fix: exam start time reset (#314)

edx_exams/apps/core/api.py

@@ -99,8 +99,11 @@ def update_attempt_status(attempt_id, to_status):
  if not allowed_to_start:
  raise ExamIllegalStatusTransition(error_msg)
 
- attempt_obj.start_time = datetime.now(pytz.UTC)
- attempt_obj.allowed_time_limit_mins = _calculate_allowed_mins(attempt_obj.user, attempt_obj.exam)
+ # Once start time, and end time by extension, has been set further transitions to started
+ # must not update this value
+ if not attempt_obj.start_time:
+ attempt_obj.start_time = datetime.now(pytz.UTC)
+ attempt_obj.allowed_time_limit_mins = _calculate_allowed_mins(attempt_obj.user, attempt_obj.exam)
 
  course_key = CourseKey.from_string(attempt_obj.exam.course_id)
  usage_key = UsageKey.from_string(attempt_obj.exam.content_id)

edx_exams/apps/core/tests/test_api.py

@@ -407,6 +407,21 @@ def test_cannot_start_if_other_attempts_active(self):
  update_attempt_status(self.exam_attempt.id, ExamAttemptStatus.started)
  self.assertIn('another exam attempt is currently active!', str(exc.exception))
 
+ def test_ready_to_submit_to_started(self):
+ """
+ Test transition to started after initial start time has been set. This should not
+ alter the existing start time.
+ """
+ with freeze_time(timezone.now()):
+ self.exam_attempt.status = ExamAttemptStatus.ready_to_submit
+ self.exam_attempt.start_time = timezone.now()-timedelta(minutes=10)
+ self.exam_attempt.allowed_time_limit_mins = 30
+ self.exam_attempt.save()
+
+ update_attempt_status(self.exam_attempt.id, ExamAttemptStatus.started)
+ self.exam_attempt.refresh_from_db()
+ self.assertEqual(self.exam_attempt.start_time, timezone.now()-timedelta(minutes=10))
+
 
 class TestGetAttemptById(ExamsAPITestCase):
  """