EDUCATOR-5240: LMS Returns 500 when requesting grade override history for a Subsection a Course Staff does not have access to (#24849)

* recreate issue

* add success and error_message

* catch case where target block has been hidden

lms/djangoapps/grades/rest_api/serializers.py

@@ -102,6 +102,8 @@ class SubsectionGradeResponseSerializer(serializers.Serializer):
     """
     Serializer for subsection grade response.
     """
+    success = serializers.BooleanField()
+    error_message = serializers.CharField(required=False)
     subsection_id = serializers.CharField()
     user_id = serializers.IntegerField()
     course_id = serializers.CharField()

lms/djangoapps/grades/rest_api/v1/gradebook_views.py

@@ -13,6 +13,7 @@ from django.contrib.auth import get_user_model
 from django.core.cache import cache
 from django.db.models import Case, Exists, F, OuterRef, When, Q
 from django.urls import reverse
+from django.utils.translation import ugettext_lazy as _
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey, UsageKey
 from rest_framework import status
@@ -920,6 +921,10 @@ class GradebookBulkUpdateView(GradeViewMixin, PaginatedAPIView):
         )
 
 
+class SubsectionUnavailableToUserException(Exception):
+    pass
+
+
 @view_auth_classes()
 class SubsectionGradeView(GradeViewMixin, APIView):
     """
@@ -1043,6 +1048,8 @@ class SubsectionGradeView(GradeViewMixin, APIView):
                 developer_message='Invalid UserID',
                 error_code='invalid_user_id'
             )
+        success = True
+        err_msg = ""
         override = None
         history = []
         history_record_limit = request.GET.get('history_record_limit')
@@ -1067,16 +1074,30 @@ class SubsectionGradeView(GradeViewMixin, APIView):
                 'possible_graded': original_grade.possible_graded,
             }
         except PersistentSubsectionGrade.DoesNotExist:
-            grade_data = self._get_grade_data_for_not_attempted_assignment(user_id, usage_key)
+            try:
+                grade_data = self._get_grade_data_for_not_attempted_assignment(user_id, usage_key)
+            except SubsectionUnavailableToUserException as exc:
+                success = False
+                err_msg = str(exc)
+                grade_data = {
+                    'earned_all': 0,
+                    'possible_all': 0,
+                    'earned_graded': 0,
+                    'possible_graded': 0,
+                }
 
-        results = SubsectionGradeResponseSerializer({
+        response_data = {
+            'success': success,
             'original_grade': grade_data,
             'override': override,
             'history': history,
             'subsection_id': usage_key,
             'user_id': user_id,
             'course_id': usage_key.course_key,
-        })
+        }
+        if not success:
+            response_data['error_message'] = err_msg
+        results = SubsectionGradeResponseSerializer(response_data)
         return Response(results.data)
 
     def _get_grade_data_for_not_attempted_assignment(self, user_id, usage_key):
@@ -1085,6 +1106,10 @@ class SubsectionGradeView(GradeViewMixin, APIView):
         """
         student = get_user_model().objects.get(id=user_id)
         course_structure = get_course_blocks(student, usage_key)
+        if usage_key not in course_structure:
+            raise SubsectionUnavailableToUserException(
+                _("Cannot override subsection grade: subsection is not available for target learner.")
+            )
         subsection_grade_factory = SubsectionGradeFactory(student, course_structure=course_structure)
         grade = subsection_grade_factory.create(course_structure[usage_key], read_only=True, force_calculate=True)
         grade_data = {

lms/djangoapps/grades/rest_api/v1/tests/test_gradebook_views.py

@@ -1706,6 +1706,7 @@ class SubsectionGradeViewTest(GradebookViewTestBase):
         )
 
         expected_data = {
+            'success': True,
             'original_grade': OrderedDict([
                 ('earned_all', 1.0),
                 ('possible_all', 2.0),
@@ -1733,6 +1734,7 @@ class SubsectionGradeViewTest(GradebookViewTestBase):
         )
 
         expected_data = {
+            'success': True,
             'original_grade': OrderedDict([
                 ('earned_all', 6.0),
                 ('possible_all', 12.0),
@@ -1770,6 +1772,7 @@ class SubsectionGradeViewTest(GradebookViewTestBase):
         )
 
         expected_data = {
+            'success': True,
             'original_grade': OrderedDict([
                 ('earned_all', 6.0),
                 ('possible_all', 12.0),
@@ -1827,6 +1830,7 @@ class SubsectionGradeViewTest(GradebookViewTestBase):
         )
 
         expected_data = {
+            'success': True,
             'original_grade': OrderedDict([
                 ('earned_all', 6.0),
                 ('possible_all', 12.0),
@@ -1928,6 +1932,7 @@ class SubsectionGradeViewTest(GradebookViewTestBase):
             self.get_url(subsection_id=self.usage_key, user_id=other_user.id)
         )
         expected_data = {
+            'success': True,
             'original_grade': OrderedDict([
                 ('earned_all', 0.0),
                 ('possible_all', 0.0),
@@ -1952,3 +1957,35 @@ class SubsectionGradeViewTest(GradebookViewTestBase):
         )
 
         self.assertEqual(status.HTTP_403_FORBIDDEN, resp.status_code)
+
+    @patch.dict('django.conf.settings.FEATURES', {'DISABLE_START_DATES': False})
+    def test_get_override_for_unreleased_block(self):
+        self.login_course_staff()
+        unreleased_subsection = ItemFactory.create(
+            parent_location=self.chapter_1.location,
+            category='sequential',
+            graded=True,
+            start=datetime(2999, 1, 1, tzinfo=UTC),  # arbitrary future date
+            display_name='Unreleased Section',
+        )
+
+        resp = self.client.get(
+            self.get_url(subsection_id=unreleased_subsection.location)
+        )
+
+        expected_data = {
+            'success': False,
+            'error_message': "Cannot override subsection grade: subsection is not available for target learner.",
+            'original_grade': OrderedDict([
+                ('earned_all', 0.0),
+                ('possible_all', 0.0),
+                ('earned_graded', 0.0),
+                ('possible_graded', 0.0)
+            ]),
+            'user_id': self.user_id,
+            'override': None,
+            'course_id': text_type(self.usage_key.course_key),
+            'subsection_id': text_type(unreleased_subsection.location),
+            'history': []
+        }
+        self.assertEqual(expected_data, resp.data)