Add missing type hints to tests.handlers. (#14680)

And do not allow untyped defs in tests.handlers.

19 files changed, 524 insertions, 373 deletions

diff --git a/tests/handlers/test_appservice.py b/tests/handlers/test_appservice.py
index 57bfbd7734..a7495ab21a 100644
--- a/tests/handlers/test_appservice.py
+++ b/tests/handlers/test_appservice.py
@@ -31,7 +31,7 @@ from synapse.appservice import (
 from synapse.handlers.appservice import ApplicationServicesHandler
 from synapse.rest.client import login, receipts, register, room, sendtodevice
 from synapse.server import HomeServer
-from synapse.types import RoomStreamToken
+from synapse.types import JsonDict, RoomStreamToken
 from synapse.util import Clock
 from synapse.util.stringutils import random_string
 
@@ -44,7 +44,7 @@ from tests.utils import MockClock
 class AppServiceHandlerTestCase(unittest.TestCase):
     """Tests the ApplicationServicesHandler."""
 
-    def setUp(self):
+    def setUp(self) -> None:
         self.mock_store = Mock()
         self.mock_as_api = Mock()
         self.mock_scheduler = Mock()
@@ -61,7 +61,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
         self.handler = ApplicationServicesHandler(hs)
         self.event_source = hs.get_event_sources()
 
-    def test_notify_interested_services(self):
+    def test_notify_interested_services(self) -> None:
         interested_service = self._mkservice(is_interested_in_event=True)
         services = [
             self._mkservice(is_interested_in_event=False),
@@ -90,7 +90,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
             interested_service, events=[event]
         )
 
-    def test_query_user_exists_unknown_user(self):
+    def test_query_user_exists_unknown_user(self) -> None:
         user_id = "@someone:anywhere"
         services = [self._mkservice(is_interested_in_event=True)]
         services[0].is_interested_in_user.return_value = True
@@ -107,7 +107,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
 
         self.mock_as_api.query_user.assert_called_once_with(services[0], user_id)
 
-    def test_query_user_exists_known_user(self):
+    def test_query_user_exists_known_user(self) -> None:
         user_id = "@someone:anywhere"
         services = [self._mkservice(is_interested_in_event=True)]
         services[0].is_interested_in_user.return_value = True
@@ -127,7 +127,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
             "query_user called when it shouldn't have been.",
         )
 
-    def test_query_room_alias_exists(self):
+    def test_query_room_alias_exists(self) -> None:
         room_alias_str = "#foo:bar"
         room_alias = Mock()
         room_alias.to_string.return_value = room_alias_str
@@ -157,7 +157,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
         self.assertEqual(result.room_id, room_id)
         self.assertEqual(result.servers, servers)
 
-    def test_get_3pe_protocols_no_appservices(self):
+    def test_get_3pe_protocols_no_appservices(self) -> None:
         self.mock_store.get_app_services.return_value = []
         response = self.successResultOf(
             defer.ensureDeferred(self.handler.get_3pe_protocols("my-protocol"))
@@ -165,7 +165,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
         self.mock_as_api.get_3pe_protocol.assert_not_called()
         self.assertEqual(response, {})
 
-    def test_get_3pe_protocols_no_protocols(self):
+    def test_get_3pe_protocols_no_protocols(self) -> None:
         service = self._mkservice(False, [])
         self.mock_store.get_app_services.return_value = [service]
         response = self.successResultOf(
@@ -174,7 +174,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
         self.mock_as_api.get_3pe_protocol.assert_not_called()
         self.assertEqual(response, {})
 
-    def test_get_3pe_protocols_protocol_no_response(self):
+    def test_get_3pe_protocols_protocol_no_response(self) -> None:
         service = self._mkservice(False, ["my-protocol"])
         self.mock_store.get_app_services.return_value = [service]
         self.mock_as_api.get_3pe_protocol.return_value = make_awaitable(None)
@@ -186,7 +186,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
         )
         self.assertEqual(response, {})
 
-    def test_get_3pe_protocols_select_one_protocol(self):
+    def test_get_3pe_protocols_select_one_protocol(self) -> None:
         service = self._mkservice(False, ["my-protocol"])
         self.mock_store.get_app_services.return_value = [service]
         self.mock_as_api.get_3pe_protocol.return_value = make_awaitable(
@@ -202,7 +202,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
             response, {"my-protocol": {"x-protocol-data": 42, "instances": []}}
         )
 
-    def test_get_3pe_protocols_one_protocol(self):
+    def test_get_3pe_protocols_one_protocol(self) -> None:
         service = self._mkservice(False, ["my-protocol"])
         self.mock_store.get_app_services.return_value = [service]
         self.mock_as_api.get_3pe_protocol.return_value = make_awaitable(
@@ -218,7 +218,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
             response, {"my-protocol": {"x-protocol-data": 42, "instances": []}}
         )
 
-    def test_get_3pe_protocols_multiple_protocol(self):
+    def test_get_3pe_protocols_multiple_protocol(self) -> None:
         service_one = self._mkservice(False, ["my-protocol"])
         service_two = self._mkservice(False, ["other-protocol"])
         self.mock_store.get_app_services.return_value = [service_one, service_two]
@@ -237,11 +237,13 @@ class AppServiceHandlerTestCase(unittest.TestCase):
             },
         )
 
-    def test_get_3pe_protocols_multiple_info(self):
+    def test_get_3pe_protocols_multiple_info(self) -> None:
         service_one = self._mkservice(False, ["my-protocol"])
         service_two = self._mkservice(False, ["my-protocol"])
 
-        async def get_3pe_protocol(service, unusedProtocol):
+        async def get_3pe_protocol(
+            service: ApplicationService, protocol: str
+        ) -> Optional[JsonDict]:
             if service == service_one:
                 return {
                     "x-protocol-data": 42,
@@ -276,7 +278,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
             },
         )
 
-    def test_notify_interested_services_ephemeral(self):
+    def test_notify_interested_services_ephemeral(self) -> None:
         """
         Test sending ephemeral events to the appservice handler are scheduled
         to be pushed out to interested appservices, and that the stream ID is
@@ -306,7 +308,7 @@ class AppServiceHandlerTestCase(unittest.TestCase):
             580,
         )
 
-    def test_notify_interested_services_ephemeral_out_of_order(self):
+    def test_notify_interested_services_ephemeral_out_of_order(self) -> None:
         """
         Test sending out of order ephemeral events to the appservice handler
         are ignored.
@@ -390,7 +392,7 @@ class ApplicationServicesHandlerSendEventsTestCase(unittest.HomeserverTestCase):
         receipts.register_servlets,
     ]
 
-    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.hs = hs
         # Mock the ApplicationServiceScheduler's _TransactionController's send method so that
         # we can track any outgoing ephemeral events
@@ -417,7 +419,7 @@ class ApplicationServicesHandlerSendEventsTestCase(unittest.HomeserverTestCase):
             "exclusive_as_user", "password", self.exclusive_as_user_device_id
         )
 
-    def _notify_interested_services(self):
+    def _notify_interested_services(self) -> None:
         # This is normally set in `notify_interested_services` but we need to call the
         # internal async version so the reactor gets pushed to completion.
         self.hs.get_application_service_handler().current_max += 1
@@ -443,7 +445,7 @@ class ApplicationServicesHandlerSendEventsTestCase(unittest.HomeserverTestCase):
     )
     def test_match_interesting_room_members(
         self, interesting_user: str, should_notify: bool
-    ):
+    ) -> None:
         """
         Test to make sure that a interesting user (local or remote) in the room is
         notified as expected when someone else in the room sends a message.
@@ -512,7 +514,9 @@ class ApplicationServicesHandlerSendEventsTestCase(unittest.HomeserverTestCase):
         else:
             self.send_mock.assert_not_called()
 
-    def test_application_services_receive_events_sent_by_interesting_local_user(self):
+    def test_application_services_receive_events_sent_by_interesting_local_user(
+        self,
+    ) -> None:
         """
         Test to make sure that a messages sent from a local user can be interesting and
         picked up by the appservice.
@@ -568,7 +572,7 @@ class ApplicationServicesHandlerSendEventsTestCase(unittest.HomeserverTestCase):
         self.assertEqual(events[0]["type"], "m.room.message")
         self.assertEqual(events[0]["sender"], alice)
 
-    def test_sending_read_receipt_batches_to_application_services(self):
+    def test_sending_read_receipt_batches_to_application_services(self) -> None:
         """Tests that a large batch of read receipts are sent correctly to
         interested application services.
         """
@@ -644,7 +648,7 @@ class ApplicationServicesHandlerSendEventsTestCase(unittest.HomeserverTestCase):
     @unittest.override_config(
         {"experimental_features": {"msc2409_to_device_messages_enabled": True}}
     )
-    def test_application_services_receive_local_to_device(self):
+    def test_application_services_receive_local_to_device(self) -> None:
         """
         Test that when a user sends a to-device message to another user
         that is an application service's user namespace, the
@@ -722,7 +726,7 @@ class ApplicationServicesHandlerSendEventsTestCase(unittest.HomeserverTestCase):
     @unittest.override_config(
         {"experimental_features": {"msc2409_to_device_messages_enabled": True}}
     )
-    def test_application_services_receive_bursts_of_to_device(self):
+    def test_application_services_receive_bursts_of_to_device(self) -> None:
         """
         Test that when a user sends >100 to-device messages at once, any
         interested AS's will receive them in separate transactions.
@@ -913,7 +917,7 @@ class ApplicationServicesHandlerDeviceListsTestCase(unittest.HomeserverTestCase)
         experimental_feature_enabled: bool,
         as_supports_txn_extensions: bool,
         as_should_receive_device_list_updates: bool,
-    ):
+    ) -> None:
         """
         Tests that an application service receives notice of changed device
         lists for a user, when a user changes their device lists.
@@ -1070,7 +1074,7 @@ class ApplicationServicesHandlerOtkCountsTestCase(unittest.HomeserverTestCase):
         and a room for the users to talk in.
         """
 
-        async def preparation():
+        async def preparation() -> None:
             await self._add_otks_for_device(self._sender_user, self._sender_device, 42)
             await self._add_fallback_key_for_device(
                 self._sender_user, self._sender_device, used=True
diff --git a/tests/handlers/test_cas.py b/tests/handlers/test_cas.py
index 2b21547d0f..2733719d82 100644
--- a/tests/handlers/test_cas.py
+++ b/tests/handlers/test_cas.py
@@ -199,7 +199,7 @@ class CasHandlerTestCase(HomeserverTestCase):
         )
 
 
-def _mock_request():
+def _mock_request() -> Mock:
     """Returns a mock which will stand in as a SynapseRequest"""
     mock = Mock(
         spec=[
diff --git a/tests/handlers/test_directory.py b/tests/handlers/test_directory.py
index 3b72c4c9d0..90aec484c4 100644
--- a/tests/handlers/test_directory.py
+++ b/tests/handlers/test_directory.py
@@ -20,6 +20,7 @@ from twisted.test.proto_helpers import MemoryReactor
 import synapse.api.errors
 import synapse.rest.admin
 from synapse.api.constants import EventTypes
+from synapse.events import EventBase
 from synapse.rest.client import directory, login, room
 from synapse.server import HomeServer
 from synapse.types import JsonDict, RoomAlias, create_requester
@@ -201,7 +202,7 @@ class TestDeleteAlias(unittest.HomeserverTestCase):
         self.test_user_tok = self.login("user", "pass")
         self.helper.join(room=self.room_id, user=self.test_user, tok=self.test_user_tok)
 
