feat: calculate exam time with allowances (#290)

edx_exams/apps/api/v1/tests/test_views.py

@@ -1634,6 +1634,20 @@ def test_no_active_attempt(self):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response_exam, expected_data)
 
+    def test_user_has_allowance(self):
+        """
+        Test that if user has an allowance, the total time is calculated correctly
+        """
+        StudentAllowanceFactory.create(
+            user=self.user,
+            exam=self.exam,
+            extra_time_mins=30
+        )
+
+        response = self.get_api(self.user, self.course_id, self.content_id)
+        response_exam = response.data['exam']
+        self.assertEqual(response_exam['total_time'], self.exam.time_limit_mins + 30)
+
     def test_active_attempt(self):
         """
         Test that if attempt exists, it is returned as part of the exam object

edx_exams/apps/api/v1/views.py

@@ -711,20 +711,26 @@ def get(self, request, course_id, content_id):  # pylint: disable=unused-argumen
             return Response(data)
 
         serialized_exam = ExamSerializer(exam).data
+        allowance = StudentAllowance.get_allowance_for_user(request.user.id, exam.id)
 
         exam_type_class = get_exam_type(exam.exam_type)
 
         # the following are additional fields that the frontend expects
         serialized_exam['type'] = exam.exam_type
         serialized_exam['is_proctored'] = exam_type_class.is_proctored
         serialized_exam['is_practice_exam'] = exam_type_class.is_practice
-        # total time is equivalent to time_limit_mins for now because allowances are not yet supported
-        serialized_exam['total_time'] = exam.time_limit_mins
         # timed exams will have None as a backend
         serialized_exam['backend'] = exam.provider.verbose_name if exam.provider is not None else None
 
         serialized_exam['passed_due_date'] = is_exam_passed_due(serialized_exam)
+
+        if allowance is not None:
+            serialized_exam['total_time'] = exam.time_limit_mins + allowance.extra_time_mins
+        else:
+            serialized_exam['total_time'] = exam.time_limit_mins
+
         exam_attempt = get_current_exam_attempt(request.user.id, exam.id)
+
         if exam_attempt is not None:
             exam_attempt = check_if_exam_timed_out(exam_attempt)
 

edx_exams/apps/core/api.py

@@ -18,7 +18,7 @@
     ExamDoesNotExist,
     ExamIllegalStatusTransition
 )
-from edx_exams.apps.core.models import CourseExamConfiguration, Exam, ExamAttempt, ProctoringProvider
+from edx_exams.apps.core.models import CourseExamConfiguration, Exam, ExamAttempt, ProctoringProvider, StudentAllowance
 from edx_exams.apps.core.signals.signals import (
     emit_exam_attempt_errored_event,
     emit_exam_attempt_rejected_event,
@@ -100,7 +100,7 @@ def update_attempt_status(attempt_id, to_status):
             raise ExamIllegalStatusTransition(error_msg)
 
         attempt_obj.start_time = datetime.now(pytz.UTC)
-        attempt_obj.allowed_time_limit_mins = _calculate_allowed_mins(attempt_obj.exam)
+        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)
@@ -210,15 +210,19 @@ def _check_exam_is_allowed_to_start(attempt_obj, user_id):
     return True, ''
 
 
-def _calculate_allowed_mins(exam):
+def _calculate_allowed_mins(user, exam):
     """
     Calculate the allowed minutes for an attempt, taking due date into account
     If an exam's duration + start time exceeds the due date, return the remaining time between
     due date and the current time
     """
     due_datetime = exam.due_date
+    allowance = StudentAllowance.get_allowance_for_user(user.id, exam.id)
     allowed_time_limit_mins = exam.time_limit_mins
 
