Add a type hint for `get_device_handler()` and fix incorrect types. (#14055)

This was the last untyped handler from the HomeServer object. Since
it was being treated as Any (and thus unchecked) it was being used
incorrectly in a few places.

1 files changed, 4 insertions, 1 deletions

diff --git a/tests/rest/admin/test_device.py b/tests/rest/admin/test_device.py

index d52aee8f92..03f2112b07 100644
--- a/tests/rest/admin/test_device.py
+++ b/tests/rest/admin/test_device.py
@@ -19,6 +19,7 @@ from twisted.test.proto_helpers import MemoryReactor
 
 import synapse.rest.admin
 from synapse.api.errors import Codes
+from synapse.handlers.device import DeviceHandler
 from synapse.rest.client import login
 from synapse.server import HomeServer
 from synapse.util import Clock
@@ -34,7 +35,9 @@ class DeviceRestTestCase(unittest.HomeserverTestCase):
     ]
 
     def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
-        self.handler = hs.get_device_handler()
+        handler = hs.get_device_handler()
+        assert isinstance(handler, DeviceHandler)
+        self.handler = handler
 
         self.admin_user = self.register_user("admin", "pass", admin=True)
         self.admin_user_tok = self.login("admin", "pass")