class NextPreviousMonthViewTests(TestCase):
    urls = 'regressiontests.generic_views.urls'

    def setUp(self):
        self.pubdate_list = [
            datetime.date(2010, month, day)
            for month,day in ((9,1), (10,2), (11,3))
        ]
        for pubdate in self.pubdate_list:
            name = str(pubdate)
            Book.objects.create(name=name, slug=name, pages=100, pubdate=pubdate)

    def test_previous_month_bug(self):
        res = self.client.get('/dates/books/2010/nov/allow_empty/')
        self.assertEqual(res.status_code, 200)
        self.assertEqual(res.context['previous_month'], datetime.date(2010,10,1))
        # The following test demonstrates the bug
        res = self.client.get('/dates/books/2010/nov/')
        self.assertEqual(res.status_code, 200)
        self.assertEqual(res.context['previous_month'], datetime.date(2010,10,1))
        # The bug does not occur here because a Book with pubdate of Sep 1 exists
        res = self.client.get('/dates/books/2010/oct/')
        self.assertEqual(res.status_code, 200)
        self.assertEqual(res.context['previous_month'], datetime.date(2010,9,1))