-    def _create_alias(self, user) -> None:
+    def _create_alias(self, user: str) -> None:
         # Create a new alias to this room.
         self.get_success(
             self.store.create_room_alias_association(
@@ -324,7 +325,7 @@ class CanonicalAliasTestCase(unittest.HomeserverTestCase):
         )
         return room_alias
 
-    def _set_canonical_alias(self, content) -> None:
+    def _set_canonical_alias(self, content: JsonDict) -> None:
         """Configure the canonical alias state on the room."""
         self.helper.send_state(
             self.room_id,
@@ -333,13 +334,15 @@ class CanonicalAliasTestCase(unittest.HomeserverTestCase):
             tok=self.admin_user_tok,
         )
 
-    def _get_canonical_alias(self):
+    def _get_canonical_alias(self) -> EventBase:
         """Get the canonical alias state of the room."""
-        return self.get_success(
+        result = self.get_success(
             self._storage_controllers.state.get_current_state_event(
                 self.room_id, EventTypes.CanonicalAlias, ""
             )
         )
+        assert result is not None
+        return result
 
     def test_remove_alias(self) -> None:
         """Removing an alias that is the canonical alias should remove it there too."""
@@ -349,8 +352,8 @@ class CanonicalAliasTestCase(unittest.HomeserverTestCase):
         )
 
         data = self._get_canonical_alias()
-        self.assertEqual(data["content"]["alias"], self.test_alias)
-        self.assertEqual(data["content"]["alt_aliases"], [self.test_alias])
+        self.assertEqual(data.content["alias"], self.test_alias)
+        self.assertEqual(data.content["alt_aliases"], [self.test_alias])
 
         # Finally, delete the alias.
         self.get_success(
@@ -360,8 +363,8 @@ class CanonicalAliasTestCase(unittest.HomeserverTestCase):
         )
 
         data = self._get_canonical_alias()
-        self.assertNotIn("alias", data["content"])
-        self.assertNotIn("alt_aliases", data["content"])
+        self.assertNotIn("alias", data.content)
+        self.assertNotIn("alt_aliases", data.content)
 
     def test_remove_other_alias(self) -> None:
         """Removing an alias listed as in alt_aliases should remove it there too."""
@@ -378,9 +381,9 @@ class CanonicalAliasTestCase(unittest.HomeserverTestCase):
         )
 
         data = self._get_canonical_alias()
-        self.assertEqual(data["content"]["alias"], self.test_alias)
+        self.assertEqual(data.content["alias"], self.test_alias)
         self.assertEqual(
-            data["content"]["alt_aliases"], [self.test_alias, other_test_alias]
+            data.content["alt_aliases"], [self.test_alias, other_test_alias]
         )
 
         # Delete the second alias.
@@ -391,8 +394,8 @@ class CanonicalAliasTestCase(unittest.HomeserverTestCase):
         )
 
         data = self._get_canonical_alias()
-        self.assertEqual(data["content"]["alias"], self.test_alias)
-        self.assertEqual(data["content"]["alt_aliases"], [self.test_alias])
+        self.assertEqual(data.content["alias"], self.test_alias)
+        self.assertEqual(data.content["alt_aliases"], [self.test_alias])
 
 
 class TestCreateAliasACL(unittest.HomeserverTestCase):
diff --git a/tests/handlers/test_e2e_room_keys.py b/tests/handlers/test_e2e_room_keys.py
index 9b7e7a8e9a..6c0b30de9e 100644
--- a/tests/handlers/test_e2e_room_keys.py
+++ b/tests/handlers/test_e2e_room_keys.py
@@ -17,7 +17,11 @@
 import copy
 from unittest import mock
 
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.errors import SynapseError
+from synapse.server import HomeServer
+from synapse.util import Clock
 
 from tests import unittest
 
@@ -39,14 +43,14 @@ room_keys = {
 
 
 class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
-    def make_homeserver(self, reactor, clock):
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
         return self.setup_test_homeserver(replication_layer=mock.Mock())
 
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.handler = hs.get_e2e_room_keys_handler()
         self.local_user = "@boris:" + hs.hostname
 
-    def test_get_missing_current_version_info(self):
+    def test_get_missing_current_version_info(self) -> None:
         """Check that we get a 404 if we ask for info about the current version
         if there is no version.
         """
@@ -56,7 +60,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_get_missing_version_info(self):
+    def test_get_missing_version_info(self) -> None:
         """Check that we get a 404 if we ask for info about a specific version
         if it doesn't exist.
         """
@@ -67,9 +71,9 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_create_version(self):
+    def test_create_version(self) -> None:
         """Check that we can create and then retrieve versions."""
-        res = self.get_success(
+        version = self.get_success(
             self.handler.create_version(
                 self.local_user,
                 {
@@ -78,7 +82,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
                 },
             )
         )
-        self.assertEqual(res, "1")
+        self.assertEqual(version, "1")
 
         # check we can retrieve it as the current version
         res = self.get_success(self.handler.get_version_info(self.local_user))
@@ -110,7 +114,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         )
 
         # upload a new one...
-        res = self.get_success(
+        version = self.get_success(
             self.handler.create_version(
                 self.local_user,
                 {
@@ -119,7 +123,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
                 },
             )
         )
-        self.assertEqual(res, "2")
+        self.assertEqual(version, "2")
 
         # check we can retrieve it as the current version
         res = self.get_success(self.handler.get_version_info(self.local_user))
@@ -134,7 +138,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
             },
         )
 
-    def test_update_version(self):
+    def test_update_version(self) -> None:
         """Check that we can update versions."""
         version = self.get_success(
             self.handler.create_version(
@@ -173,7 +177,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
             },
         )
 
-    def test_update_missing_version(self):
+    def test_update_missing_version(self) -> None:
         """Check that we get a 404 on updating nonexistent versions"""
         e = self.get_failure(
             self.handler.update_version(
@@ -190,7 +194,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_update_omitted_version(self):
+    def test_update_omitted_version(self) -> None:
         """Check that the update succeeds if the version is missing from the body"""
         version = self.get_success(
             self.handler.create_version(
@@ -227,7 +231,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
             },
         )
 
-    def test_update_bad_version(self):
+    def test_update_bad_version(self) -> None:
         """Check that we get a 400 if the version in the body doesn't match"""
         version = self.get_success(
             self.handler.create_version(
@@ -255,7 +259,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 400)
 
-    def test_delete_missing_version(self):
+    def test_delete_missing_version(self) -> None:
         """Check that we get a 404 on deleting nonexistent versions"""
         e = self.get_failure(
             self.handler.delete_version(self.local_user, "1"), SynapseError
@@ -263,15 +267,15 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_delete_missing_current_version(self):
+    def test_delete_missing_current_version(self) -> None:
         """Check that we get a 404 on deleting nonexistent current version"""
         e = self.get_failure(self.handler.delete_version(self.local_user), SynapseError)
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_delete_version(self):
+    def test_delete_version(self) -> None:
         """Check that we can create and then delete versions."""
-        res = self.get_success(
+        version = self.get_success(
             self.handler.create_version(
                 self.local_user,
                 {
@@ -280,7 +284,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
                 },
             )
         )
-        self.assertEqual(res, "1")
+        self.assertEqual(version, "1")
 
         # check we can delete it
         self.get_success(self.handler.delete_version(self.local_user, "1"))
@@ -292,7 +296,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_get_missing_backup(self):
+    def test_get_missing_backup(self) -> None:
         """Check that we get a 404 on querying missing backup"""
         e = self.get_failure(
             self.handler.get_room_keys(self.local_user, "bogus_version"), SynapseError
@@ -300,7 +304,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_get_missing_room_keys(self):
+    def test_get_missing_room_keys(self) -> None:
         """Check we get an empty response from an empty backup"""
         version = self.get_success(
             self.handler.create_version(
@@ -319,7 +323,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
     # TODO: test the locking semantics when uploading room_keys,
     # although this is probably best done in sytest
 
-    def test_upload_room_keys_no_versions(self):
+    def test_upload_room_keys_no_versions(self) -> None:
         """Check that we get a 404 on uploading keys when no versions are defined"""
         e = self.get_failure(
             self.handler.upload_room_keys(self.local_user, "no_version", room_keys),
@@ -328,7 +332,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_upload_room_keys_bogus_version(self):
+    def test_upload_room_keys_bogus_version(self) -> None:
         """Check that we get a 404 on uploading keys when an nonexistent version
         is specified
         """
@@ -350,7 +354,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 404)
 
-    def test_upload_room_keys_wrong_version(self):
+    def test_upload_room_keys_wrong_version(self) -> None:
         """Check that we get a 403 on uploading keys for an old version"""
         version = self.get_success(
             self.handler.create_version(
@@ -380,7 +384,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 403)
 
-    def test_upload_room_keys_insert(self):
+    def test_upload_room_keys_insert(self) -> None:
         """Check that we can insert and retrieve keys for a session"""
         version = self.get_success(
             self.handler.create_version(
@@ -416,7 +420,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
         )
         self.assertDictEqual(res, room_keys)
 
-    def test_upload_room_keys_merge(self):
+    def test_upload_room_keys_merge(self) -> None:
         """Check that we can upload a new room_key for an existing session and
         have it correctly merged"""
         version = self.get_success(
@@ -449,9 +453,11 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
             self.handler.upload_room_keys(self.local_user, version, new_room_keys)
         )
 
-        res = self.get_success(self.handler.get_room_keys(self.local_user, version))
+        res_keys = self.get_success(
+            self.handler.get_room_keys(self.local_user, version)
+        )
         self.assertEqual(
-            res["rooms"]["!abc:matrix.org"]["sessions"]["c0ff33"]["session_data"],
+            res_keys["rooms"]["!abc:matrix.org"]["sessions"]["c0ff33"]["session_data"],
             "SSBBTSBBIEZJU0gK",
         )
 
@@ -465,9 +471,12 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
             self.handler.upload_room_keys(self.local_user, version, new_room_keys)
         )
 
-        res = self.get_success(self.handler.get_room_keys(self.local_user, version))
+        res_keys = self.get_success(
+            self.handler.get_room_keys(self.local_user, version)
+        )
         self.assertEqual(
-            res["rooms"]["!abc:matrix.org"]["sessions"]["c0ff33"]["session_data"], "new"
+            res_keys["rooms"]["!abc:matrix.org"]["sessions"]["c0ff33"]["session_data"],
+            "new",
         )
 
         # the etag should NOT be equal now, since the key changed
@@ -483,9 +492,12 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
             self.handler.upload_room_keys(self.local_user, version, new_room_keys)
         )
 
