From caeac6921a4f5c6ff2eaa4cb07278e5cbba45f63 Mon Sep 17 00:00:00 2001
From: Eric Fischer <efischer@edx.org>
Date: Tue, 1 Nov 2016 12:43:50 -0400
Subject: [PATCH 1/2] Fast-fail grades tasks if feature flag disabled

---
 lms/djangoapps/grades/tasks.py            | 3 +++
 lms/djangoapps/grades/tests/test_tasks.py | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/lms/djangoapps/grades/tasks.py b/lms/djangoapps/grades/tasks.py
index f65815389f..66a223a97b 100644
--- a/lms/djangoapps/grades/tasks.py
+++ b/lms/djangoapps/grades/tasks.py
@@ -13,6 +13,7 @@ from opaque_keys.edx.locator import CourseLocator
 from openedx.core.djangoapps.content.block_structure.api import get_course_in_cache
 from xmodule.modulestore.django import modulestore
 
+from .config.models import PersistentGradesEnabledFlag
 from .new.course_grade import CourseGradeFactory
 from .new.subsection_grade import SubsectionGradeFactory
 from .signals.signals import SUBSECTION_SCORE_CHANGED
@@ -76,6 +77,8 @@ def recalculate_course_grade(user_id, course_id):
        - user_id: serialized id of applicable User object
        - course_id: Unicode string representing the course
     """
+    if not PersistentGradesEnabledFlag.feature_enabled(course_id):
+        return
     student = User.objects.get(id=user_id)
     course_key = CourseLocator.from_string(course_id)
     course = modulestore().get_course(course_key, depth=0)
diff --git a/lms/djangoapps/grades/tests/test_tasks.py b/lms/djangoapps/grades/tests/test_tasks.py
index 959d1c1ff5..74d0a34097 100644
--- a/lms/djangoapps/grades/tests/test_tasks.py
+++ b/lms/djangoapps/grades/tests/test_tasks.py
@@ -179,7 +179,7 @@ class RecalculateSubsectionGradeTest(ModuleStoreTestCase):
             self.set_up_course(enable_subsection_grades=False)
             self.assertFalse(PersistentGradesEnabledFlag.feature_enabled(self.course.id))
             additional_queries = 1 if default_store == ModuleStoreEnum.Type.mongo else 0
-            with check_mongo_calls(2) and self.assertNumQueries(16 + additional_queries):
+            with check_mongo_calls(2) and self.assertNumQueries(5):
                 recalculate_subsection_grade.apply(args=tuple(self.score_changed_kwargs.values()))
 
     @skip("Pending completion of TNL-5089")

From a54c4ea4f915541ab772df9ccfb4aec8764ffb2e Mon Sep 17 00:00:00 2001
From: Eric Fischer <efischer@edx.org>
Date: Tue, 1 Nov 2016 14:31:52 -0400
Subject: [PATCH 2/2] Revert "Unrevert "Fix Gating to use grades API, instead
 of its own calculations""

This reverts commit 7aacae9a4f181ae81c987251e26383a2ab3d20eb.
---
 .../transformers/tests/test_milestones.py     |  25 +-
 lms/djangoapps/gating/api.py                  |  78 ++++--
 lms/djangoapps/gating/signals.py              |  25 +-
 lms/djangoapps/gating/tests/test_api.py       | 260 +++++++-----------
 lms/djangoapps/gating/tests/test_signals.py   |  26 +-
 lms/djangoapps/grades/module_grades.py        |  96 +++++++
 lms/djangoapps/grades/new/subsection_grade.py |  11 +-
 lms/djangoapps/grades/tasks.py                |   1 +
 lms/djangoapps/grades/tests/test_grades.py    | 192 +++++++++++++
 lms/djangoapps/grades/tests/test_tasks.py     |   3 +-
 10 files changed, 475 insertions(+), 242 deletions(-)
 create mode 100644 lms/djangoapps/grades/module_grades.py

diff --git a/lms/djangoapps/course_api/blocks/transformers/tests/test_milestones.py b/lms/djangoapps/course_api/blocks/transformers/tests/test_milestones.py
index f112789999..98b98119e9 100644
--- a/lms/djangoapps/course_api/blocks/transformers/tests/test_milestones.py
+++ b/lms/djangoapps/course_api/blocks/transformers/tests/test_milestones.py
@@ -1,7 +1,7 @@
 """
 Tests for ProctoredExamTransformer.
 """
-from mock import patch
+from mock import patch, Mock
 from nose.plugins.attrib import attr
 
 import ddt
@@ -133,16 +133,18 @@ class MilestonesTransformerTestCase(CourseStructureTestCase, MilestonesTestCaseM
         (
             'H',
             'A',
+            'B',
             ('course', 'A', 'B', 'C',)
         ),
         (
             'H',
             'ProctoredExam',
+            'D',
             ('course', 'A', 'B', 'C'),
         ),
     )
     @ddt.unpack
-    def test_gated(self, gated_block_ref, gating_block_ref, expected_blocks_before_completion):
+    def test_gated(self, gated_block_ref, gating_block_ref, gating_block_child, expected_blocks_before_completion):
         """
         First, checks that a student cannot see the gated block when it is gated by the gating block and no
         attempt has been made to complete the gating block.
@@ -162,14 +164,17 @@ class MilestonesTransformerTestCase(CourseStructureTestCase, MilestonesTestCaseM
         # clear the request cache to simulate a new request
         self.clear_caches()
 
