Make it possible to use dmypy (#9692)

Running `dmypy run` will do a `mypy` check while spinning up a daemon
that makes rerunning `dmypy run` a lot faster.

`dmypy` doesn't support `follow_imports = silent` and has
`local_partial_types` enabled, so this PR enables those options and
fixes the issues that were newly raised. Note that `local_partial_types`
will be enabled by default in upcoming mypy releases.

2 files changed, 6 insertions, 0 deletions

diff --git a/synapse/rest/admin/rooms.py b/synapse/rest/admin/rooms.py
index 263d8ec076..cfe1bebb91 100644
--- a/synapse/rest/admin/rooms.py
+++ b/synapse/rest/admin/rooms.py
@@ -390,6 +390,9 @@ class JoinRoomAliasServlet(ResolveRoomIdMixin, RestServlet):
     async def on_POST(
         self, request: SynapseRequest, room_identifier: str
     ) -> Tuple[int, JsonDict]:
+        # This will always be set by the time Twisted calls us.
+        assert request.args is not None
+
         requester = await self.auth.get_user_by_req(request)
         await assert_user_is_admin(self.auth, requester.user)
 
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index aaa56a7024..309bd2771b 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -833,6 +833,9 @@ class UserMediaRestServlet(RestServlet):
     async def on_GET(
         self, request: SynapseRequest, user_id: str
     ) -> Tuple[int, JsonDict]:
+        # This will always be set by the time Twisted calls us.
+        assert request.args is not None
+
         await assert_requester_is_admin(self.auth, request)
 
         if not self.is_mine(UserID.from_string(user_id)):