-        res = self.get_success(self.handler.get_room_keys(self.local_user, version))
+        res_keys = self.get_success(
+            self.handler.get_room_keys(self.local_user, version)
+        )
         self.assertEqual(
-            res["rooms"]["!abc:matrix.org"]["sessions"]["c0ff33"]["session_data"], "new"
+            res_keys["rooms"]["!abc:matrix.org"]["sessions"]["c0ff33"]["session_data"],
+            "new",
         )
 
         # the etag should be the same since the session did not change
@@ -494,7 +506,7 @@ class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
 
         # TODO: check edge cases as well as the common variations here
 
-    def test_delete_room_keys(self):
+    def test_delete_room_keys(self) -> None:
         """Check that we can insert and delete keys for a session"""
         version = self.get_success(
             self.handler.create_version(
diff --git a/tests/handlers/test_federation.py b/tests/handlers/test_federation.py
index d00c69c229..cedbb9fafc 100644
--- a/tests/handlers/test_federation.py
+++ b/tests/handlers/test_federation.py
@@ -439,7 +439,7 @@ class FederationTestCase(unittest.FederatingHomeserverTestCase):
         user_id = self.register_user("kermit", "test")
         tok = self.login("kermit", "test")
 
-        def create_invite():
+        def create_invite() -> EventBase:
             room_id = self.helper.create_room_as(room_creator=user_id, tok=tok)
             room_version = self.get_success(self.store.get_room_version(room_id))
             return event_from_pdu_json(
diff --git a/tests/handlers/test_federation_event.py b/tests/handlers/test_federation_event.py
index e448cb1901..70ea4d15d4 100644
--- a/tests/handlers/test_federation_event.py
+++ b/tests/handlers/test_federation_event.py
@@ -14,6 +14,8 @@
 from typing import Optional
 from unittest import mock
 
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.errors import AuthError, StoreError
 from synapse.api.room_versions import RoomVersion
 from synapse.event_auth import (
@@ -26,8 +28,10 @@ from synapse.federation.transport.client import StateRequestResponse
 from synapse.logging.context import LoggingContext
 from synapse.rest import admin
 from synapse.rest.client import login, room
+from synapse.server import HomeServer
 from synapse.state.v2 import _mainline_sort, _reverse_topological_power_sort
 from synapse.types import JsonDict
+from synapse.util import Clock
 
 from tests import unittest
 from tests.test_utils import event_injection, make_awaitable
@@ -40,7 +44,7 @@ class FederationEventHandlerTests(unittest.FederatingHomeserverTestCase):
         room.register_servlets,
     ]
 
-    def make_homeserver(self, reactor, clock):
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
         # mock out the federation transport client
         self.mock_federation_transport_client = mock.Mock(
             spec=["get_room_state_ids", "get_room_state", "get_event", "backfill"]
@@ -165,7 +169,9 @@ class FederationEventHandlerTests(unittest.FederatingHomeserverTestCase):
             )
         else:
 
-            async def get_event(destination: str, event_id: str, timeout=None):
+            async def get_event(
+                destination: str, event_id: str, timeout: Optional[int] = None
+            ) -> JsonDict:
                 self.assertEqual(destination, self.OTHER_SERVER_NAME)
                 self.assertEqual(event_id, prev_event.event_id)
                 return {"pdus": [prev_event.get_pdu_json()]}
diff --git a/tests/handlers/test_message.py b/tests/handlers/test_message.py
index 99384837d0..c4727ab917 100644
--- a/tests/handlers/test_message.py
+++ b/tests/handlers/test_message.py
@@ -14,12 +14,16 @@
 import logging
 from typing import Tuple
 
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.constants import EventTypes
 from synapse.events import EventBase
 from synapse.events.snapshot import EventContext
 from synapse.rest import admin
 from synapse.rest.client import login, room
+from synapse.server import HomeServer
 from synapse.types import create_requester
+from synapse.util import Clock
 from synapse.util.stringutils import random_string
 
 from tests import unittest
@@ -35,7 +39,7 @@ class EventCreationTestCase(unittest.HomeserverTestCase):
         room.register_servlets,
     ]
 
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.handler = self.hs.get_event_creation_handler()
         self._persist_event_storage_controller = (
             self.hs.get_storage_controllers().persistence
@@ -94,7 +98,7 @@ class EventCreationTestCase(unittest.HomeserverTestCase):
             )
         )
 
-    def test_duplicated_txn_id(self):
+    def test_duplicated_txn_id(self) -> None:
         """Test that attempting to handle/persist an event with a transaction ID
         that has already been persisted correctly returns the old event and does
         *not* produce duplicate messages.
@@ -161,7 +165,7 @@ class EventCreationTestCase(unittest.HomeserverTestCase):
         # rather than the new one.
         self.assertEqual(ret_event1.event_id, ret_event4.event_id)
 
-    def test_duplicated_txn_id_one_call(self):
+    def test_duplicated_txn_id_one_call(self) -> None:
         """Test that we correctly handle duplicates that we try and persist at
         the same time.
         """
@@ -185,7 +189,9 @@ class EventCreationTestCase(unittest.HomeserverTestCase):
         self.assertEqual(len(events), 2)
         self.assertEqual(events[0].event_id, events[1].event_id)
 
-    def test_when_empty_prev_events_allowed_create_event_with_empty_prev_events(self):
+    def test_when_empty_prev_events_allowed_create_event_with_empty_prev_events(
+        self,
+    ) -> None:
         """When we set allow_no_prev_events=True, should be able to create a
         event without any prev_events (only auth_events).
         """
@@ -214,7 +220,7 @@ class EventCreationTestCase(unittest.HomeserverTestCase):
 
     def test_when_empty_prev_events_not_allowed_reject_event_with_empty_prev_events(
         self,
-    ):
+    ) -> None:
         """When we set allow_no_prev_events=False, shouldn't be able to create a
         event without any prev_events even if it has auth_events. Expect an
         exception to be raised.
@@ -245,7 +251,7 @@ class EventCreationTestCase(unittest.HomeserverTestCase):
 
     def test_when_empty_prev_events_allowed_reject_event_with_empty_prev_events_and_auth_events(
         self,
-    ):
+    ) -> None:
         """When we set allow_no_prev_events=True, should be able to create a
         event without any prev_events or auth_events. Expect an exception to be
         raised.
@@ -277,12 +283,12 @@ class ServerAclValidationTestCase(unittest.HomeserverTestCase):
         room.register_servlets,
     ]
 
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.user_id = self.register_user("tester", "foobar")
         self.access_token = self.login("tester", "foobar")
         self.room_id = self.helper.create_room_as(self.user_id, tok=self.access_token)
 
-    def test_allow_server_acl(self):
+    def test_allow_server_acl(self) -> None:
         """Test that sending an ACL that blocks everyone but ourselves works."""
 
         self.helper.send_state(
@@ -293,7 +299,7 @@ class ServerAclValidationTestCase(unittest.HomeserverTestCase):
             expect_code=200,
         )
 
-    def test_deny_server_acl_block_outselves(self):
+    def test_deny_server_acl_block_outselves(self) -> None:
         """Test that sending an ACL that blocks ourselves does not work."""
         self.helper.send_state(
             self.room_id,
@@ -303,7 +309,7 @@ class ServerAclValidationTestCase(unittest.HomeserverTestCase):
             expect_code=400,
         )
 
-    def test_deny_redact_server_acl(self):
+    def test_deny_redact_server_acl(self) -> None:
         """Test that attempting to redact an ACL is blocked."""
 
         body = self.helper.send_state(
diff --git a/tests/handlers/test_oidc.py b/tests/handlers/test_oidc.py
index 5955410524..49a1842b5c 100644
--- a/tests/handlers/test_oidc.py
+++ b/tests/handlers/test_oidc.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import os
-from typing import Any, Dict, Tuple
+from typing import Any, Awaitable, ContextManager, Dict, Optional, Tuple
 from unittest.mock import ANY, Mock, patch
 from urllib.parse import parse_qs, urlparse
 
@@ -23,7 +23,7 @@ from twisted.test.proto_helpers import MemoryReactor
 from synapse.handlers.sso import MappingException
 from synapse.http.site import SynapseRequest
 from synapse.server import HomeServer
-from synapse.types import UserID
+from synapse.types import JsonDict, UserID
 from synapse.util import Clock
 from synapse.util.macaroons import get_value_from_macaroon
 from synapse.util.stringutils import random_string
@@ -34,6 +34,10 @@ from tests.unittest import HomeserverTestCase, override_config
 
 try:
     import authlib  # noqa: F401
+    from authlib.oidc.core import UserInfo
+    from authlib.oidc.discovery import OpenIDProviderMetadata
+
+    from synapse.handlers.oidc import Token, UserAttributeDict
 
     HAS_OIDC = True
 except ImportError:
@@ -70,29 +74,37 @@ EXPLICIT_ENDPOINT_CONFIG = {
 
 class TestMappingProvider:
     @staticmethod
-    def parse_config(config):
-        return
+    def parse_config(config: JsonDict) -> None:
+        return None
 
-    def __init__(self, config):
+    def __init__(self, config: None):
         pass
 
-    def get_remote_user_id(self, userinfo):
+    def get_remote_user_id(self, userinfo: "UserInfo") -> str:
         return userinfo["sub"]
 
-    async def map_user_attributes(self, userinfo, token):
-        return {"localpart": userinfo["username"], "display_name": None}
+    async def map_user_attributes(
+        self, userinfo: "UserInfo", token: "Token"
+    ) -> "UserAttributeDict":
+        # This is testing not providing the full map.
+        return {"localpart": userinfo["username"], "display_name": None}  # type: ignore[typeddict-item]
 
     # Do not include get_extra_attributes to test backwards compatibility paths.
 
 
 class TestMappingProviderExtra(TestMappingProvider):
-    async def get_extra_attributes(self, userinfo, token):
+    async def get_extra_attributes(
+        self, userinfo: "UserInfo", token: "Token"
+    ) -> JsonDict:
         return {"phone": userinfo["phone"]}
 
 
 class TestMappingProviderFailures(TestMappingProvider):
-    async def map_user_attributes(self, userinfo, token, failures):
-        return {
+    # Superclass is testing the legacy interface for map_user_attributes.
+    async def map_user_attributes(  # type: ignore[override]
+        self, userinfo: "UserInfo", token: "Token", failures: int
+    ) -> "UserAttributeDict":
+        return {  # type: ignore[typeddict-item]
             "localpart": userinfo["username"] + (str(failures) if failures else ""),
             "display_name": None,
         }
@@ -161,13 +173,13 @@ class OidcHandlerTestCase(HomeserverTestCase):
         self.hs_patcher.stop()
         return super().tearDown()
 
-    def reset_mocks(self):
+    def reset_mocks(self) -> None:
         """Reset all the Mocks."""
         self.fake_server.reset_mocks()
         self.render_error.reset_mock()
         self.complete_sso_login.reset_mock()
 
-    def metadata_edit(self, values):
+    def metadata_edit(self, values: dict) -> ContextManager[Mock]:
         """Modify the result that will be returned by the well-known query"""
 
         metadata = self.fake_server.get_metadata()
@@ -196,7 +208,9 @@ class OidcHandlerTestCase(HomeserverTestCase):
         session = self._generate_oidc_session_token(state, nonce, client_redirect_url)
         return _build_callback_request(code, state, session), grant
 