-        # this call triggers reevaluation of prerequisites fulfilled by the gating block
-        lms_gating_api.evaluate_prerequisite(
-            self.course,
-            self.user,
-            self.blocks[gating_block_ref].location,
-            100.0,
-        )
-        with self.assertNumQueries(3):
+        # mock the api that the lms gating api calls to get the score for each block to always return 1 (ie 100%)
+        with patch('gating.api.get_module_score', Mock(return_value=1)):
+
+            # this call triggers reevaluation of prerequisites fulfilled by the parent of the
+            # block passed in, so we pass in a child of the gating block
+            lms_gating_api.evaluate_prerequisite(
+                self.course,
+                self.blocks[gating_block_child],
+                self.user.id,
+            )
+        with self.assertNumQueries(2):
             self.get_blocks_and_check_against_expected(self.user, self.ALL_BLOCKS_EXCEPT_SPECIAL)
 
     def test_staff_access(self):
diff --git a/lms/djangoapps/gating/api.py b/lms/djangoapps/gating/api.py
index d3d31155b9..0f2a8ea55b 100644
--- a/lms/djangoapps/gating/api.py
+++ b/lms/djangoapps/gating/api.py
@@ -10,14 +10,34 @@ import logging
 from openedx.core.lib.gating import api as gating_api
 from opaque_keys.edx.keys import UsageKey
 from lms.djangoapps.courseware.entrance_exams import get_entrance_exam_score
+from lms.djangoapps.grades.module_grades import get_module_score
 from util import milestones_helpers
 
 
 log = logging.getLogger(__name__)
 
 
+def _get_xblock_parent(xblock, category=None):
+    """
+    Returns the parent of the given XBlock. If an optional category is supplied,
+    traverses the ancestors of the XBlock and returns the first with the
+    given category.
+
+    Arguments:
+        xblock (XBlock): Get the parent of this XBlock
+        category (str): Find an ancestor with this category (e.g. sequential)
+    """
+    parent = xblock.get_parent()
+    if parent and category:
+        if parent.category == category:
+            return parent
+        else:
+            return _get_xblock_parent(parent, category)
+    return parent
+
+
 @gating_api.gating_enabled(default=False)
-def evaluate_prerequisite(course, user, subsection_usage_key, new_score):
+def evaluate_prerequisite(course, block, user_id):
     """
     Finds the parent subsection of the content in the course and evaluates
     any milestone relationships attached to that subsection. If the calculated
@@ -32,33 +52,39 @@ def evaluate_prerequisite(course, user, subsection_usage_key, new_score):
     Returns:
         None
     """
-    prereq_milestone = gating_api.get_gating_milestone(
-        course.id,
-        subsection_usage_key,
-        'fulfills'
-    )
-    if prereq_milestone:
-        gated_content_milestones = defaultdict(list)
-        for milestone in gating_api.find_gating_milestones(course.id, None, 'requires'):
-            gated_content_milestones[milestone['id']].append(milestone)
+    sequential = _get_xblock_parent(block, 'sequential')
+    if sequential:
+        prereq_milestone = gating_api.get_gating_milestone(
+            course.id,
+            sequential.location.for_branch(None),
+            'fulfills'
+        )
+        if prereq_milestone:
+            gated_content_milestones = defaultdict(list)
+            for milestone in gating_api.find_gating_milestones(course.id, None, 'requires'):
+                gated_content_milestones[milestone['id']].append(milestone)
 
-        gated_content = gated_content_milestones.get(prereq_milestone['id'])
-        if gated_content:
-            for milestone in gated_content:
-                # Default minimum score to 100
-                min_score = 100
-                requirements = milestone.get('requirements')
-                if requirements:
-                    try:
-                        min_score = int(requirements.get('min_score'))
-                    except (ValueError, TypeError):
-                        # Use default value of 100
-                        pass
+            gated_content = gated_content_milestones.get(prereq_milestone['id'])
+            if gated_content:
+                user = User.objects.get(id=user_id)
+                score = get_module_score(user, course, sequential) * 100
+                for milestone in gated_content:
+                    # Default minimum score to 100
+                    min_score = 100
+                    requirements = milestone.get('requirements')
+                    if requirements:
+                        try:
+                            min_score = int(requirements.get('min_score'))
+                        except (ValueError, TypeError):
+                            log.warning(
+                                'Failed to find minimum score for gating milestone %s, defaulting to 100',
+                                json.dumps(milestone)
+                            )
 
