Bugbear: Add Mutable Parameter fixes (#9682)

Part of #9366

Adds in fixes for B006 and B008, both relating to mutable parameter lint errors.

Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>

5 files changed, 19 insertions, 8 deletions

diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 98dac19a95..ad17123915 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -320,8 +320,8 @@ class PersistEventsStore:
         txn: LoggingTransaction,
         events_and_contexts: List[Tuple[EventBase, EventContext]],
         backfilled: bool,
-        state_delta_for_room: Dict[str, DeltaState] = {},
-        new_forward_extremeties: Dict[str, List[str]] = {},
+        state_delta_for_room: Optional[Dict[str, DeltaState]] = None,
+        new_forward_extremeties: Optional[Dict[str, List[str]]] = None,
     ):
         """Insert some number of room events into the necessary database tables.
 
@@ -342,6 +342,9 @@ class PersistEventsStore:
                 extremities.
 
         """
+        state_delta_for_room = state_delta_for_room or {}
+        new_forward_extremeties = new_forward_extremeties or {}
+
         all_events_and_contexts = events_and_contexts
 
         min_stream_order = events_and_contexts[0][0].internal_metadata.stream_ordering
diff --git a/synapse/storage/databases/main/group_server.py b/synapse/storage/databases/main/group_server.py
index 8f462dfc31..bd7826f4e9 100644
--- a/synapse/storage/databases/main/group_server.py
+++ b/synapse/storage/databases/main/group_server.py
@@ -1171,7 +1171,7 @@ class GroupServerStore(GroupServerWorkerStore):
         user_id: str,
         membership: str,
         is_admin: bool = False,
-        content: JsonDict = {},
+        content: Optional[JsonDict] = None,
         local_attestation: Optional[dict] = None,
         remote_attestation: Optional[dict] = None,
         is_publicised: bool = False,
@@ -1192,6 +1192,8 @@ class GroupServerStore(GroupServerWorkerStore):
             is_publicised: Whether this should be publicised.
         """
 
+        content = content or {}
+
         def _register_user_group_membership_txn(txn, next_id):
             # TODO: Upsert?
             self.db_pool.simple_delete_txn(
diff --git a/synapse/storage/databases/main/state.py b/synapse/storage/databases/main/state.py
index a7f371732f..93431efe00 100644
--- a/synapse/storage/databases/main/state.py
+++ b/synapse/storage/databases/main/state.py
@@ -190,7 +190,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
 
     # FIXME: how should this be cached?
     async def get_filtered_current_state_ids(
-        self, room_id: str, state_filter: StateFilter = StateFilter.all()
+        self, room_id: str, state_filter: Optional[StateFilter] = None
     ) -> StateMap[str]:
         """Get the current state event of a given type for a room based on the
         current_state_events table.  This may not be as up-to-date as the result
@@ -205,7 +205,9 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
             Map from type/state_key to event ID.
         """
 
-        where_clause, where_args = state_filter.make_sql_filter_clause()
+        where_clause, where_args = (
+            state_filter or StateFilter.all()
+        ).make_sql_filter_clause()
 
         if not where_clause:
             # We delegate to the cached version
diff --git a/synapse/storage/databases/state/bg_updates.py b/synapse/storage/databases/state/bg_updates.py
index 1fd333b707..75c09b3687 100644
--- a/synapse/storage/databases/state/bg_updates.py
+++ b/synapse/storage/databases/state/bg_updates.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import logging
+from typing import Optional
 
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.database import DatabasePool
@@ -73,8 +74,10 @@ class StateGroupBackgroundUpdateStore(SQLBaseStore):
             return count
 
     def _get_state_groups_from_groups_txn(
-        self, txn, groups, state_filter=StateFilter.all()
+        self, txn, groups, state_filter: Optional[StateFilter] = None
     ):
+        state_filter = state_filter or StateFilter.all()
+
         results = {group: {} for group in groups}
 
         where_clause, where_args = state_filter.make_sql_filter_clause()
diff --git a/synapse/storage/databases/state/store.py b/synapse/storage/databases/state/store.py
index 97ec65f757..dfcf89d91c 100644
--- a/synapse/storage/databases/state/store.py
+++ b/synapse/storage/databases/state/store.py
@@ -15,7 +15,7 @@
 
 import logging
 from collections import namedtuple
-from typing import Dict, Iterable, List, Set, Tuple
+from typing import Dict, Iterable, List, Optional, Set, Tuple
 
 from synapse.api.constants import EventTypes
 from synapse.storage._base import SQLBaseStore
@@ -210,7 +210,7 @@ class StateGroupDataStore(StateBackgroundUpdateStore, SQLBaseStore):
         return state_filter.filter_state(state_dict_ids), not missing_types
 
     async def _get_state_for_groups(
-        self, groups: Iterable[int], state_filter: StateFilter = StateFilter.all()
+        self, groups: Iterable[int], state_filter: Optional[StateFilter] = None
     ) -> Dict[int, MutableStateMap[str]]:
         """Gets the state at each of a list of state groups, optionally
         filtering by type/state_key
@@ -223,6 +223,7 @@ class StateGroupDataStore(StateBackgroundUpdateStore, SQLBaseStore):
         Returns:
             Dict of state group to state map.
         """
+        state_filter = state_filter or StateFilter.all()
 
         member_filter, non_member_filter = state_filter.get_member_split()