Gracefully handle peer assessing before submitting a response

apps/openassessment/xblock/peer_assessment_mixin.py

@@ -57,6 +57,9 @@ class PeerAssessmentMixin(object):
         if 'criterion_feedback' not in data:
             return {'success': False, 'msg': _('Must provide feedback for criteria in the assessment')}
 
+        if self.submission_uuid is None:
+            return {'success': False, 'msg': _('You must submit a response before you can peer-assess.')}
+
         assessment_ui_model = self.get_assessment_module('peer-assessment')
         if assessment_ui_model:
             rubric_dict = {

apps/openassessment/xblock/test/test_peer.py

@@ -83,6 +83,13 @@ class TestPeerAssessment(XBlockHandlerTestCase):
             "Hal".encode('utf-8') in peer_response.body)
 
     @scenario('data/peer_assessment_scenario.xml', user_id='Bob')
+    def test_peer_assess_before_submission(self, xblock):
+        # Submit a peer assessment without a submission
+        resp = self.request(xblock, 'peer_assess', json.dumps(self.ASSESSMENT), response_format='json')
+        self.assertEqual(resp['success'], False)
+        self.assertGreater(len(resp['msg']), 0)
+
+    @scenario('data/peer_assessment_scenario.xml', user_id='Bob')
     def test_missing_keys_in_request(self, xblock):
         for missing in ['criterion_feedback', 'overall_feedback', 'options_selected']:
             assessment = copy.deepcopy(self.ASSESSMENT)