-                if new_score >= min_score:
-                    milestones_helpers.add_user_milestone({'id': user.id}, prereq_milestone)
-                else:
-                    milestones_helpers.remove_user_milestone({'id': user.id}, prereq_milestone)
+                    if score >= min_score:
+                        milestones_helpers.add_user_milestone({'id': user_id}, prereq_milestone)
+                    else:
+                        milestones_helpers.remove_user_milestone({'id': user_id}, prereq_milestone)
 
 
 def evaluate_entrance_exam(course, block, user_id):
diff --git a/lms/djangoapps/gating/signals.py b/lms/djangoapps/gating/signals.py
index 554ab642ab..368092dd4a 100644
--- a/lms/djangoapps/gating/signals.py
+++ b/lms/djangoapps/gating/signals.py
@@ -4,7 +4,7 @@ Signal handlers for the gating djangoapp
 from django.dispatch import receiver
 
 from gating import api as gating_api
-from lms.djangoapps.grades.signals.signals import PROBLEM_SCORE_CHANGED, SUBSECTION_SCORE_CHANGED
+from lms.djangoapps.grades.signals.signals import PROBLEM_SCORE_CHANGED
 from opaque_keys.edx.keys import CourseKey, UsageKey
 from xmodule.modulestore.django import modulestore
 
@@ -24,26 +24,5 @@ def handle_score_changed(**kwargs):
     """
     course = modulestore().get_course(CourseKey.from_string(kwargs.get('course_id')))
     block = modulestore().get_item(UsageKey.from_string(kwargs.get('usage_id')))
+    gating_api.evaluate_prerequisite(course, block, kwargs.get('user_id'))
     gating_api.evaluate_entrance_exam(course, block, kwargs.get('user_id'))
-
-
-@receiver(SUBSECTION_SCORE_CHANGED)
-def handle_subsection_score_changed(**kwargs):
-    """
-    Receives the SUBSECTION_SCORE_CHANGED signal and triggers the evaluation of
-    any milestone relationships which are attached to the updated content.
-    Arguments:
-        kwargs (dict): Contains user ID, course key, and content usage key
-    Returns:
-        None
-    """
-    course = kwargs['course']
-    if course.enable_subsection_gating:
-        subsection_grade = kwargs['subsection_grade']
-        new_score = subsection_grade.graded_total.earned / subsection_grade.graded_total.possible * 100.0
-        gating_api.evaluate_prerequisite(
-            course,
-            kwargs['user'],
-            subsection_grade.location,
-            new_score,
-        )
diff --git a/lms/djangoapps/gating/tests/test_api.py b/lms/djangoapps/gating/tests/test_api.py
index 4fca946872..3b1df7ce87 100644
--- a/lms/djangoapps/gating/tests/test_api.py
+++ b/lms/djangoapps/gating/tests/test_api.py
@@ -6,18 +6,15 @@ from nose.plugins.attrib import attr
 from ddt import ddt, data, unpack
 from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
+from courseware.tests.helpers import LoginEnrollmentTestCase
 
-from lms.djangoapps.courseware.access import has_access
-from lms.djangoapps.courseware.tests.helpers import get_request_for_user
-from lms.djangoapps.grades.tests.utils import answer_problem
-from lms.djangoapps.grades.new.course_grade import CourseGradeFactory
 from milestones import api as milestones_api
 from milestones.tests.utils import MilestonesTestCaseMixin
 from openedx.core.lib.gating import api as gating_api
-from request_cache.middleware import RequestCache
+from gating.api import _get_xblock_parent, evaluate_prerequisite
 
 
-class GatingTestCase(ModuleStoreTestCase):
+class GatingTestCase(LoginEnrollmentTestCase, ModuleStoreTestCase):
     """
     Base TestCase class for setting up a basic course structure
     and testing the gating feature
@@ -37,16 +34,6 @@ class GatingTestCase(ModuleStoreTestCase):
             display_name='edX 101'
         )
         self.course.enable_subsection_gating = True
-        grading_policy = {
-            "GRADER": [{
-                "type": "Homework",
-                "min_count": 3,
-                "drop_count": 0,
-                "short_label": "HW",
-                "weight": 1.0
-            }]
-        }
-        self.course.grading_policy = grading_policy
         self.course.save()
         self.store.update_item(self.course, 0)
 
@@ -54,195 +41,136 @@ class GatingTestCase(ModuleStoreTestCase):
         self.chapter1 = ItemFactory.create(
             parent_location=self.course.location,
             category='chapter',
-            display_name='chapter 1'
+            display_name='untitled chapter 1'
         )
 
         # create sequentials
         self.seq1 = ItemFactory.create(
             parent_location=self.chapter1.location,
             category='sequential',
-            display_name='gating sequential 1',
-            graded=True,
-            format='Homework',
+            display_name='untitled sequential 1'
         )
         self.seq2 = ItemFactory.create(
             parent_location=self.chapter1.location,
             category='sequential',
-            display_name='gated sequential 2',
-            graded=True,
-            format='Homework',
+            display_name='untitled sequential 2'
         )
-        self.seq3 = ItemFactory.create(
-            parent_location=self.chapter1.location,
-            category='sequential',
-            display_name='sequential 3',
-            graded=True,
-            format='Homework',
+
+        # create vertical
+        self.vert1 = ItemFactory.create(
+            parent_location=self.seq1.location,
+            category='vertical',
+            display_name='untitled vertical 1'
         )
 
         # create problem
-        self.gating_prob1 = ItemFactory.create(
-            parent_location=self.seq1.location,
+        self.prob1 = ItemFactory.create(
+            parent_location=self.vert1.location,
             category='problem',
-            display_name='gating problem 1',
-        )
-        self.gated_prob2 = ItemFactory.create(
-            parent_location=self.seq2.location,
-            category='problem',
-            display_name='gated problem 2',
-        )
-        self.prob3 = ItemFactory.create(
-            parent_location=self.seq3.location,
-            category='problem',
-            display_name='problem 3',
+            display_name='untitled problem 1'
         )
 