-    def assertRenderedError(self, error, error_description=None):
+    def assertRenderedError(
+        self, error: str, error_description: Optional[str] = None
+    ) -> Tuple[Any, ...]:
         self.render_error.assert_called_once()
         args = self.render_error.call_args[0]
         self.assertEqual(args[1], error)
@@ -273,8 +287,8 @@ class OidcHandlerTestCase(HomeserverTestCase):
         """Provider metadatas are extensively validated."""
         h = self.provider
 
-        def force_load_metadata():
-            async def force_load():
+        def force_load_metadata() -> Awaitable[None]:
+            async def force_load() -> "OpenIDProviderMetadata":
                 return await h.load_metadata(force=True)
 
             return get_awaitable_result(force_load())
@@ -1198,7 +1212,7 @@ def _build_callback_request(
     state: str,
     session: str,
     ip_address: str = "10.0.0.1",
-):
+) -> Mock:
     """Builds a fake SynapseRequest to mock the browser callback
 
     Returns a Mock object which looks like the SynapseRequest we get from a browser
diff --git a/tests/handlers/test_password_providers.py b/tests/handlers/test_password_providers.py
index 75934b1707..0916de64f5 100644
--- a/tests/handlers/test_password_providers.py
+++ b/tests/handlers/test_password_providers.py
@@ -15,12 +15,13 @@
 """Tests for the password_auth_provider interface"""
 
 from http import HTTPStatus
-from typing import Any, Type, Union
+from typing import Any, Dict, List, Optional, Type, Union
 from unittest.mock import Mock
 
 import synapse
 from synapse.api.constants import LoginType
 from synapse.api.errors import Codes
+from synapse.handlers.account import AccountHandler
 from synapse.module_api import ModuleApi
 from synapse.rest.client import account, devices, login, logout, register
 from synapse.types import JsonDict, UserID
@@ -44,13 +45,13 @@ class LegacyPasswordOnlyAuthProvider:
     """A legacy password_provider which only implements `check_password`."""
 
     @staticmethod
-    def parse_config(self):
+    def parse_config(config: JsonDict) -> None:
         pass
 
-    def __init__(self, config, account_handler):
+    def __init__(self, config: None, account_handler: AccountHandler):
         pass
 
-    def check_password(self, *args):
+    def check_password(self, *args: str) -> Mock:
         return mock_password_provider.check_password(*args)
 
 
@@ -58,16 +59,16 @@ class LegacyCustomAuthProvider:
     """A legacy password_provider which implements a custom login type."""
 
     @staticmethod
-    def parse_config(self):
+    def parse_config(config: JsonDict) -> None:
         pass
 
-    def __init__(self, config, account_handler):
+    def __init__(self, config: None, account_handler: AccountHandler):
         pass
 
-    def get_supported_login_types(self):
+    def get_supported_login_types(self) -> Dict[str, List[str]]:
         return {"test.login_type": ["test_field"]}
 
-    def check_auth(self, *args):
+    def check_auth(self, *args: str) -> Mock:
         return mock_password_provider.check_auth(*args)
 
 
@@ -75,15 +76,15 @@ class CustomAuthProvider:
     """A module which registers password_auth_provider callbacks for a custom login type."""
 
     @staticmethod
-    def parse_config(self):
+    def parse_config(config: JsonDict) -> None:
         pass
 
-    def __init__(self, config, api: ModuleApi):
+    def __init__(self, config: None, api: ModuleApi):
         api.register_password_auth_provider_callbacks(
             auth_checkers={("test.login_type", ("test_field",)): self.check_auth}
         )
 
-    def check_auth(self, *args):
+    def check_auth(self, *args: Any) -> Mock:
         return mock_password_provider.check_auth(*args)
 
 
@@ -92,16 +93,16 @@ class LegacyPasswordCustomAuthProvider:
     as a custom type."""
 
     @staticmethod
-    def parse_config(self):
+    def parse_config(config: JsonDict) -> None:
         pass
 
-    def __init__(self, config, account_handler):
+    def __init__(self, config: None, account_handler: AccountHandler):
         pass
 
-    def get_supported_login_types(self):
+    def get_supported_login_types(self) -> Dict[str, List[str]]:
         return {"m.login.password": ["password"], "test.login_type": ["test_field"]}
 
-    def check_auth(self, *args):
+    def check_auth(self, *args: str) -> Mock:
         return mock_password_provider.check_auth(*args)
 
 
@@ -110,10 +111,10 @@ class PasswordCustomAuthProvider:
     as well as a password login"""
 
     @staticmethod
-    def parse_config(self):
+    def parse_config(config: JsonDict) -> None:
         pass
 
-    def __init__(self, config, api: ModuleApi):
+    def __init__(self, config: None, api: ModuleApi):
         api.register_password_auth_provider_callbacks(
             auth_checkers={
                 ("test.login_type", ("test_field",)): self.check_auth,
@@ -121,10 +122,10 @@ class PasswordCustomAuthProvider:
             }
         )
 
-    def check_auth(self, *args):
+    def check_auth(self, *args: Any) -> Mock:
         return mock_password_provider.check_auth(*args)
 
-    def check_pass(self, *args):
+    def check_pass(self, *args: str) -> Mock:
         return mock_password_provider.check_password(*args)
 
 
@@ -161,16 +162,16 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
     CALLBACK_USERNAME = "get_username_for_registration"
     CALLBACK_DISPLAYNAME = "get_displayname_for_registration"
 
-    def setUp(self):
+    def setUp(self) -> None:
         # we use a global mock device, so make sure we are starting with a clean slate
         mock_password_provider.reset_mock()
         super().setUp()
 
     @override_config(legacy_providers_config(LegacyPasswordOnlyAuthProvider))
-    def test_password_only_auth_progiver_login_legacy(self):
+    def test_password_only_auth_progiver_login_legacy(self) -> None:
         self.password_only_auth_provider_login_test_body()
 
-    def password_only_auth_provider_login_test_body(self):
+    def password_only_auth_provider_login_test_body(self) -> None:
         # login flows should only have m.login.password
         flows = self._get_login_flows()
         self.assertEqual(flows, [{"type": "m.login.password"}] + ADDITIONAL_LOGIN_FLOWS)
@@ -201,10 +202,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         )
 
     @override_config(legacy_providers_config(LegacyPasswordOnlyAuthProvider))
-    def test_password_only_auth_provider_ui_auth_legacy(self):
+    def test_password_only_auth_provider_ui_auth_legacy(self) -> None:
         self.password_only_auth_provider_ui_auth_test_body()
 
-    def password_only_auth_provider_ui_auth_test_body(self):
+    def password_only_auth_provider_ui_auth_test_body(self) -> None:
         """UI Auth should delegate correctly to the password provider"""
 
         # create the user, otherwise access doesn't work
@@ -238,10 +239,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         mock_password_provider.check_password.assert_called_once_with("@u:test", "p")
 
     @override_config(legacy_providers_config(LegacyPasswordOnlyAuthProvider))
-    def test_local_user_fallback_login_legacy(self):
+    def test_local_user_fallback_login_legacy(self) -> None:
         self.local_user_fallback_login_test_body()
 
-    def local_user_fallback_login_test_body(self):
+    def local_user_fallback_login_test_body(self) -> None:
         """rejected login should fall back to local db"""
         self.register_user("localuser", "localpass")
 
@@ -255,10 +256,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         self.assertEqual("@localuser:test", channel.json_body["user_id"])
 
     @override_config(legacy_providers_config(LegacyPasswordOnlyAuthProvider))
-    def test_local_user_fallback_ui_auth_legacy(self):
+    def test_local_user_fallback_ui_auth_legacy(self) -> None:
         self.local_user_fallback_ui_auth_test_body()
 
-    def local_user_fallback_ui_auth_test_body(self):
+    def local_user_fallback_ui_auth_test_body(self) -> None:
         """rejected login should fall back to local db"""
         self.register_user("localuser", "localpass")
 
@@ -298,10 +299,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"localdb_enabled": False},
         }
     )
-    def test_no_local_user_fallback_login_legacy(self):
+    def test_no_local_user_fallback_login_legacy(self) -> None:
         self.no_local_user_fallback_login_test_body()
 
-    def no_local_user_fallback_login_test_body(self):
+    def no_local_user_fallback_login_test_body(self) -> None:
         """localdb_enabled can block login with the local password"""
         self.register_user("localuser", "localpass")
 
@@ -320,10 +321,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"localdb_enabled": False},
         }
     )
-    def test_no_local_user_fallback_ui_auth_legacy(self):
+    def test_no_local_user_fallback_ui_auth_legacy(self) -> None:
         self.no_local_user_fallback_ui_auth_test_body()
 
-    def no_local_user_fallback_ui_auth_test_body(self):
+    def no_local_user_fallback_ui_auth_test_body(self) -> None:
         """localdb_enabled can block ui auth with the local password"""
         self.register_user("localuser", "localpass")
 
@@ -361,10 +362,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False},
         }
     )
-    def test_password_auth_disabled_legacy(self):
+    def test_password_auth_disabled_legacy(self) -> None:
         self.password_auth_disabled_test_body()
 
-    def password_auth_disabled_test_body(self):
+    def password_auth_disabled_test_body(self) -> None:
         """password auth doesn't work if it's disabled across the board"""
         # login flows should be empty
         flows = self._get_login_flows()
@@ -376,14 +377,14 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         mock_password_provider.check_password.assert_not_called()
 
     @override_config(legacy_providers_config(LegacyCustomAuthProvider))
-    def test_custom_auth_provider_login_legacy(self):
+    def test_custom_auth_provider_login_legacy(self) -> None:
         self.custom_auth_provider_login_test_body()
 
     @override_config(providers_config(CustomAuthProvider))
-    def test_custom_auth_provider_login(self):
+    def test_custom_auth_provider_login(self) -> None:
         self.custom_auth_provider_login_test_body()
 
-    def custom_auth_provider_login_test_body(self):
+    def custom_auth_provider_login_test_body(self) -> None:
         # login flows should have the custom flow and m.login.password, since we
         # haven't disabled local password lookup.
         # (password must come first, because reasons)
@@ -424,14 +425,14 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         )
 
     @override_config(legacy_providers_config(LegacyCustomAuthProvider))
-    def test_custom_auth_provider_ui_auth_legacy(self):
+    def test_custom_auth_provider_ui_auth_legacy(self) -> None:
         self.custom_auth_provider_ui_auth_test_body()
 
     @override_config(providers_config(CustomAuthProvider))
-    def test_custom_auth_provider_ui_auth(self):
+    def test_custom_auth_provider_ui_auth(self) -> None:
         self.custom_auth_provider_ui_auth_test_body()
 
-    def custom_auth_provider_ui_auth_test_body(self):
+    def custom_auth_provider_ui_auth_test_body(self) -> None:
         # register the user and log in twice, to get two devices
         self.register_user("localuser", "localpass")
         tok1 = self.login("localuser", "localpass")
@@ -486,14 +487,14 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         )
 
