Testing Python Decorators?

Question

I'm writing some unit tests for a Django project, and I was wondering if its possible (or necessary?) to test some of the decorators that I wrote for it.

Here is an example of a decorator that I wrote:

class login_required(object):      def __init__(self, f):         self.f = f      def __call__(self, *args):         request = args[0]         if request.user and request.user.is_authenticated():             return self.f(*args)         return redirect('/login') 

Answer 1

Simply:

from nose.tools import assert_equal from mock import Mock  class TestLoginRequired(object):     def test_no_user(self):         func = Mock()         decorated_func = login_required(func)         request = prepare_request_without_user()         response = decorated_func(request)         assert not func.called         # assert response is redirect      def test_bad_user(self):         func = Mock()         decorated_func = login_required(func)         request = prepare_request_with_non_authenticated_user()         response = decorated_func(request)         assert not func.called         # assert response is redirect      def test_ok(self):         func = Mock(return_value='my response')         decorated_func = login_required(func)         request = prepare_request_with_ok_user()         response = decorated_func(request)         func.assert_called_with(request)         assert_equal(response, 'my response') 

The mock library helps here.