         # create orphan
-        self.orphan = ItemFactory.create(
+        self.prob2 = ItemFactory.create(
             parent_location=self.course.location,
             category='problem',
-            display_name='orphan'
-        )
-
-        self.prereq_milestone = None
-
-    def setup_gating_milestone(self, min_score):
-        """
-        Setup a gating milestone for testing.
-        Gating content: seq1 (must be fulfilled before access to seq2)
-        Gated content: seq2 (requires completion of seq1 before access)
-        """
-        gating_api.add_prerequisite(self.course.id, self.seq1.location)
-        gating_api.set_required_content(self.course.id, self.seq2.location, self.seq1.location, min_score)
-        self.prereq_milestone = gating_api.get_gating_milestone(self.course.id, self.seq1.location, 'fulfills')
-
-    def verify_access_to_gated_content(self, user, expected_access):
-        """
-        Verifies access to gated content for the given user is as expected.
-        """
-        # clear the request cache to flush any cached access results
-        RequestCache.clear_request_cache()
-
-        # access to gating content (seq1) remains constant
-        self.assertTrue(has_access(user, 'load', self.seq1, self.course.id))
-
-        # access to gated content (seq2) is as expected
-        self.assertEquals(bool(has_access(user, 'load', self.seq2, self.course.id)), expected_access)
-
-    def verify_user_has_prereq_milestone(self, user, expected_has_milestone):
-        """
-        Verifies whether or not the user has the prereq milestone
-        """
-        self.assertEquals(
-            milestones_api.user_has_milestone({'id': user.id}, self.prereq_milestone),
-            expected_has_milestone,
+            display_name='untitled problem 2'
         )
 
 
-@attr(shard=3)
-class TestGatedContent(GatingTestCase, MilestonesTestCaseMixin):
+class TestGetXBlockParent(GatingTestCase):
     """
-    Tests for gated content.
+    Tests for the get_xblock_parent function
     """
-    def setUp(self):
-        super(TestGatedContent, self).setUp()
-        self.setup_gating_milestone(100)
-        self.non_staff_user, _ = self.create_non_staff_user()
 
-    def test_gated_for_nonstaff(self):
-        self.verify_user_has_prereq_milestone(self.non_staff_user, expected_has_milestone=False)
-        self.verify_access_to_gated_content(self.non_staff_user, expected_access=False)
+    def test_get_direct_parent(self):
+        """ Test test_get_direct_parent """
 
-    def test_not_gated_for_staff(self):
-        self.verify_user_has_prereq_milestone(self.user, expected_has_milestone=False)
-        self.verify_access_to_gated_content(self.user, expected_access=True)
+        result = _get_xblock_parent(self.vert1)
+        self.assertEqual(result.location, self.seq1.location)
 
-    def _verify_course_grade(self, user, expected_percent):
-        """
-        Verifies the given user's course grade is the expected percentage.
-        Also verifies the user's grade information contains values for
-        all problems in the course, whether or not they are currently
-        gated.
-        """
-        course_grade = CourseGradeFactory(user).create(self.course)
-        for prob in [self.gating_prob1, self.gated_prob2, self.prob3]:
-            self.assertIn(prob.location, course_grade.locations_to_scores)
-        self.assertNotIn(self.orphan.location, course_grade.locations_to_scores)
+    def test_get_parent_with_category(self):
+        """ Test test_get_parent_of_category """
 
-        self.assertEquals(course_grade.percent, expected_percent)
+        result = _get_xblock_parent(self.vert1, 'sequential')
+        self.assertEqual(result.location, self.seq1.location)
+        result = _get_xblock_parent(self.vert1, 'chapter')
+        self.assertEqual(result.location, self.chapter1.location)
 
-    def test_gated_content_always_in_grades(self):
-        request = get_request_for_user(self.non_staff_user)
+    def test_get_parent_none(self):
+        """ Test test_get_parent_none """
 
-        # start with a grade from a non-gated subsection
-        answer_problem(self.course, request, self.prob3, 10, 10)
-
-        # verify gated status and overall course grade percentage
-        self.verify_user_has_prereq_milestone(self.non_staff_user, expected_has_milestone=False)
-        self.verify_access_to_gated_content(self.non_staff_user, expected_access=False)
-        self._verify_course_grade(self.non_staff_user, .33)
-
-        # fulfill the gated requirements
-        answer_problem(self.course, request, self.gating_prob1, 10, 10)
-
-        # verify gated status and overall course grade percentage
-        self.verify_user_has_prereq_milestone(self.non_staff_user, expected_has_milestone=True)
-        self.verify_access_to_gated_content(self.non_staff_user, expected_access=True)
-        self._verify_course_grade(self.non_staff_user, .67)
+        result = _get_xblock_parent(self.vert1, 'unit')
+        self.assertIsNone(result)
 
