revert: show empty container blocks from the course blocks api when called by mobile (#27707)

REVE-52 is merged and mobile
traffic from older app versions is < 5% of the mobile traffic.
Therefore we dont need changes from this PR 325fbe4eb2 (diff-c061bf405edf96531766b26cc2bcc2bb3639d851e5d9f844612c2ea57c35e56e)

LEARNER-8377

lms/djangoapps/course_api/blocks/api.py

@@ -6,9 +6,7 @@ API function for retrieving course blocks data
 import lms.djangoapps.course_blocks.api as course_blocks_api
 from lms.djangoapps.course_blocks.transformers.access_denied_filter import AccessDeniedMessageFilterTransformer
 from lms.djangoapps.course_blocks.transformers.hidden_content import HiddenContentTransformer
-from lms.djangoapps.course_blocks.transformers.hide_empty import HideEmptyTransformer
 from openedx.core.djangoapps.content.block_structure.transformers import BlockStructureTransformers
-from openedx.core.lib.mobile_utils import is_request_from_mobile_app
 from openedx.features.effort_estimation.api import EffortEstimationTransformer
 
 from .serializers import BlockDictSerializer, BlockSerializer
@@ -98,10 +96,6 @@ def get_blocks(
     if hide_access_denials:
         transformers += [AccessDeniedMessageFilterTransformer()]
 
-    # TODO: Remove this after REVE-52 lands and old-mobile-app traffic falls to < 5% of mobile traffic
-    if is_request_from_mobile_app(request):
-        transformers += [HideEmptyTransformer()]
-
     if include_effort_estimation:
         transformers += [EffortEstimationTransformer()]
 

lms/djangoapps/course_api/blocks/tests/test_api.py

@@ -108,11 +108,10 @@ class TestGetBlocks(SharedModuleStoreTestCase):
             assert block['type'] == 'problem'
 
 
-# TODO: Remove this class after REVE-52 lands and old-mobile-app traffic falls to < 5% of mobile traffic
-@ddt.ddt
-class TestGetBlocksMobileHack(SharedModuleStoreTestCase):
+class TestGetBlocksVideoUrls(SharedModuleStoreTestCase):
     """
-    Tests that requests from the mobile app don't receive empty containers.
+    Tests the video blocks returned have their URL re-written for
+    encoded videos.
     """
 
     @classmethod
@@ -143,19 +142,6 @@ class TestGetBlocksMobileHack(SharedModuleStoreTestCase):
         self.request = RequestFactory().get("/dummy")
         self.request.user = self.user
 
-    @ddt.data(
-        *product([True, False], ['chapter', 'sequential', 'vertical'])
-    )
-    @ddt.unpack
-    def test_empty_containers(self, is_mobile, container_type):
-        with patch('lms.djangoapps.course_api.blocks.api.is_request_from_mobile_app', return_value=is_mobile):
-            blocks = get_blocks(self.request, self.course.location)
-        full_container_key = self.course.id.make_usage_key(container_type, f'full_{container_type}')
-        assert str(full_container_key) in blocks['blocks']
-        empty_container_key = self.course.id.make_usage_key(container_type, f'empty_{container_type}')
-        assert_containment = self.assertNotIn if is_mobile else self.assertIn
-        assert_containment(str(empty_container_key), blocks['blocks'])
-
     @patch('xmodule.video_module.VideoBlock.student_view_data')
     def test_video_urls_rewrite(self, video_data_patch):
         """

lms/djangoapps/course_blocks/transformers/hide_empty.py

@@ -1,43 +0,0 @@
-"""
-Hide Empty Transformer implementation.
-"""
-# TODO: Remove this file after REVE-52 lands and old-mobile-app traffic falls to < 5% of mobile traffic
-
-
-from openedx.core.djangoapps.content.block_structure.transformer import BlockStructureTransformer
-
-
-class HideEmptyTransformer(BlockStructureTransformer):
-    """
-    A transformer that removes any block from the course that could have
-    children but doesn't.
-    """
-    WRITE_VERSION = 1
-    READ_VERSION = 1
-
-    @classmethod
-    def name(cls):
-        """
-        Unique identifier for the transformer's class;
-        same identifier used in setup.py.
-        """
-        return "hide_empty"
-
-    @classmethod
-    def collect(cls, block_structure):
-        """
-        Collects any information that's necessary to execute this
-        transformer's transform method.
-        """
-        block_structure.request_xblock_fields('children', 'has_children')
-
-    def transform(self, usage_info, block_structure):
-        def _filter(block_key):
-            has_children = block_structure.get_xblock_field(block_key, 'has_children')
-            children = block_structure.get_xblock_field(block_key, 'children')
-            return has_children and not any(child in block_structure for child in children)
-
-        for _ in block_structure.post_order_traversal(
-            filter_func=block_structure.create_removal_filter(_filter)
-        ):
-            pass

setup.py

@@ -59,7 +59,6 @@ setup(
             "start_date = lms.djangoapps.course_blocks.transformers.start_date:StartDateTransformer",
             "user_partitions = lms.djangoapps.course_blocks.transformers.user_partitions:UserPartitionTransformer",
             "visibility = lms.djangoapps.course_blocks.transformers.visibility:VisibilityTransformer",
-            "hide_empty = lms.djangoapps.course_blocks.transformers.hide_empty:HideEmptyTransformer",
             "hidden_content = lms.djangoapps.course_blocks.transformers.hidden_content:HiddenContentTransformer",
             "course_blocks_api = lms.djangoapps.course_api.blocks.transformers.blocks_api:BlocksAPITransformer",
             "milestones = lms.djangoapps.course_api.blocks.transformers.milestones:MilestonesAndSpecialExamsTransformer",  # lint-amnesty, pylint: disable=line-too-long