Add type hints to the main state store.

changelog.d/12267.misc

@@ -0,0 +1 @@
+Add missing type hints for storage.

mypy.ini

@@ -43,7 +43,6 @@ exclude = (?x)
  |synapse/storage/databases/main/event_federation.py
  |synapse/storage/databases/main/push_rule.py
  |synapse/storage/databases/main/roommember.py
- |synapse/storage/databases/main/state.py
  |synapse/storage/schema/
 
  |tests/api/test_auth.py

synapse/storage/databases/main/state.py

@@ -12,9 +12,10 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import collections.abc
 import logging
-from typing import TYPE_CHECKING, Collection, Iterable, Optional, Set, Tuple
+from typing import TYPE_CHECKING, Dict, Iterable, Optional, Set, Tuple
+
+from frozendict import frozendict
 
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import NotFoundError, UnsupportedRoomVersionError
@@ -29,7 +30,7 @@
 from synapse.storage.databases.main.events_worker import EventsWorkerStore
 from synapse.storage.databases.main.roommember import RoomMemberWorkerStore
 from synapse.storage.state import StateFilter
-from synapse.types import JsonDict, StateMap
+from synapse.types import JsonDict, JsonMapping, StateMap
 from synapse.util.caches import intern_string
 from synapse.util.caches.descriptors import cached, cachedList
 
@@ -132,7 +133,7 @@ def get_room_version_id_txn(self, txn: LoggingTransaction, room_id: str) -> str:
 
  return room_version
 
- async def get_room_predecessor(self, room_id: str) -> Optional[dict]:
+ async def get_room_predecessor(self, room_id: str) -> Optional[JsonMapping]:
  """Get the predecessor of an upgraded room if it exists.
  Otherwise return None.
 
@@ -158,9 +159,10 @@ async def get_room_predecessor(self, room_id: str) -> Optional[dict]:
  predecessor = create_event.content.get("predecessor", None)
 
  # Ensure the key is a dictionary
- if not isinstance(predecessor, collections.abc.Mapping):
+ if not isinstance(predecessor, (dict, frozendict)):
  return None
 
+ # The keys must be strings since the data is JSON.
  return predecessor
 
  async def get_create_event_for_room(self, room_id: str) -> EventBase:
@@ -306,7 +308,9 @@ async def _get_state_group_for_event(self, event_id: str) -> Optional[int]:
  list_name="event_ids",
  num_args=1,
  )
- async def _get_state_group_for_events(self, event_ids: Collection[str]) -> JsonDict:
+ async def _get_state_group_for_events(
+ self, event_ids: Iterable[str]
+ ) -> Dict[str, int]:
  """Returns mapping event_id -> state_group"""
  rows = await self.db_pool.simple_select_many_batch(
  table="event_to_state_groups",
@@ -521,7 +525,7 @@ def _background_remove_left_rooms_txn(
  )
 
  for user_id in potentially_left_users - joined_users:
- await self.mark_remote_user_device_list_as_unsubscribed(user_id)
+ await self.mark_remote_user_device_list_as_unsubscribed(user_id) # type: ignore[attr-defined]
 
  return batch_size
 

synapse/util/caches/__init__.py

@@ -17,7 +17,7 @@
 import typing
 from enum import Enum, auto
 from sys import intern
-from typing import Any, Callable, Dict, List, Optional, Sized
+from typing import Any, Callable, Dict, List, Optional, Sized, TypeVar
 
 import attr
 from prometheus_client.core import Gauge
@@ -195,8 +195,10 @@ def register_cache(
  )
 }
 
+T = TypeVar("T", Optional[str], str)
 
-def intern_string(string: Optional[str]) -> Optional[str]:
+
+def intern_string(string: T) -> T:
  """Takes a (potentially) unicode string and interns it if it's ascii"""
  if string is None:
  return None