+    if allowance:
+        allowed_time_limit_mins += allowance.extra_time_mins
+
     if due_datetime:
         current_datetime = datetime.now(pytz.UTC)
         if current_datetime + timedelta(minutes=allowed_time_limit_mins) > due_datetime:

edx_exams/apps/core/models.py

@@ -456,3 +456,14 @@ def get_allowances_for_course(cls, course_id):
         """
         filtered_query = Q(exam__course_id=course_id)
         return cls.objects.filter(filtered_query)
+
+    @classmethod
+    def get_allowance_for_user(cls, user_id, exam_id):
+        """
+        Returns the allowance for a user in an exam.
+        """
+        try:
+            allowance = cls.objects.get(user_id=user_id, exam_id=exam_id)
+        except cls.DoesNotExist:
+            allowance = None
+        return allowance

edx_exams/apps/core/tests/test_api.py

@@ -43,6 +43,7 @@
     ExamAttemptFactory,
     ExamFactory,
     ProctoringProviderFactory,
+    StudentAllowanceFactory,
     UserFactory
 )
 
@@ -261,6 +262,22 @@ def test_start_attempt(self):
             self.assertEqual(updated_attempt.start_time, timezone.now())
             self.assertEqual(updated_attempt.allowed_time_limit_mins, self.exam.time_limit_mins)
 
+    def test_start_attempt_with_time_allowance(self):
+        """
+        Test starting an exam with a time allowance grants the correct amount of time
+        """
+        with freeze_time(timezone.now()):
+            StudentAllowanceFactory.create(
+                user=self.user,
+                exam=self.exam,
+                extra_time_mins=10
+            )
+            attempt_id = update_attempt_status(self.exam_attempt.id, ExamAttemptStatus.started)
+            updated_attempt = ExamAttempt.get_attempt_by_id(attempt_id)
+            self.assertEqual(updated_attempt.status, ExamAttemptStatus.started)
+            self.assertEqual(updated_attempt.start_time, timezone.now())
+            self.assertEqual(updated_attempt.allowed_time_limit_mins, self.exam.time_limit_mins + 10)
+
     @ddt.data(
         True,
         False

edx_exams/apps/core/tests/test_models.py

@@ -4,11 +4,13 @@
 from django_dynamic_fixture import G
 from social_django.models import UserSocialAuth
 
-from edx_exams.apps.core.models import CourseExamConfiguration, Exam, User
+from edx_exams.apps.core.models import CourseExamConfiguration, Exam, StudentAllowance, User
 from edx_exams.apps.core.test_utils.factories import (
     CourseExamConfigurationFactory,
     ExamFactory,
-    ProctoringProviderFactory
+    ProctoringProviderFactory,
+    StudentAllowanceFactory,
+    UserFactory
 )
 
 
@@ -133,3 +135,35 @@ def test_create_or_update_new_config(self):
         new_config = CourseExamConfiguration.objects.get(course_id=other_course_id)
         self.assertEqual(new_config.provider, self.config.provider)
         self.assertEqual(new_config.escalation_email, self.escalation_email)
+
+
+class StudentAllowanceTests(TestCase):
+    """
+    StudentAllowance model tests.
+    """
+
+    def setUp(self):
+        super().setUp()
+
+        self.course_id = 'course-v1:edX+Test+Test_Course'
+        self.exam = ExamFactory(course_id=self.course_id)
+
+    def test_get_allowance_for_user(self):
+        user = UserFactory()
+        user_2 = UserFactory()
+        allowance = StudentAllowanceFactory(user=user, exam=self.exam)
+
+        self.assertEqual(StudentAllowance.get_allowance_for_user(self.exam.id, user.id), allowance)
+        self.assertIsNone(StudentAllowance.get_allowance_for_user(self.exam.id, user_2.id))
+
+    def test_get_allowances_for_course(self):
+        user = UserFactory()
+        user_2 = UserFactory()
+        exam_other_course = ExamFactory(course_id='course-v1:edX+Test+Test_Course_Other')
+        allowance = StudentAllowanceFactory(user=user, exam=self.exam)
+        allowance_2 = StudentAllowanceFactory(user=user_2, exam=self.exam)
+        StudentAllowanceFactory(user=user, exam=exam_other_course)
+
+        self.assertEqual(
+            set(StudentAllowance.get_allowances_for_course(self.course_id)), set([allowance, allowance_2])
+        )