Merge pull request #469 from edx/dcs/timed-exam-test

Ensure that timed exams do not attempt to update the backend

edx_proctoring/api.py

@@ -1069,10 +1069,13 @@ def update_attempt_status(exam_id, user_id, to_status,
 
     # call back to the backend to register the end of the exam, if necessary
     backend = get_backend_provider(exam)
-    if to_status == ProctoredExamStudentAttemptStatus.started:
-        backend.start_exam_attempt(exam['external_id'], attempt['external_id'])
-    if to_status == ProctoredExamStudentAttemptStatus.submitted:
-        backend.stop_exam_attempt(exam['external_id'], attempt['external_id'])
+    if backend:
+        # only proctored exams have a backend
+        # timed exams have no backend
+        if to_status == ProctoredExamStudentAttemptStatus.started:
+            backend.start_exam_attempt(exam['external_id'], attempt['external_id'])
+        if to_status == ProctoredExamStudentAttemptStatus.submitted:
+            backend.stop_exam_attempt(exam['external_id'], attempt['external_id'])
     # we user the 'status' field as the name of the event 'verb'
     emit_event(exam, attempt['status'], attempt=attempt)
 

edx_proctoring/backends/__init__.py

@@ -9,6 +9,10 @@ def get_backend_provider(exam=None):
     Returns an instance of the configured backend provider
     """
     backend_name = None
-    if exam and exam['backend']:
-        backend_name = exam['backend']
+    if exam:
+        if 'is_proctored' in exam and not exam['is_proctored']:
+            # timed exams don't have a backend
+            return None
+        elif exam['backend']:
+            backend_name = exam['backend']
     return apps.get_app_config('edx_proctoring').get_backend(name=backend_name)

edx_proctoring/backends/tests/test_backend.py

@@ -226,6 +226,17 @@ def test_backend_choices(self):
         ]
         self.assertEqual(choices, expected)
 
+    def test_no_backend_for_timed_exams(self):
+        """
+        Timed exams should not return a backend, even if one has accidentally been set
+        """
+        exam = {
+            'is_proctored': False,
+            'backend': 'test'
+        }
+        backend = get_backend_provider(exam)
+        self.assertIsNone(backend)
+
     def test_invalid_configurations(self):
         """
         Test that invalid backends throw the right exceptions

edx_proctoring/tests/test_views.py

@@ -2503,6 +2503,7 @@ def test_launch_for_course(self):
             external_id='123aXqe3',
             time_limit_mins=90,
             is_active=True,
+            is_proctored=True,
         )
 
         expected_url = '/instructor/%s/' % course_id
@@ -2521,6 +2522,7 @@ def test_launch_for_exam(self):
             external_id='123aXqe3',
             time_limit_mins=90,
             is_active=True,
+            is_proctored=True,
         )
         exam_id = proctored_exam.id
 
@@ -2540,6 +2542,7 @@ def test_error_with_multiple_backends(self):
             external_id='123aXqe3',
             time_limit_mins=90,
             is_active=True,
+            is_proctored=True,
             backend='test',
         )
         ProctoredExam.objects.create(
@@ -2549,6 +2552,7 @@ def test_error_with_multiple_backends(self):
             external_id='123aXqe4',
             time_limit_mins=90,
             is_active=True,
+            is_proctored=True,
             backend='null',
         )
         response = self.client.get(