, bases, namespace)


class BaseTest(unittest.TestCase):
    __metaclass__ = LoggingMeta

    def setUp(self):
        print 'inside setup'

    def tearDown(self):
        print 'inside teardown'

    def test_test(self):
        print 'inside test'

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

This results in output:

********** start setUp
inside setup
********** end setUp
inside test
********** start tearDown
inside teardown
********** end tearDown
.

---

Ran 1 test in 0.000s

OK