     @override_config(legacy_providers_config(LegacyCustomAuthProvider))
-    def test_custom_auth_provider_callback_legacy(self):
+    def test_custom_auth_provider_callback_legacy(self) -> None:
         self.custom_auth_provider_callback_test_body()
 
     @override_config(providers_config(CustomAuthProvider))
-    def test_custom_auth_provider_callback(self):
+    def test_custom_auth_provider_callback(self) -> None:
         self.custom_auth_provider_callback_test_body()
 
-    def custom_auth_provider_callback_test_body(self):
+    def custom_auth_provider_callback_test_body(self) -> None:
         callback = Mock(return_value=make_awaitable(None))
 
         mock_password_provider.check_auth.return_value = make_awaitable(
@@ -521,16 +522,16 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False},
         }
     )
-    def test_custom_auth_password_disabled_legacy(self):
+    def test_custom_auth_password_disabled_legacy(self) -> None:
         self.custom_auth_password_disabled_test_body()
 
     @override_config(
         {**providers_config(CustomAuthProvider), "password_config": {"enabled": False}}
     )
-    def test_custom_auth_password_disabled(self):
+    def test_custom_auth_password_disabled(self) -> None:
         self.custom_auth_password_disabled_test_body()
 
-    def custom_auth_password_disabled_test_body(self):
+    def custom_auth_password_disabled_test_body(self) -> None:
         """Test login with a custom auth provider where password login is disabled"""
         self.register_user("localuser", "localpass")
 
@@ -548,7 +549,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False, "localdb_enabled": False},
         }
     )
-    def test_custom_auth_password_disabled_localdb_enabled_legacy(self):
+    def test_custom_auth_password_disabled_localdb_enabled_legacy(self) -> None:
         self.custom_auth_password_disabled_localdb_enabled_test_body()
 
     @override_config(
@@ -557,10 +558,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False, "localdb_enabled": False},
         }
     )
-    def test_custom_auth_password_disabled_localdb_enabled(self):
+    def test_custom_auth_password_disabled_localdb_enabled(self) -> None:
         self.custom_auth_password_disabled_localdb_enabled_test_body()
 
-    def custom_auth_password_disabled_localdb_enabled_test_body(self):
+    def custom_auth_password_disabled_localdb_enabled_test_body(self) -> None:
         """Check the localdb_enabled == enabled == False
 
         Regression test for https://github.com/matrix-org/synapse/issues/8914: check
@@ -583,7 +584,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False},
         }
     )
-    def test_password_custom_auth_password_disabled_login_legacy(self):
+    def test_password_custom_auth_password_disabled_login_legacy(self) -> None:
         self.password_custom_auth_password_disabled_login_test_body()
 
     @override_config(
@@ -592,10 +593,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False},
         }
     )
-    def test_password_custom_auth_password_disabled_login(self):
+    def test_password_custom_auth_password_disabled_login(self) -> None:
         self.password_custom_auth_password_disabled_login_test_body()
 
-    def password_custom_auth_password_disabled_login_test_body(self):
+    def password_custom_auth_password_disabled_login_test_body(self) -> None:
         """log in with a custom auth provider which implements password, but password
         login is disabled"""
         self.register_user("localuser", "localpass")
@@ -615,7 +616,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False},
         }
     )
-    def test_password_custom_auth_password_disabled_ui_auth_legacy(self):
+    def test_password_custom_auth_password_disabled_ui_auth_legacy(self) -> None:
         self.password_custom_auth_password_disabled_ui_auth_test_body()
 
     @override_config(
@@ -624,10 +625,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"enabled": False},
         }
     )
-    def test_password_custom_auth_password_disabled_ui_auth(self):
+    def test_password_custom_auth_password_disabled_ui_auth(self) -> None:
         self.password_custom_auth_password_disabled_ui_auth_test_body()
 
-    def password_custom_auth_password_disabled_ui_auth_test_body(self):
+    def password_custom_auth_password_disabled_ui_auth_test_body(self) -> None:
         """UI Auth with a custom auth provider which implements password, but password
         login is disabled"""
         # register the user and log in twice via the test login type to get two devices,
@@ -689,7 +690,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"localdb_enabled": False},
         }
     )
-    def test_custom_auth_no_local_user_fallback_legacy(self):
+    def test_custom_auth_no_local_user_fallback_legacy(self) -> None:
         self.custom_auth_no_local_user_fallback_test_body()
 
     @override_config(
@@ -698,10 +699,10 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             "password_config": {"localdb_enabled": False},
         }
     )
-    def test_custom_auth_no_local_user_fallback(self):
+    def test_custom_auth_no_local_user_fallback(self) -> None:
         self.custom_auth_no_local_user_fallback_test_body()
 
-    def custom_auth_no_local_user_fallback_test_body(self):
+    def custom_auth_no_local_user_fallback_test_body(self) -> None:
         """Test login with a custom auth provider where the local db is disabled"""
         self.register_user("localuser", "localpass")
 
@@ -713,14 +714,16 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         channel = self._send_password_login("localuser", "localpass")
         self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
 
-    def test_on_logged_out(self):
+    def test_on_logged_out(self) -> None:
         """Tests that the on_logged_out callback is called when the user logs out."""
         self.register_user("rin", "password")
         tok = self.login("rin", "password")
 
         self.called = False
 
-        async def on_logged_out(user_id, device_id, access_token):
+        async def on_logged_out(
+            user_id: str, device_id: Optional[str], access_token: str
+        ) -> None:
             self.called = True
 
         on_logged_out = Mock(side_effect=on_logged_out)
@@ -738,7 +741,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         on_logged_out.assert_called_once()
         self.assertTrue(self.called)
 
-    def test_username(self):
+    def test_username(self) -> None:
         """Tests that the get_username_for_registration callback can define the username
         of a user when registering.
         """
@@ -763,7 +766,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         mxid = channel.json_body["user_id"]
         self.assertEqual(UserID.from_string(mxid).localpart, username + "-foo")
 
-    def test_username_uia(self):
+    def test_username_uia(self) -> None:
         """Tests that the get_username_for_registration callback is only called at the
         end of the UIA flow.
         """
@@ -782,7 +785,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
 
     # Set some email configuration so the test doesn't fail because of its absence.
     @override_config({"email": {"notif_from": "noreply@test"}})
-    def test_3pid_allowed(self):
+    def test_3pid_allowed(self) -> None:
         """Tests that an is_3pid_allowed_callbacks forbidding a 3PID makes Synapse refuse
         to bind the new 3PID, and that one allowing a 3PID makes Synapse accept to bind
         the 3PID. Also checks that the module is passed a boolean indicating whether the
@@ -791,7 +794,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         self._test_3pid_allowed("rin", False)
         self._test_3pid_allowed("kitay", True)
 
-    def test_displayname(self):
+    def test_displayname(self) -> None:
         """Tests that the get_displayname_for_registration callback can define the
         display name of a user when registering.
         """
@@ -820,7 +823,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
 
         self.assertEqual(display_name, username + "-foo")
 
-    def test_displayname_uia(self):
+    def test_displayname_uia(self) -> None:
         """Tests that the get_displayname_for_registration callback is only called at the
         end of the UIA flow.
         """
@@ -841,7 +844,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         # Check that the callback has been called.
         m.assert_called_once()
 
-    def _test_3pid_allowed(self, username: str, registration: bool):
+    def _test_3pid_allowed(self, username: str, registration: bool) -> None:
         """Tests that the "is_3pid_allowed" module callback is called correctly, using
         either /register or /account URLs depending on the arguments.
 
@@ -907,7 +910,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         client is trying to register.
         """
 
-        async def callback(uia_results, params):
+        async def callback(uia_results: JsonDict, params: JsonDict) -> str:
             self.assertIn(LoginType.DUMMY, uia_results)
             username = params["username"]
             return username + "-foo"
@@ -950,12 +953,13 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
     def _send_password_login(self, user: str, password: str) -> FakeChannel:
         return self._send_login(type="m.login.password", user=user, password=password)
 
-    def _send_login(self, type, user, **params) -> FakeChannel:
-        params.update({"identifier": {"type": "m.id.user", "user": user}, "type": type})
+    def _send_login(self, type: str, user: str, **extra_params: str) -> FakeChannel:
+        params = {"identifier": {"type": "m.id.user", "user": user}, "type": type}
+        params.update(extra_params)
         channel = self.make_request("POST", "/_matrix/client/r0/login", params)
         return channel
 
-    def _start_delete_device_session(self, access_token, device_id) -> str:
+    def _start_delete_device_session(self, access_token: str, device_id: str) -> str:
         """Make an initial delete device request, and return the UI Auth session ID"""
         channel = self._delete_device(access_token, device_id)
         self.assertEqual(channel.code, 401)
diff --git a/tests/handlers/test_presence.py b/tests/handlers/test_presence.py
index 584e7b8971..19f5322317 100644
--- a/tests/handlers/test_presence.py
+++ b/tests/handlers/test_presence.py
@@ -12,12 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Optional
+from typing import Optional, cast
 from unittest.mock import Mock, call
 
 from parameterized import parameterized
 from signedjson.key import generate_signing_key
 
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.constants import EventTypes, Membership, PresenceState
 from synapse.api.presence import UserPresenceState
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
@@ -35,7 +37,9 @@ from synapse.handlers.presence import (
 )
 from synapse.rest import admin
 from synapse.rest.client import room
-from synapse.types import UserID, get_domain_from_id
+from synapse.server import HomeServer
+from synapse.types import JsonDict, UserID, get_domain_from_id
+from synapse.util import Clock
 
 from tests import unittest
 from tests.replication._base import BaseMultiWorkerStreamTestCase
@@ -44,10 +48,12 @@ from tests.replication._base import BaseMultiWorkerStreamTestCase
 class PresenceUpdateTestCase(unittest.HomeserverTestCase):
     servlets = [admin.register_servlets]
 
-    def prepare(self, reactor, clock, homeserver):
+    def prepare(
+        self, reactor: MemoryReactor, clock: Clock, homeserver: HomeServer
+    ) -> None:
         self.store = homeserver.get_datastores().main
 
-    def test_offline_to_online(self):
+    def test_offline_to_online(self) -> None:
         wheel_timer = Mock()
         user_id = "@foo:bar"
         now = 5000000
@@ -85,7 +91,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
             any_order=True,
         )
 
-    def test_online_to_online(self):
+    def test_online_to_online(self) -> None:
         wheel_timer = Mock()
         user_id = "@foo:bar"
         now = 5000000
@@ -128,7 +134,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
             any_order=True,
         )
 
-    def test_online_to_online_last_active_noop(self):
+    def test_online_to_online_last_active_noop(self) -> None:
         wheel_timer = Mock()
         user_id = "@foo:bar"
         now = 5000000
@@ -173,7 +179,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
             any_order=True,
         )
 
-    def test_online_to_online_last_active(self):
+    def test_online_to_online_last_active(self) -> None:
         wheel_timer = Mock()
         user_id = "@foo:bar"
         now = 5000000
@@ -210,7 +216,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
             any_order=True,
         )
 
