cachedList will return None values

Author: erikjohnston

synapse/push/bulk_push_rule_evaluator.py

@@ -293,7 +293,7 @@ def _condition_checker(
     return True
 
 
-MemberMap = Dict[str, EventIdMembership]
+MemberMap = Dict[str, Optional[EventIdMembership]]
 Rule = Dict[str, dict]
 RulesByUser = Dict[str, List[Rule]]
 StateGroup = Union[object, int]
@@ -521,7 +521,7 @@ async def _update_rules_with_member_event_ids(
         joined_user_ids = {
             entry.user_id
             for entry in members.values()
-            if entry.membership == Membership.JOIN
+            if entry and entry.membership == Membership.JOIN
         }
 
         logger.debug("Joined: %r", joined_user_ids)

synapse/storage/databases/main/roommember.py

@@ -1011,16 +1011,21 @@ async def get_rooms_user_has_been_in(self, user_id: str) -> Set[str]:
     @cached(max_entries=5000)
     async def _get_membership_from_event_id(
         self, member_event_id: str
-    ) -> EventIdMembership:
+    ) -> Optional[EventIdMembership]:
         raise NotImplementedError()
 
     @cachedList(
         cached_method_name="_get_membership_from_event_id", list_name="member_event_ids"
     )
     async def get_membership_from_event_ids(
         self, member_event_ids: Iterable[str]
-    ) -> Dict[str, EventIdMembership]:
-        """Get user_id and membership of a set of event IDs."""
+    ) -> Dict[str, Optional[EventIdMembership]]:
+        """Get user_id and membership of a set of event IDs.
+
+        Returns:
+            Mapping from event ID to `EventIdMembership` if the event is a
+            membership event, otherwise the value is None.
+        """
 
         rows = await self.db_pool.simple_select_many_batch(
             table="room_memberships",

synapse/storage/persist_events.py

@@ -1027,7 +1027,8 @@ async def _is_server_still_joined(
                 events_to_check
             )
             is_still_joined = any(
-                member.membership == Membership.JOIN for member in members.values()
+                member and member.membership == Membership.JOIN
+                for member in members.values()
             )
             if is_still_joined:
                 return True
@@ -1068,7 +1069,7 @@ async def _is_server_still_joined(
         potentially_left_users.update(
             member.user_id
             for member in members.values()
-            if member.membership == Membership.JOIN
+            if member and member.membership == Membership.JOIN
         )
 
         return False