 
 @attr(shard=3)
 @ddt
-class TestHandleSubsectionGradeUpdates(GatingTestCase, MilestonesTestCaseMixin):
+class TestEvaluatePrerequisite(GatingTestCase, MilestonesTestCaseMixin):
     """
-    Tests for gated content when subsection grade is updated.
+    Tests for the evaluate_prerequisite function
     """
 
     def setUp(self):
-        super(TestHandleSubsectionGradeUpdates, self).setUp()
-        self.user, _ = self.create_non_staff_user()  # run tests for a non-staff user
-        self.request = get_request_for_user(self.user)
+        super(TestEvaluatePrerequisite, self).setUp()
+        self.user_dict = {'id': self.user.id}
+        self.prereq_milestone = None
 
-    def test_signal_handler_called(self):
-        with patch('lms.djangoapps.gating.signals.gating_api.evaluate_prerequisite') as mock_handler:
-            self.assertFalse(mock_handler.called)
-            answer_problem(self.course, self.request, self.gating_prob1, 1, 1)
-            self.assertTrue(mock_handler.called)
+    def _setup_gating_milestone(self, min_score):
+        """
+        Setup a gating milestone for testing
+        """
 
-    @data((1, 2, True), (1, 1, True), (0, 1, False))
-    @unpack
-    def test_min_score_achieved(self, earned, max_possible, result):
-        self.setup_gating_milestone(50)
-
-        self.verify_user_has_prereq_milestone(self.user, expected_has_milestone=False)
-        self.verify_access_to_gated_content(self.user, expected_access=False)
-
-        answer_problem(self.course, self.request, self.gating_prob1, earned, max_possible)
-
-        self.verify_user_has_prereq_milestone(self.user, expected_has_milestone=result)
-        self.verify_access_to_gated_content(self.user, expected_access=result)
-
-    @data((1, 2, False), (1, 1, True))
-    @unpack
-    def test_invalid_min_score(self, earned, max_possible, result):
-        self.setup_gating_milestone(None)
-
-        answer_problem(self.course, self.request, self.gating_prob1, earned, max_possible)
-        self.verify_user_has_prereq_milestone(self.user, expected_has_milestone=result)
-
-    def test_orphaned_xblock(self):
-        with patch('lms.djangoapps.gating.signals.gating_api.evaluate_prerequisite') as mock_handler:
-            self.assertFalse(mock_handler.called)
-            answer_problem(self.course, self.request, self.orphan, 1, 1)
-            self.assertFalse(mock_handler.called)
-
-    @patch('gating.api.milestones_helpers')
-    def test_no_prerequisites(self, mock_milestones):
-        answer_problem(self.course, self.request, self.gating_prob1, 1, 1)
-        self.assertFalse(mock_milestones.called)
-
-    @patch('gating.api.milestones_helpers')
-    def test_no_gated_content(self, mock_milestones):
         gating_api.add_prerequisite(self.course.id, self.seq1.location)
-        answer_problem(self.course, self.request, self.gating_prob1, 1, 1)
-        self.assertFalse(mock_milestones.called)
+        gating_api.set_required_content(self.course.id, self.seq2.location, self.seq1.location, min_score)
+        self.prereq_milestone = gating_api.get_gating_milestone(self.course.id, self.seq1.location, 'fulfills')
+
+    @patch('gating.api.get_module_score')
+    @data((.5, True), (1, True), (0, False))
+    @unpack
+    def test_min_score_achieved(self, module_score, result, mock_module_score):
+        """ Test test_min_score_achieved """
+
+        self._setup_gating_milestone(50)
+
+        mock_module_score.return_value = module_score
+        evaluate_prerequisite(self.course, self.prob1, self.user.id)
+        self.assertEqual(milestones_api.user_has_milestone(self.user_dict, self.prereq_milestone), result)
+
+    @patch('gating.api.log.warning')
+    @patch('gating.api.get_module_score')
+    @data((.5, False), (1, True))
+    @unpack
+    def test_invalid_min_score(self, module_score, result, mock_module_score, mock_log):
+        """ Test test_invalid_min_score """
+
+        self._setup_gating_milestone(None)
+
+        mock_module_score.return_value = module_score
+        evaluate_prerequisite(self.course, self.prob1, self.user.id)
+        self.assertEqual(milestones_api.user_has_milestone(self.user_dict, self.prereq_milestone), result)
+        self.assertTrue(mock_log.called)
+
+    @patch('gating.api.get_module_score')
+    def test_orphaned_xblock(self, mock_module_score):
+        """ Test test_orphaned_xblock """
+
+        evaluate_prerequisite(self.course, self.prob2, self.user.id)
+        self.assertFalse(mock_module_score.called)
+
+    @patch('gating.api.get_module_score')
+    def test_no_prerequisites(self, mock_module_score):
+        """ Test test_no_prerequisites """
+
+        evaluate_prerequisite(self.course, self.prob1, self.user.id)
+        self.assertFalse(mock_module_score.called)
+
+    @patch('gating.api.get_module_score')
+    def test_no_gated_content(self, mock_module_score):
+        """ Test test_no_gated_content """
+
+        # Setup gating milestones data
+        gating_api.add_prerequisite(self.course.id, self.seq1.location)
+
+        evaluate_prerequisite(self.course, self.prob1, self.user.id)
+        self.assertFalse(mock_module_score.called)
diff --git a/lms/djangoapps/gating/tests/test_signals.py b/lms/djangoapps/gating/tests/test_signals.py
index 319b6e8f2f..bb3eb41910 100644
--- a/lms/djangoapps/gating/tests/test_signals.py
+++ b/lms/djangoapps/gating/tests/test_signals.py
@@ -1,14 +1,14 @@
 """
 Unit tests for gating.signals module
 """
-from mock import patch, MagicMock
+from mock import patch
 
 from student.tests.factories import UserFactory
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
 from xmodule.modulestore.django import modulestore
 