-    def test_remote_ping_timer(self):
+    def test_remote_ping_timer(self) -> None:
         wheel_timer = Mock()
         user_id = "@foo:bar"
         now = 5000000
@@ -244,7 +250,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
             any_order=True,
         )
 
-    def test_online_to_offline(self):
+    def test_online_to_offline(self) -> None:
         wheel_timer = Mock()
         user_id = "@foo:bar"
         now = 5000000
@@ -266,7 +272,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
 
         self.assertEqual(wheel_timer.insert.call_count, 0)
 
-    def test_online_to_idle(self):
+    def test_online_to_idle(self) -> None:
         wheel_timer = Mock()
         user_id = "@foo:bar"
         now = 5000000
@@ -300,7 +306,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
             any_order=True,
         )
 
-    def test_persisting_presence_updates(self):
+    def test_persisting_presence_updates(self) -> None:
         """Tests that the latest presence state for each user is persisted correctly"""
         # Create some test users and presence states for them
         presence_states = []
@@ -322,7 +328,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
         self.get_success(self.store.update_presence(presence_states))
 
         # Check that each update is present in the database
-        db_presence_states = self.get_success(
+        db_presence_states_raw = self.get_success(
             self.store.get_all_presence_updates(
                 instance_name="master",
                 last_id=0,
@@ -332,7 +338,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
         )
 
         # Extract presence update user ID and state information into lists of tuples
-        db_presence_states = [(ps[0], ps[1]) for _, ps in db_presence_states[0]]
+        db_presence_states = [(ps[0], ps[1]) for _, ps in db_presence_states_raw[0]]
         presence_states_compare = [(ps.user_id, ps.state) for ps in presence_states]
 
         # Compare what we put into the storage with what we got out.
@@ -343,7 +349,7 @@ class PresenceUpdateTestCase(unittest.HomeserverTestCase):
 class PresenceTimeoutTestCase(unittest.TestCase):
     """Tests different timers and that the timer does not change `status_msg` of user."""
 
-    def test_idle_timer(self):
+    def test_idle_timer(self) -> None:
         user_id = "@foo:bar"
         status_msg = "I'm here!"
         now = 5000000
@@ -363,7 +369,7 @@ class PresenceTimeoutTestCase(unittest.TestCase):
         self.assertEqual(new_state.state, PresenceState.UNAVAILABLE)
         self.assertEqual(new_state.status_msg, status_msg)
 
-    def test_busy_no_idle(self):
+    def test_busy_no_idle(self) -> None:
         """
         Tests that a user setting their presence to busy but idling doesn't turn their
         presence state into unavailable.
@@ -387,7 +393,7 @@ class PresenceTimeoutTestCase(unittest.TestCase):
         self.assertEqual(new_state.state, PresenceState.BUSY)
         self.assertEqual(new_state.status_msg, status_msg)
 
-    def test_sync_timeout(self):
+    def test_sync_timeout(self) -> None:
         user_id = "@foo:bar"
         status_msg = "I'm here!"
         now = 5000000
@@ -407,7 +413,7 @@ class PresenceTimeoutTestCase(unittest.TestCase):
         self.assertEqual(new_state.state, PresenceState.OFFLINE)
         self.assertEqual(new_state.status_msg, status_msg)
 
-    def test_sync_online(self):
+    def test_sync_online(self) -> None:
         user_id = "@foo:bar"
         status_msg = "I'm here!"
         now = 5000000
@@ -429,7 +435,7 @@ class PresenceTimeoutTestCase(unittest.TestCase):
         self.assertEqual(new_state.state, PresenceState.ONLINE)
         self.assertEqual(new_state.status_msg, status_msg)
 
-    def test_federation_ping(self):
+    def test_federation_ping(self) -> None:
         user_id = "@foo:bar"
         status_msg = "I'm here!"
         now = 5000000
@@ -448,7 +454,7 @@ class PresenceTimeoutTestCase(unittest.TestCase):
         self.assertIsNotNone(new_state)
         self.assertEqual(state, new_state)
 
-    def test_no_timeout(self):
+    def test_no_timeout(self) -> None:
         user_id = "@foo:bar"
         now = 5000000
 
@@ -464,7 +470,7 @@ class PresenceTimeoutTestCase(unittest.TestCase):
 
         self.assertIsNone(new_state)
 
-    def test_federation_timeout(self):
+    def test_federation_timeout(self) -> None:
         user_id = "@foo:bar"
         status_msg = "I'm here!"
         now = 5000000
@@ -487,7 +493,7 @@ class PresenceTimeoutTestCase(unittest.TestCase):
         self.assertEqual(new_state.state, PresenceState.OFFLINE)
         self.assertEqual(new_state.status_msg, status_msg)
 
-    def test_last_active(self):
+    def test_last_active(self) -> None:
         user_id = "@foo:bar"
         status_msg = "I'm here!"
         now = 5000000
@@ -508,15 +514,15 @@ class PresenceTimeoutTestCase(unittest.TestCase):
 
 
 class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.presence_handler = hs.get_presence_handler()
         self.clock = hs.get_clock()
 
-    def test_external_process_timeout(self):
+    def test_external_process_timeout(self) -> None:
         """Test that if an external process doesn't update the records for a while
         we time out their syncing users presence.
         """
-        process_id = 1
+        process_id = "1"
         user_id = "@test:server"
 
         # Notify handler that a user is now syncing.
@@ -544,7 +550,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
         )
         self.assertEqual(state.state, PresenceState.OFFLINE)
 
-    def test_user_goes_offline_by_timeout_status_msg_remain(self):
+    def test_user_goes_offline_by_timeout_status_msg_remain(self) -> None:
         """Test that if a user doesn't update the records for a while
         users presence goes `OFFLINE` because of timeout and `status_msg` remains.
         """
@@ -576,7 +582,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
         self.assertEqual(state.state, PresenceState.OFFLINE)
         self.assertEqual(state.status_msg, status_msg)
 
-    def test_user_goes_offline_manually_with_no_status_msg(self):
+    def test_user_goes_offline_manually_with_no_status_msg(self) -> None:
         """Test that if a user change presence manually to `OFFLINE`
         and no status is set, that `status_msg` is `None`.
         """
@@ -601,7 +607,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
         self.assertEqual(state.state, PresenceState.OFFLINE)
         self.assertEqual(state.status_msg, None)
 
-    def test_user_goes_offline_manually_with_status_msg(self):
+    def test_user_goes_offline_manually_with_status_msg(self) -> None:
         """Test that if a user change presence manually to `OFFLINE`
         and a status is set, that `status_msg` appears.
         """
@@ -618,7 +624,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
             user_id, PresenceState.OFFLINE, "And now here."
         )
 
-    def test_user_reset_online_with_no_status(self):
+    def test_user_reset_online_with_no_status(self) -> None:
         """Test that if a user set again the presence manually
         and no status is set, that `status_msg` is `None`.
         """
@@ -644,7 +650,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
         self.assertEqual(state.state, PresenceState.ONLINE)
         self.assertEqual(state.status_msg, None)
 
-    def test_set_presence_with_status_msg_none(self):
+    def test_set_presence_with_status_msg_none(self) -> None:
         """Test that if a user set again the presence manually
         and status is `None`, that `status_msg` is `None`.
         """
@@ -659,7 +665,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
         # Mark user as online and `status_msg = None`
         self._set_presencestate_with_status_msg(user_id, PresenceState.ONLINE, None)
 
-    def test_set_presence_from_syncing_not_set(self):
+    def test_set_presence_from_syncing_not_set(self) -> None:
         """Test that presence is not set by syncing if affect_presence is false"""
         user_id = "@test:server"
         status_msg = "I'm here!"
@@ -680,7 +686,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
         # and status message should still be the same
         self.assertEqual(state.status_msg, status_msg)
 
-    def test_set_presence_from_syncing_is_set(self):
+    def test_set_presence_from_syncing_is_set(self) -> None:
         """Test that presence is set by syncing if affect_presence is true"""
         user_id = "@test:server"
         status_msg = "I'm here!"
@@ -699,7 +705,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
         # we should now be online
         self.assertEqual(state.state, PresenceState.ONLINE)
 
-    def test_set_presence_from_syncing_keeps_status(self):
+    def test_set_presence_from_syncing_keeps_status(self) -> None:
         """Test that presence set by syncing retains status message"""
         user_id = "@test:server"
         status_msg = "I'm here!"
@@ -726,7 +732,9 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
             },
         }
     )
-    def test_set_presence_from_syncing_keeps_busy(self, test_with_workers: bool):
+    def test_set_presence_from_syncing_keeps_busy(
+        self, test_with_workers: bool
+    ) -> None:
         """Test that presence set by syncing doesn't affect busy status
 
         Args:
@@ -767,7 +775,7 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
 
     def _set_presencestate_with_status_msg(
         self, user_id: str, state: str, status_msg: Optional[str]
-    ):
+    ) -> None:
         """Set a PresenceState and status_msg and check the result.
 
         Args:
@@ -790,14 +798,14 @@ class PresenceHandlerTestCase(BaseMultiWorkerStreamTestCase):
 
 
 class PresenceFederationQueueTestCase(unittest.HomeserverTestCase):
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.presence_handler = hs.get_presence_handler()
         self.clock = hs.get_clock()
         self.instance_name = hs.get_instance_name()
 
         self.queue = self.presence_handler.get_federation_queue()
 
-    def test_send_and_get(self):
+    def test_send_and_get(self) -> None:
         state1 = UserPresenceState.default("@user1:test")
         state2 = UserPresenceState.default("@user2:test")
         state3 = UserPresenceState.default("@user3:test")
@@ -834,7 +842,7 @@ class PresenceFederationQueueTestCase(unittest.HomeserverTestCase):
         self.assertFalse(limited)
         self.assertCountEqual(rows, [])
 
-    def test_send_and_get_split(self):
+    def test_send_and_get_split(self) -> None:
         state1 = UserPresenceState.default("@user1:test")
         state2 = UserPresenceState.default("@user2:test")
         state3 = UserPresenceState.default("@user3:test")
@@ -877,7 +885,7 @@ class PresenceFederationQueueTestCase(unittest.HomeserverTestCase):
 
         self.assertCountEqual(rows, expected_rows)
 
-    def test_clear_queue_all(self):
+    def test_clear_queue_all(self) -> None:
         state1 = UserPresenceState.default("@user1:test")
         state2 = UserPresenceState.default("@user2:test")
         state3 = UserPresenceState.default("@user3:test")
@@ -921,7 +929,7 @@ class PresenceFederationQueueTestCase(unittest.HomeserverTestCase):
 
         self.assertCountEqual(rows, expected_rows)
 
-    def test_partially_clear_queue(self):
+    def test_partially_clear_queue(self) -> None:
         state1 = UserPresenceState.default("@user1:test")
         state2 = UserPresenceState.default("@user2:test")
         state3 = UserPresenceState.default("@user3:test")
@@ -982,7 +990,7 @@ class PresenceJoinTestCase(unittest.HomeserverTestCase):
 
     servlets = [room.register_servlets]
 
