Add test for process_postback with extras

Author: Grace Yim

test/test_toopher_iframe.py

@@ -106,6 +106,10 @@ def test_process_postback_good_signature_returns_user(self):
         self.assertEqual(user.name, 'user name')
         self.assertTrue(user.toopher_authentication_enabled)
 
+    def test_process_postback_good_signature_with_extras_returns_authentication_request(self):
+        auth_request = self.iframe_api.process_postback(self._get_urlencoded_auth_request_postback_data(), ToopherIframeTests.request_token, ttl=100)
+        self.assertEqual(type(auth_request), toopher.AuthenticationRequest)
+
     def test_process_postback_bad_signature_fails(self):
         data = self._get_auth_request_postback_data_as_dict()
         data['toopher_sig'] = 'invalid'