-from gating.signals import handle_subsection_score_changed
+from gating.signals import handle_score_changed
 
 
 class TestHandleScoreChanged(ModuleStoreTestCase):
@@ -26,21 +26,25 @@ class TestHandleScoreChanged(ModuleStoreTestCase):
         """ Test evaluate_prerequisite is called when course.enable_subsection_gating is True """
         self.course.enable_subsection_gating = True
         modulestore().update_item(self.course, 0)
-        handle_subsection_score_changed(
+        handle_score_changed(
             sender=None,
-            course=self.course,
-            user=self.user,
-            subsection_grade=MagicMock(),
+            points_possible=1,
+            points_earned=1,
+            user_id=self.user.id,
+            course_id=unicode(self.course.id),
+            usage_id=unicode(self.test_usage_key)
         )
-        mock_evaluate.assert_called()
+        mock_evaluate.assert_called_with(self.course, self.course, self.user.id)  # pylint: disable=no-member
 
     @patch('gating.signals.gating_api.evaluate_prerequisite')
     def test_gating_disabled(self, mock_evaluate):
         """ Test evaluate_prerequisite is not called when course.enable_subsection_gating is False """
-        handle_subsection_score_changed(
+        handle_score_changed(
             sender=None,
-            course=self.course,
-            user=self.user,
-            subsection_grade=MagicMock(),
+            points_possible=1,
+            points_earned=1,
+            user_id=self.user.id,
+            course_id=unicode(self.course.id),
+            usage_id=unicode(self.test_usage_key)
         )
         mock_evaluate.assert_not_called()
diff --git a/lms/djangoapps/grades/module_grades.py b/lms/djangoapps/grades/module_grades.py
new file mode 100644
index 0000000000..a0e95a57e9
--- /dev/null
+++ b/lms/djangoapps/grades/module_grades.py
@@ -0,0 +1,96 @@
+"""
+Functionality for module-level grades.
+"""
+# TODO The score computation in this file is not accurate
+# since it is summing percentages instead of computing a
+# final percentage of the individual sums.
+# Regardless, this file and its code should be removed soon
+# as part of TNL-5062.
+
+from django.test.client import RequestFactory
+from courseware.model_data import FieldDataCache, ScoresClient
+from courseware.module_render import get_module_for_descriptor
+from opaque_keys.edx.locator import BlockUsageLocator
+from util.module_utils import yield_dynamic_descriptor_descendants
+
+
+def _get_mock_request(student):
+    """
+    Make a fake request because grading code expects to be able to look at
+    the request. We have to attach the correct user to the request before
+    grading that student.
+    """
+    request = RequestFactory().get('/')
+    request.user = student
+    return request
+
+
+def _calculate_score_for_modules(user_id, course, modules):
+    """
+    Calculates the cumulative score (percent) of the given modules
+    """
+
+    # removing branch and version from exam modules locator
+    # otherwise student module would not return scores since module usage keys would not match
+    modules = [m for m in modules]
+    locations = [
+        BlockUsageLocator(
+            course_key=course.id,
+            block_type=module.location.block_type,
+            block_id=module.location.block_id
+        )
+        if isinstance(module.location, BlockUsageLocator) and module.location.version
+        else module.location
+        for module in modules
+    ]
+
+    scores_client = ScoresClient(course.id, user_id)
+    scores_client.fetch_scores(locations)
+
+    # Iterate over all of the exam modules to get score percentage of user for each of them
+    module_percentages = []
+    ignore_categories = ['course', 'chapter', 'sequential', 'vertical', 'randomize', 'library_content']
+    for index, module in enumerate(modules):
+        if module.category not in ignore_categories and (module.graded or module.has_score):
+            module_score = scores_client.get(locations[index])
+            if module_score:
+                correct = module_score.correct or 0
+                total = module_score.total or 1
+                module_percentages.append(correct / total)
+
+    return sum(module_percentages) / float(len(module_percentages)) if module_percentages else 0
+
+
+def get_module_score(user, course, module):
+    """
+    Collects all children of the given module and calculates the cumulative
+    score for this set of modules for the given user.
+
+    Arguments:
+        user (User): The user
+        course (CourseModule): The course
+        module (XBlock): The module
+
+    Returns:
+        float: The cumulative score
+    """
+    def inner_get_module(descriptor):
+        """
+        Delegate to get_module_for_descriptor
+        """
+        field_data_cache = FieldDataCache([descriptor], course.id, user)
+        return get_module_for_descriptor(
+            user,
+            _get_mock_request(user),
+            descriptor,
+            field_data_cache,
+            course.id,
+            course=course
+        )
+
+    modules = yield_dynamic_descriptor_descendants(
+        module,
+        user.id,
+        inner_get_module
+    )
+    return _calculate_score_for_modules(user.id, course, modules)
diff --git a/lms/djangoapps/grades/new/subsection_grade.py b/lms/djangoapps/grades/new/subsection_grade.py
index 6a624e862d..33623009e0 100644
--- a/lms/djangoapps/grades/new/subsection_grade.py
+++ b/lms/djangoapps/grades/new/subsection_grade.py
@@ -253,6 +253,11 @@ class SubsectionGradeFactory(object):
         """
         Updates the SubsectionGrade object for the student and subsection.
         """
+        # Save ourselves the extra queries if the course does not persist
+        # subsection grades.
+        if not PersistentGradesEnabledFlag.feature_enabled(self.course.id):
+            return
+
         self._log_event(log.warning, u"update, subsection: {}".format(subsection.location))
 