-    def make_homeserver(self, reactor, clock):
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
         hs = self.setup_test_homeserver(
             "server",
             federation_http_client=None,
@@ -990,14 +998,14 @@ class PresenceJoinTestCase(unittest.HomeserverTestCase):
         )
         return hs
 
-    def default_config(self):
+    def default_config(self) -> JsonDict:
         config = super().default_config()
         # Enable federation sending on the main process.
         config["federation_sender_instances"] = None
         return config
 
-    def prepare(self, reactor, clock, hs):
-        self.federation_sender = hs.get_federation_sender()
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        self.federation_sender = cast(Mock, hs.get_federation_sender())
         self.event_builder_factory = hs.get_event_builder_factory()
         self.federation_event_handler = hs.get_federation_event_handler()
         self.presence_handler = hs.get_presence_handler()
@@ -1013,7 +1021,7 @@ class PresenceJoinTestCase(unittest.HomeserverTestCase):
         # random key to use.
         self.random_signing_key = generate_signing_key("ver")
 
-    def test_remote_joins(self):
+    def test_remote_joins(self) -> None:
         # We advance time to something that isn't 0, as we use 0 as a special
         # value.
         self.reactor.advance(1000000000000)
@@ -1061,7 +1069,7 @@ class PresenceJoinTestCase(unittest.HomeserverTestCase):
             destinations={"server3"}, states=[expected_state]
         )
 
-    def test_remote_gets_presence_when_local_user_joins(self):
+    def test_remote_gets_presence_when_local_user_joins(self) -> None:
         # We advance time to something that isn't 0, as we use 0 as a special
         # value.
         self.reactor.advance(1000000000000)
@@ -1110,7 +1118,7 @@ class PresenceJoinTestCase(unittest.HomeserverTestCase):
             destinations={"server2", "server3"}, states=[expected_state]
         )
 
-    def _add_new_user(self, room_id, user_id):
+    def _add_new_user(self, room_id: str, user_id: str) -> None:
         """Add new user to the room by creating an event and poking the federation API."""
 
         hostname = get_domain_from_id(user_id)
diff --git a/tests/handlers/test_profile.py b/tests/handlers/test_profile.py
index 675aa023ac..7c174782da 100644
--- a/tests/handlers/test_profile.py
+++ b/tests/handlers/test_profile.py
@@ -332,7 +332,7 @@ class ProfileTestCase(unittest.HomeserverTestCase):
     @unittest.override_config(
         {"server_name": "test:8888", "allowed_avatar_mimetypes": ["image/png"]}
     )
-    def test_avatar_constraint_on_local_server_with_port(self):
+    def test_avatar_constraint_on_local_server_with_port(self) -> None:
         """Test that avatar metadata is correctly fetched when the media is on a local
         server and the server has an explicit port.
 
@@ -376,7 +376,7 @@ class ProfileTestCase(unittest.HomeserverTestCase):
             self.get_success(self.handler.check_avatar_size_and_mime_type(remote_mxc))
         )
 
-    def _setup_local_files(self, names_and_props: Dict[str, Dict[str, Any]]):
+    def _setup_local_files(self, names_and_props: Dict[str, Dict[str, Any]]) -> None:
         """Stores metadata about files in the database.
 
         Args:
diff --git a/tests/handlers/test_receipts.py b/tests/handlers/test_receipts.py
index b55238650c..f60400ff8d 100644
--- a/tests/handlers/test_receipts.py
+++ b/tests/handlers/test_receipts.py
@@ -15,14 +15,18 @@
 from copy import deepcopy
 from typing import List
 
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.constants import EduTypes, ReceiptTypes
+from synapse.server import HomeServer
 from synapse.types import JsonDict
+from synapse.util import Clock
 
 from tests import unittest
 
 
 class ReceiptsTestCase(unittest.HomeserverTestCase):
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.event_source = hs.get_event_sources().sources.receipt
 
     def test_filters_out_private_receipt(self) -> None:
diff --git a/tests/handlers/test_register.py b/tests/handlers/test_register.py
index 765df75d91..b9332d97dc 100644
--- a/tests/handlers/test_register.py
+++ b/tests/handlers/test_register.py
@@ -12,8 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any, Collection, List, Optional, Tuple
 from unittest.mock import Mock
 
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.auth import Auth
 from synapse.api.constants import UserTypes
 from synapse.api.errors import (
@@ -22,8 +25,18 @@ from synapse.api.errors import (
     ResourceLimitError,
     SynapseError,
 )
+from synapse.module_api import ModuleApi
+from synapse.server import HomeServer
 from synapse.spam_checker_api import RegistrationBehaviour
-from synapse.types import RoomAlias, RoomID, UserID, create_requester
+from synapse.types import (
+    JsonDict,
+    Requester,
+    RoomAlias,
+    RoomID,
+    UserID,
+    create_requester,
+)
+from synapse.util import Clock
 
 from tests.test_utils import make_awaitable
 from tests.unittest import override_config
@@ -33,94 +46,98 @@ from .. import unittest
 
 
 class TestSpamChecker:
-    def __init__(self, config, api):
+    def __init__(self, config: None, api: ModuleApi):
         api.register_spam_checker_callbacks(
             check_registration_for_spam=self.check_registration_for_spam,
         )
 
     @staticmethod
-    def parse_config(config):
-        return config
+    def parse_config(config: JsonDict) -> None:
+        return None
 
     async def check_registration_for_spam(
         self,
-        email_threepid,
-        username,
-        request_info,
-        auth_provider_id,
-    ):
+        email_threepid: Optional[dict],
+        username: Optional[str],
+        request_info: Collection[Tuple[str, str]],
+        auth_provider_id: Optional[str],
+    ) -> RegistrationBehaviour:
         pass
 
 
 class DenyAll(TestSpamChecker):
     async def check_registration_for_spam(
         self,
-        email_threepid,
-        username,
-        request_info,
-        auth_provider_id,
-    ):
+        email_threepid: Optional[dict],
+        username: Optional[str],
+        request_info: Collection[Tuple[str, str]],
+        auth_provider_id: Optional[str],
+    ) -> RegistrationBehaviour:
         return RegistrationBehaviour.DENY
 
 
 class BanAll(TestSpamChecker):
     async def check_registration_for_spam(
         self,
-        email_threepid,
-        username,
-        request_info,
-        auth_provider_id,
-    ):
+        email_threepid: Optional[dict],
+        username: Optional[str],
+        request_info: Collection[Tuple[str, str]],
+        auth_provider_id: Optional[str],
+    ) -> RegistrationBehaviour:
         return RegistrationBehaviour.SHADOW_BAN
 
 
 class BanBadIdPUser(TestSpamChecker):
     async def check_registration_for_spam(
-        self, email_threepid, username, request_info, auth_provider_id=None
-    ):
+        self,
+        email_threepid: Optional[dict],
+        username: Optional[str],
+        request_info: Collection[Tuple[str, str]],
+        auth_provider_id: Optional[str] = None,
+    ) -> RegistrationBehaviour:
         # Reject any user coming from CAS and whose username contains profanity
-        if auth_provider_id == "cas" and "flimflob" in username:
+        if auth_provider_id == "cas" and username and "flimflob" in username:
             return RegistrationBehaviour.DENY
         return RegistrationBehaviour.ALLOW
 
 
 class TestLegacyRegistrationSpamChecker:
-    def __init__(self, config, api):
+    def __init__(self, config: None, api: ModuleApi):
         pass
 
     async def check_registration_for_spam(
         self,
-        email_threepid,
-        username,
-        request_info,
-    ):
+        email_threepid: Optional[dict],
+        username: Optional[str],
+        request_info: Collection[Tuple[str, str]],
+    ) -> RegistrationBehaviour:
         pass
 
 
 class LegacyAllowAll(TestLegacyRegistrationSpamChecker):
     async def check_registration_for_spam(
         self,
-        email_threepid,
-        username,
-        request_info,
-    ):
+        email_threepid: Optional[dict],
+        username: Optional[str],
+        request_info: Collection[Tuple[str, str]],
+    ) -> RegistrationBehaviour:
         return RegistrationBehaviour.ALLOW
 
 
 class LegacyDenyAll(TestLegacyRegistrationSpamChecker):
     async def check_registration_for_spam(
         self,
-        email_threepid,
-        username,
-        request_info,
-    ):
+        email_threepid: Optional[dict],
+        username: Optional[str],
+        request_info: Collection[Tuple[str, str]],
+    ) -> RegistrationBehaviour:
         return RegistrationBehaviour.DENY
 
 
 class RegistrationTestCase(unittest.HomeserverTestCase):
     """Tests the RegistrationHandler."""
 
-    def make_homeserver(self, reactor, clock):
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
         hs_config = self.default_config()
 
         # some of the tests rely on us having a user consent version
@@ -145,7 +162,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
 
         return hs
 
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.handler = self.hs.get_registration_handler()
         self.store = self.hs.get_datastores().main
         self.lots_of_users = 100
@@ -153,7 +170,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
 
         self.requester = create_requester("@requester:test")
 
-    def test_user_is_created_and_logged_in_if_doesnt_exist(self):
+    def test_user_is_created_and_logged_in_if_doesnt_exist(self) -> None:
         frank = UserID.from_string("@frank:test")
         user_id = frank.to_string()
         requester = create_requester(user_id)
@@ -164,7 +181,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.assertIsInstance(result_token, str)
         self.assertGreater(len(result_token), 20)
 
-    def test_if_user_exists(self):
+    def test_if_user_exists(self) -> None:
         store = self.hs.get_datastores().main
         frank = UserID.from_string("@frank:test")
         self.get_success(
@@ -180,12 +197,12 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.assertTrue(result_token is not None)
 
     @override_config({"limit_usage_by_mau": False})
-    def test_mau_limits_when_disabled(self):
+    def test_mau_limits_when_disabled(self) -> None:
         # Ensure does not throw exception
         self.get_success(self.get_or_create_user(self.requester, "a", "display_name"))
 
     @override_config({"limit_usage_by_mau": True})
-    def test_get_or_create_user_mau_not_blocked(self):
+    def test_get_or_create_user_mau_not_blocked(self) -> None:
         self.store.count_monthly_users = Mock(
             return_value=make_awaitable(self.hs.config.server.max_mau_value - 1)
         )
@@ -193,7 +210,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.get_success(self.get_or_create_user(self.requester, "c", "User"))
 
     @override_config({"limit_usage_by_mau": True})
-    def test_get_or_create_user_mau_blocked(self):
+    def test_get_or_create_user_mau_blocked(self) -> None:
         self.store.get_monthly_active_count = Mock(
             return_value=make_awaitable(self.lots_of_users)
         )
@@ -211,7 +228,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         )
 
     @override_config({"limit_usage_by_mau": True})
-    def test_register_mau_blocked(self):
+    def test_register_mau_blocked(self) -> None:
         self.store.get_monthly_active_count = Mock(
             return_value=make_awaitable(self.lots_of_users)
         )
@@ -229,7 +246,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
     @override_config(
         {"auto_join_rooms": ["#room:test"], "auto_join_rooms_for_guests": False}
     )
-    def test_auto_join_rooms_for_guests(self):
+    def test_auto_join_rooms_for_guests(self) -> None:
         user_id = self.get_success(
             self.handler.register_user(localpart="jeff", make_guest=True),
         )
@@ -237,7 +254,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.assertEqual(len(rooms), 0)
 
