Require type hints in the handlers module. (#10831)

Adds missing type hints to methods in the synapse.handlers
module and requires all methods to have type hints there.

This also removes the unused construct_auth_difference method
from the FederationHandler.

synapse/handlers/appservice.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, Collection, Dict, List, Optional, Union
+from typing import TYPE_CHECKING, Collection, Dict, Iterable, List, Optional, Union
 
 from prometheus_client import Counter
 
@@ -58,7 +58,7 @@ class ApplicationServicesHandler:
         self.current_max = 0
         self.is_processing = False
 
-    def notify_interested_services(self, max_token: RoomStreamToken):
+    def notify_interested_services(self, max_token: RoomStreamToken) -> None:
         """Notifies (pushes) all application services interested in this event.
 
         Pushing is done asynchronously, so this method won't block for any
@@ -82,7 +82,7 @@ class ApplicationServicesHandler:
         self._notify_interested_services(max_token)
 
     @wrap_as_background_process("notify_interested_services")
-    async def _notify_interested_services(self, max_token: RoomStreamToken):
+    async def _notify_interested_services(self, max_token: RoomStreamToken) -> None:
         with Measure(self.clock, "notify_interested_services"):
             self.is_processing = True
             try:
@@ -100,7 +100,7 @@ class ApplicationServicesHandler:
                     for event in events:
                         events_by_room.setdefault(event.room_id, []).append(event)
 
-                    async def handle_event(event):
+                    async def handle_event(event: EventBase) -> None:
                         # Gather interested services
                         services = await self._get_services_for_event(event)
                         if len(services) == 0:
@@ -116,9 +116,9 @@ class ApplicationServicesHandler:
 
                         if not self.started_scheduler:
 
-                            async def start_scheduler():
+                            async def start_scheduler() -> None:
                                 try:
-                                    return await self.scheduler.start()
+                                    await self.scheduler.start()
                                 except Exception:
                                     logger.error("Application Services Failure")
 
@@ -137,7 +137,7 @@ class ApplicationServicesHandler:
                             "appservice_sender"
                         ).observe((now - ts) / 1000)
 
-                    async def handle_room_events(events):
+                    async def handle_room_events(events: Iterable[EventBase]) -> None:
                         for event in events:
                             await handle_event(event)
 
@@ -184,7 +184,7 @@ class ApplicationServicesHandler:
         stream_key: str,
         new_token: Optional[int],
         users: Optional[Collection[Union[str, UserID]]] = None,
-    ):
+    ) -> None:
         """This is called by the notifier in the background
         when a ephemeral event handled by the homeserver.
 
@@ -226,7 +226,7 @@ class ApplicationServicesHandler:
         stream_key: str,
         new_token: Optional[int],
         users: Collection[Union[str, UserID]],
-    ):
+    ) -> None:
         logger.debug("Checking interested services for %s" % (stream_key))
         with Measure(self.clock, "notify_interested_services_ephemeral"):
             for service in services: