Additional type hints for REST servlets (part 2). (#10674)

Applies the changes from #10665 to additional modules.

synapse/rest/client/initial_sync.py

@@ -12,25 +12,33 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import TYPE_CHECKING, Dict, List, Tuple
 
+from synapse.http.server import HttpServer
 from synapse.http.servlet import RestServlet, parse_boolean
+from synapse.http.site import SynapseRequest
 from synapse.rest.client._base import client_patterns
 from synapse.streams.config import PaginationConfig
+from synapse.types import JsonDict
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
 
 
 # TODO: Needs unit testing
 class InitialSyncRestServlet(RestServlet):
     PATTERNS = client_patterns("/initialSync$", v1=True)
 
-    def __init__(self, hs):
+    def __init__(self, hs: "HomeServer"):
         super().__init__()
         self.initial_sync_handler = hs.get_initial_sync_handler()
         self.auth = hs.get_auth()
         self.store = hs.get_datastore()
 
-    async def on_GET(self, request):
+    async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
         requester = await self.auth.get_user_by_req(request)
-        as_client_event = b"raw" not in request.args
+        args: Dict[bytes, List[bytes]] = request.args  # type: ignore
+        as_client_event = b"raw" not in args
         pagination_config = await PaginationConfig.from_request(self.store, request)
         include_archived = parse_boolean(request, "archived", default=False)
         content = await self.initial_sync_handler.snapshot_all_rooms(
@@ -43,5 +51,5 @@ class InitialSyncRestServlet(RestServlet):
         return 200, content
 
 
-def register_servlets(hs, http_server):
+def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
     InitialSyncRestServlet(hs).register(http_server)