fix: wrap into try/except block getting icon for xblock (#2509)

* fix: wrap into try/except block getting icon for xblock

* fix: revision after review

cms/djangoapps/contentstore/xblock_storage_handlers/view_handlers.py

@@ -88,11 +88,6 @@
 
 CREATE_IF_NOT_FOUND = ["course_info"]
 
-# List of categories to check for presence in the children of the XBlock.
-# This list is used to determine if all of the specified categories are absent
-# in the categories of the children XBlock instances otherwise icon class variable will be set to `None`.
-CATEGORIES_WITH_ABSENT_ICON = ["split_test"]
-
 # Useful constants for defining predicates
 NEVER = lambda x: False
 ALWAYS = lambda x: True
@@ -1068,10 +1063,6 @@ def create_xblock_info(  # lint-amnesty, pylint: disable=too-many-statements
         )
     else:
         user_partitions = get_user_partition_info(xblock, course=course)
-        all_excluded_categories_absent = all(
-            category not in [child.category for child in xblock.get_children()]
-            for category in CATEGORIES_WITH_ABSENT_ICON
-        )
         xblock_info.update(
             {
                 "edited_on": get_default_time_display(xblock.subtree_edited_on)
@@ -1101,7 +1092,7 @@ def create_xblock_info(  # lint-amnesty, pylint: disable=too-many-statements
                 "show_correctness": xblock.show_correctness,
                 "hide_from_toc": xblock.hide_from_toc,
                 "enable_hide_from_toc_ui": settings.FEATURES.get("ENABLE_HIDE_FROM_TOC_UI", False),
-                "xblock_type": get_icon(xblock) if is_xblock_unit and all_excluded_categories_absent else None,
+                "xblock_type": get_icon(xblock),
             }
         )
 

xmodule/split_test_block.py

@@ -15,6 +15,7 @@
 from web_fragments.fragment import Fragment
 from webob import Response
 from xblock.core import XBlock
+from xblock.exceptions import NoSuchServiceError
 from xblock.fields import Integer, ReferenceValueDict, Scope, String
 from xmodule.mako_block import MakoTemplateBlockBase
 from xmodule.modulestore.inheritance import UserPartitionList
@@ -172,10 +173,20 @@ def child_block(self):
     def child(self):
         """
         Return the user bound child block for the partition or None.
+
+        Handles the AttributeError exception that may occur when attempting to retrieve
+        an icon for the split_test xblock within the CMS.
         """
-        if self.child_block is not None:
-            return self.runtime.get_block_for_descriptor(self.child_block)
-        else:
+        try:
+            if self.child_block is not None:
+                return self.runtime.get_block_for_descriptor(self.child_block)
+            else:
+                return None
+        except AttributeError:
+            log.warning(
+                "Error while getting block instance for descriptor with location: [%s]",
+                self.location
+            )
             return None
 
     def get_child_block_by_location(self, location):
@@ -212,13 +223,31 @@ def get_content_titles(self):
     def get_child_blocks(self):
         """
         For grading--return just the chosen child.
+
+        Handles the NoSuchServiceError and ValueError exception that may occur when attempting to retrieve
+        an icon for the split_test xblock within the CMS.
         """
-        group_id = self.get_group_id()
+        try:
+            group_id = self.get_group_id()
+        except NoSuchServiceError:
+            log.warning(
+                "Error while getting user service in runtime with location: [%s]",
+                self.location
+            )
+            return []
+        except ValueError:
+            log.warning(
+                "Error while getting group ID for partition with location: [%s]",
+                self.location
+            )
+            return []
+
         if group_id is None:
             return []
 
         # group_id_to_child comes from json, so it has to have string keys
         str_group_id = str(group_id)
+        child_block = None
         if str_group_id in self.group_id_to_child:
             child_location = self.group_id_to_child[str_group_id]
             child_block = self.get_child_block_by_location(child_location)