1 files changed, 14 insertions, 5 deletions
diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py
index 08c6eabc6d..c2bbbb574e 100644
--- a/synapse/storage/background_updates.py
+++ b/synapse/storage/background_updates.py
@@ -12,20 +12,24 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+from types import TracebackType
 from typing import (
     TYPE_CHECKING,
+    Any,
     AsyncContextManager,
     Awaitable,
     Callable,
     Dict,
     Iterable,
+    List,
     Optional,
+    Type,
 )
 
 import attr
 
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.storage.types import Connection
+from synapse.storage.types import Connection, Cursor
 from synapse.types import JsonDict
 from synapse.util import Clock, json_encoder
 
@@ -74,7 +78,12 @@ class _BackgroundUpdateContextManager:
 
         return self._update_duration_ms
 
-    async def __aexit__(self, *exc) -> None:
+    async def __aexit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc: Optional[BaseException],
+        tb: Optional[TracebackType],
+    ) -> None:
         pass
 
 
@@ -352,7 +361,7 @@ class BackgroundUpdater:
             True if we have finished running all the background updates, otherwise False
         """
 
-        def get_background_updates_txn(txn):
+        def get_background_updates_txn(txn: Cursor) -> List[Dict[str, Any]]:
             txn.execute(
                 """
                 SELECT update_name, depends_on FROM background_updates
@@ -469,7 +478,7 @@ class BackgroundUpdater:
         self,
         update_name: str,
         update_handler: Callable[[JsonDict, int], Awaitable[int]],
-    ):
+    ) -> None:
         """Register a handler for doing a background update.
 
         The handler should take two arguments:
@@ -603,7 +612,7 @@ class BackgroundUpdater:
         else:
             runner = create_index_sqlite
 
-        async def updater(progress, batch_size):
+        async def updater(progress: JsonDict, batch_size: int) -> int:
             if runner is not None:
                 logger.info("Adding index %s to %s", index_name, table)
                 await self.db_pool.runWithConnection(runner)