Revert "Unrevert "Fix Gating to use grades API, instead of its own calculations""

This reverts commit 7aacae9a4f.

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):