         block_structure = self._get_block_structure(block_structure)
@@ -277,10 +282,8 @@ class SubsectionGradeFactory(object):
                 ):
                     return orig_subsection_grade
 
-        if PersistentGradesEnabledFlag.feature_enabled(self.course.id):
-            grade_model = calculated_grade.update_or_create_model(self.student)
-            self._update_saved_subsection_grade(subsection.location, grade_model)
-
+        grade_model = calculated_grade.update_or_create_model(self.student)
+        self._update_saved_subsection_grade(subsection.location, grade_model)
         return calculated_grade
 
     @lazy
diff --git a/lms/djangoapps/grades/tasks.py b/lms/djangoapps/grades/tasks.py
index 66a223a97b..ce0c7e6504 100644
--- a/lms/djangoapps/grades/tasks.py
+++ b/lms/djangoapps/grades/tasks.py
@@ -33,6 +33,7 @@ def recalculate_subsection_grade(user_id, course_id, usage_id, only_if_higher):
         value.
     """
     course_key = CourseLocator.from_string(course_id)
+
     student = User.objects.get(id=user_id)
     scored_block_usage_key = UsageKey.from_string(usage_id).replace(course_key=course_key)
 
diff --git a/lms/djangoapps/grades/tests/test_grades.py b/lms/djangoapps/grades/tests/test_grades.py
index a2f4dad369..655bd6f7ca 100644
--- a/lms/djangoapps/grades/tests/test_grades.py
+++ b/lms/djangoapps/grades/tests/test_grades.py
@@ -27,6 +27,7 @@ from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 from .utils import answer_problem
 from .. import course_grades
 from ..course_grades import summary as grades_summary
+from ..module_grades import get_module_score
 from ..new.course_grade import CourseGradeFactory
 from ..new.subsection_grade import SubsectionGradeFactory
 
