def test_cart_article_listing(self):
        shopping_site = IShoppingSite(self.portal)
        self.assertEqual(shopping_site.cart_article_listing(), [])

        session = shopping_site.getSessionData(create=True)
        session.set('collective.cart.core', {'articles': {'1': 'ARTICLE1', '2': 'ARTICLE2'}})
        self.assertEqual(shopping_site.cart_article_listing(), ['ARTICLE1', 'ARTICLE2'])