@@ -341,3 +342,194 @@ class TestScoreForModule(SharedModuleStoreTestCase):
         earned, possible = self.course_grade.score_for_module(self.m.location)
         self.assertEqual(earned, 0)
         self.assertEqual(possible, 0)
+
+
+class TestGetModuleScore(LoginEnrollmentTestCase, SharedModuleStoreTestCase):
+    """
+    Test get_module_score
+    """
+    @classmethod
+    def setUpClass(cls):
+        super(TestGetModuleScore, cls).setUpClass()
+        cls.course = CourseFactory.create()
+        cls.chapter = ItemFactory.create(
+            parent=cls.course,
+            category="chapter",
+            display_name="Test Chapter"
+        )
+        cls.seq1 = ItemFactory.create(
+            parent=cls.chapter,
+            category='sequential',
+            display_name="Test Sequential 1",
+            graded=True
+        )
+        cls.seq2 = ItemFactory.create(
+            parent=cls.chapter,
+            category='sequential',
+            display_name="Test Sequential 2",
+            graded=True
+        )
+        cls.seq3 = ItemFactory.create(
+            parent=cls.chapter,
+            category='sequential',
+            display_name="Test Sequential 3",
+            graded=True
+        )
+        cls.vert1 = ItemFactory.create(
+            parent=cls.seq1,
+            category='vertical',
+            display_name='Test Vertical 1'
+        )
+        cls.vert2 = ItemFactory.create(
+            parent=cls.seq2,
+            category='vertical',
+            display_name='Test Vertical 2'
+        )
+        cls.vert3 = ItemFactory.create(
+            parent=cls.seq3,
+            category='vertical',
+            display_name='Test Vertical 3'
+        )
+        cls.randomize = ItemFactory.create(
+            parent=cls.vert2,
+            category='randomize',
+            display_name='Test Randomize'
+        )
+        cls.library_content = ItemFactory.create(
+            parent=cls.vert3,
+            category='library_content',
+            display_name='Test Library Content'
+        )
+        problem_xml = MultipleChoiceResponseXMLFactory().build_xml(
+            question_text='The correct answer is Choice 3',
+            choices=[False, False, True, False],
+            choice_names=['choice_0', 'choice_1', 'choice_2', 'choice_3']
+        )
+        cls.problem1 = ItemFactory.create(
+            parent=cls.vert1,
+            category="problem",
+            display_name="Test Problem 1",
+            data=problem_xml
+        )
+        cls.problem2 = ItemFactory.create(
+            parent=cls.vert1,
+            category="problem",
+            display_name="Test Problem 2",
+            data=problem_xml
+        )
+        cls.problem3 = ItemFactory.create(
+            parent=cls.randomize,
+            category="problem",
+            display_name="Test Problem 3",
+            data=problem_xml
+        )
+        cls.problem4 = ItemFactory.create(
+            parent=cls.randomize,
+            category="problem",
+            display_name="Test Problem 4",
+            data=problem_xml
+        )
+
+        cls.problem5 = ItemFactory.create(
+            parent=cls.library_content,
+            category="problem",
+            display_name="Test Problem 5",
+            data=problem_xml
+        )
+        cls.problem6 = ItemFactory.create(
+            parent=cls.library_content,
+            category="problem",
+            display_name="Test Problem 6",
+            data=problem_xml
+        )
+
+    def setUp(self):
+        """
+        Set up test course
+        """
+        super(TestGetModuleScore, self).setUp()
+
+        self.request = get_request_for_user(UserFactory())
+        self.client.login(username=self.request.user.username, password="test")
+        CourseEnrollment.enroll(self.request.user, self.course.id)
+
+        self.course_structure = get_course_blocks(self.request.user, self.course.location)
+
+        # warm up the score cache to allow accurate query counts, even if tests are run in random order
+        get_module_score(self.request.user, self.course, self.seq1)
+
+    def test_subsection_scores(self):
+        """
+        Test test_get_module_score
+        """
+        # One query is for getting the list of disabled XBlocks (which is
+        # then stored in the request).
+        with self.assertNumQueries(1):
+            score = get_module_score(self.request.user, self.course, self.seq1)
+        new_score = SubsectionGradeFactory(self.request.user, self.course, self.course_structure).create(self.seq1)
+        self.assertEqual(score, 0)
+        self.assertEqual(new_score.all_total.earned, 0)
+
+        answer_problem(self.course, self.request, self.problem1)
+        answer_problem(self.course, self.request, self.problem2)
+
+        with self.assertNumQueries(1):
+            score = get_module_score(self.request.user, self.course, self.seq1)
+        new_score = SubsectionGradeFactory(self.request.user, self.course, self.course_structure).create(self.seq1)
+        self.assertEqual(score, 1.0)
+        self.assertEqual(new_score.all_total.earned, 2.0)
+        # These differ because get_module_score normalizes the subsection score
+        # to 1, which can cause incorrect aggregation behavior that will be
+        # fixed by TNL-5062.
+
+        answer_problem(self.course, self.request, self.problem1)
+        answer_problem(self.course, self.request, self.problem2, 0)
+
+        with self.assertNumQueries(1):
+            score = get_module_score(self.request.user, self.course, self.seq1)
+        new_score = SubsectionGradeFactory(self.request.user, self.course, self.course_structure).create(self.seq1)
+        self.assertEqual(score, .5)
+        self.assertEqual(new_score.all_total.earned, 1.0)
+
+    def test_get_module_score_with_empty_score(self):
+        """
+        Test test_get_module_score_with_empty_score
+        """
+        set_score(self.request.user.id, self.problem1.location, None, None)  # pylint: disable=no-member
+        set_score(self.request.user.id, self.problem2.location, None, None)  # pylint: disable=no-member
+
+        with self.assertNumQueries(1):
+            score = get_module_score(self.request.user, self.course, self.seq1)
+        self.assertEqual(score, 0)
+
+        answer_problem(self.course, self.request, self.problem1)
+
+        with self.assertNumQueries(1):
+            score = get_module_score(self.request.user, self.course, self.seq1)
+        self.assertEqual(score, 0.5)
+
+        answer_problem(self.course, self.request, self.problem2)
+
+        with self.assertNumQueries(1):
+            score = get_module_score(self.request.user, self.course, self.seq1)
+        self.assertEqual(score, 1.0)
+
+    def test_get_module_score_with_randomize(self):
+        """
+        Test test_get_module_score_with_randomize
+        """
+        answer_problem(self.course, self.request, self.problem3)
+        answer_problem(self.course, self.request, self.problem4)
+
+        score = get_module_score(self.request.user, self.course, self.seq2)
+        self.assertEqual(score, 1.0)
+
+    def test_get_module_score_with_library_content(self):
+        """
+        Test test_get_module_score_with_library_content
+        """
+        answer_problem(self.course, self.request, self.problem5)
+        answer_problem(self.course, self.request, self.problem6)
+
+        score = get_module_score(self.request.user, self.course, self.seq3)
+        self.assertEqual(score, 1.0)
diff --git a/lms/djangoapps/grades/tests/test_tasks.py b/lms/djangoapps/grades/tests/test_tasks.py
index 74d0a34097..5379338846 100644
--- a/lms/djangoapps/grades/tests/test_tasks.py
+++ b/lms/djangoapps/grades/tests/test_tasks.py
@@ -178,8 +178,7 @@ class RecalculateSubsectionGradeTest(ModuleStoreTestCase):
         with self.store.default_store(default_store):
             self.set_up_course(enable_subsection_grades=False)
             self.assertFalse(PersistentGradesEnabledFlag.feature_enabled(self.course.id))
-            additional_queries = 1 if default_store == ModuleStoreEnum.Type.mongo else 0
-            with check_mongo_calls(2) and self.assertNumQueries(5):
+            with check_mongo_calls(2) and self.assertNumQueries(2):
                 recalculate_subsection_grade.apply(args=tuple(self.score_changed_kwargs.values()))
 
     @skip("Pending completion of TNL-5089")