     @override_config({"auto_join_rooms": ["#room:test"]})
-    def test_auto_create_auto_join_rooms(self):
+    def test_auto_create_auto_join_rooms(self) -> None:
         room_alias_str = "#room:test"
         user_id = self.get_success(self.handler.register_user(localpart="jeff"))
         rooms = self.get_success(self.store.get_rooms_for_user(user_id))
@@ -249,7 +266,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.assertEqual(len(rooms), 1)
 
     @override_config({"auto_join_rooms": []})
-    def test_auto_create_auto_join_rooms_with_no_rooms(self):
+    def test_auto_create_auto_join_rooms_with_no_rooms(self) -> None:
         frank = UserID.from_string("@frank:test")
         user_id = self.get_success(self.handler.register_user(frank.localpart))
         self.assertEqual(user_id, frank.to_string())
@@ -257,7 +274,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.assertEqual(len(rooms), 0)
 
     @override_config({"auto_join_rooms": ["#room:another"]})
-    def test_auto_create_auto_join_where_room_is_another_domain(self):
+    def test_auto_create_auto_join_where_room_is_another_domain(self) -> None:
         frank = UserID.from_string("@frank:test")
         user_id = self.get_success(self.handler.register_user(frank.localpart))
         self.assertEqual(user_id, frank.to_string())
@@ -267,13 +284,13 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
     @override_config(
         {"auto_join_rooms": ["#room:test"], "autocreate_auto_join_rooms": False}
     )
-    def test_auto_create_auto_join_where_auto_create_is_false(self):
+    def test_auto_create_auto_join_where_auto_create_is_false(self) -> None:
         user_id = self.get_success(self.handler.register_user(localpart="jeff"))
         rooms = self.get_success(self.store.get_rooms_for_user(user_id))
         self.assertEqual(len(rooms), 0)
 
     @override_config({"auto_join_rooms": ["#room:test"]})
-    def test_auto_create_auto_join_rooms_when_user_is_not_a_real_user(self):
+    def test_auto_create_auto_join_rooms_when_user_is_not_a_real_user(self) -> None:
         room_alias_str = "#room:test"
         self.store.is_real_user = Mock(return_value=make_awaitable(False))
         user_id = self.get_success(self.handler.register_user(localpart="support"))
@@ -284,7 +301,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.get_failure(directory_handler.get_association(room_alias), SynapseError)
 
     @override_config({"auto_join_rooms": ["#room:test"]})
-    def test_auto_create_auto_join_rooms_when_user_is_the_first_real_user(self):
+    def test_auto_create_auto_join_rooms_when_user_is_the_first_real_user(self) -> None:
         room_alias_str = "#room:test"
 
         self.store.count_real_users = Mock(return_value=make_awaitable(1))
@@ -299,7 +316,9 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         self.assertEqual(len(rooms), 1)
 
     @override_config({"auto_join_rooms": ["#room:test"]})
-    def test_auto_create_auto_join_rooms_when_user_is_not_the_first_real_user(self):
+    def test_auto_create_auto_join_rooms_when_user_is_not_the_first_real_user(
+        self,
+    ) -> None:
         self.store.count_real_users = Mock(return_value=make_awaitable(2))
         self.store.is_real_user = Mock(return_value=make_awaitable(True))
         user_id = self.get_success(self.handler.register_user(localpart="real"))
@@ -312,7 +331,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             "autocreate_auto_join_rooms_federated": False,
         }
     )
-    def test_auto_create_auto_join_rooms_federated(self):
+    def test_auto_create_auto_join_rooms_federated(self) -> None:
         """
         Auto-created rooms that are private require an invite to go to the user
         (instead of directly joining it).
@@ -339,7 +358,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
     @override_config(
         {"auto_join_rooms": ["#room:test"], "auto_join_mxid_localpart": "support"}
     )
-    def test_auto_join_mxid_localpart(self):
+    def test_auto_join_mxid_localpart(self) -> None:
         """
         Ensure the user still needs up in the room created by a different user.
         """
@@ -376,7 +395,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             "auto_join_mxid_localpart": "support",
         }
     )
-    def test_auto_create_auto_join_room_preset(self):
+    def test_auto_create_auto_join_room_preset(self) -> None:
         """
         Auto-created rooms that are private require an invite to go to the user
         (instead of directly joining it).
@@ -416,7 +435,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             "auto_join_mxid_localpart": "support",
         }
     )
-    def test_auto_create_auto_join_room_preset_guest(self):
+    def test_auto_create_auto_join_room_preset_guest(self) -> None:
         """
         Auto-created rooms that are private require an invite to go to the user
         (instead of directly joining it).
@@ -454,7 +473,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             "auto_join_mxid_localpart": "support",
         }
     )
-    def test_auto_create_auto_join_room_preset_invalid_permissions(self):
+    def test_auto_create_auto_join_room_preset_invalid_permissions(self) -> None:
         """
         Auto-created rooms that are private require an invite, check that
         registration doesn't completely break if the inviter doesn't have proper
@@ -525,7 +544,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             "auto_join_rooms": ["#room:test"],
         },
     )
-    def test_auto_create_auto_join_where_no_consent(self):
+    def test_auto_create_auto_join_where_no_consent(self) -> None:
         """Test to ensure that the first user is not auto-joined to a room if
         they have not given general consent.
         """
@@ -550,19 +569,19 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         rooms = self.get_success(self.store.get_rooms_for_user(user_id))
         self.assertEqual(len(rooms), 1)
 
-    def test_register_support_user(self):
+    def test_register_support_user(self) -> None:
         user_id = self.get_success(
             self.handler.register_user(localpart="user", user_type=UserTypes.SUPPORT)
         )
         d = self.store.is_support_user(user_id)
         self.assertTrue(self.get_success(d))
 
-    def test_register_not_support_user(self):
+    def test_register_not_support_user(self) -> None:
         user_id = self.get_success(self.handler.register_user(localpart="user"))
         d = self.store.is_support_user(user_id)
         self.assertFalse(self.get_success(d))
 
-    def test_invalid_user_id_length(self):
+    def test_invalid_user_id_length(self) -> None:
         invalid_user_id = "x" * 256
         self.get_failure(
             self.handler.register_user(localpart=invalid_user_id), SynapseError
@@ -577,7 +596,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             ]
         }
     )
-    def test_spam_checker_deny(self):
+    def test_spam_checker_deny(self) -> None:
         """A spam checker can deny registration, which results in an error."""
         self.get_failure(self.handler.register_user(localpart="user"), SynapseError)
 
@@ -590,7 +609,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             ]
         }
     )
-    def test_spam_checker_legacy_allow(self):
+    def test_spam_checker_legacy_allow(self) -> None:
         """Tests that a legacy spam checker implementing the legacy 3-arg version of the
         check_registration_for_spam callback is correctly called.
 
@@ -610,7 +629,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             ]
         }
     )
-    def test_spam_checker_legacy_deny(self):
+    def test_spam_checker_legacy_deny(self) -> None:
         """Tests that a legacy spam checker implementing the legacy 3-arg version of the
         check_registration_for_spam callback is correctly called.
 
@@ -630,7 +649,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             ]
         }
     )
-    def test_spam_checker_shadow_ban(self):
+    def test_spam_checker_shadow_ban(self) -> None:
         """A spam checker can choose to shadow-ban a user, which allows registration to succeed."""
         user_id = self.get_success(self.handler.register_user(localpart="user"))
 
@@ -660,7 +679,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             ]
         }
     )
-    def test_spam_checker_receives_sso_type(self):
+    def test_spam_checker_receives_sso_type(self) -> None:
         """Test rejecting registration based on SSO type"""
         f = self.get_failure(
             self.handler.register_user(localpart="bobflimflob", auth_provider_id="cas"),
@@ -678,8 +697,12 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         )
 
     async def get_or_create_user(
-        self, requester, localpart, displayname, password_hash=None
-    ):
+        self,
+        requester: Requester,
+        localpart: str,
+        displayname: Optional[str],
+        password_hash: Optional[str] = None,
+    ) -> Tuple[str, str]:
         """Creates a new user if the user does not exist,
         else revokes all previous access tokens and generates a new one.
 
@@ -734,13 +757,15 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
 class RemoteAutoJoinTestCase(unittest.HomeserverTestCase):
     """Tests auto-join on remote rooms."""
 
-    def make_homeserver(self, reactor, clock):
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
         self.room_id = "!roomid:remotetest"
 
-        async def update_membership(*args, **kwargs):
+        async def update_membership(*args: Any, **kwargs: Any) -> None:
             pass
 
-        async def lookup_room_alias(*args, **kwargs):
+        async def lookup_room_alias(
+            *args: Any, **kwargs: Any
+        ) -> Tuple[RoomID, List[str]]:
             return RoomID.from_string(self.room_id), ["remotetest"]
 
         self.room_member_handler = Mock(spec=["update_membership", "lookup_room_alias"])
@@ -750,12 +775,12 @@ class RemoteAutoJoinTestCase(unittest.HomeserverTestCase):
         hs = self.setup_test_homeserver(room_member_handler=self.room_member_handler)
         return hs
 
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.handler = self.hs.get_registration_handler()
         self.store = self.hs.get_datastores().main
 
     @override_config({"auto_join_rooms": ["#room:remotetest"]})
-    def test_auto_create_auto_join_remote_room(self):
+    def test_auto_create_auto_join_remote_room(self) -> None:
         """Tests that we don't attempt to create remote rooms, and that we don't attempt
         to invite ourselves to rooms we're not in."""
 
diff --git a/tests/handlers/test_room.py b/tests/handlers/test_room.py
index fcde5dab72..df95490d3b 100644
--- a/tests/handlers/test_room.py
+++ b/tests/handlers/test_room.py
@@ -14,7 +14,7 @@ class EncryptedByDefaultTestCase(unittest.HomeserverTestCase):
     ]
 
     @override_config({"encryption_enabled_by_default_for_room_type": "all"})
-    def test_encrypted_by_default_config_option_all(self):
+    def test_encrypted_by_default_config_option_all(self) -> None:
         """Tests that invite-only and non-invite-only rooms have encryption enabled by
         default when the config option encryption_enabled_by_default_for_room_type is "all".
         """
@@ -45,7 +45,7 @@ class EncryptedByDefaultTestCase(unittest.HomeserverTestCase):
         self.assertEqual(event_content, {"algorithm": RoomEncryptionAlgorithms.DEFAULT})
 
     @override_config({"encryption_enabled_by_default_for_room_type": "invite"})
-    def test_encrypted_by_default_config_option_invite(self):
+    def test_encrypted_by_default_config_option_invite(self) -> None:
         """Tests that only new, invite-only rooms have encryption enabled by default when
         the config option encryption_enabled_by_default_for_room_type is "invite".
         """
@@ -76,7 +76,7 @@ class EncryptedByDefaultTestCase(unittest.HomeserverTestCase):
         )
 
     @override_config({"encryption_enabled_by_default_for_room_type": "off"})
-    def test_encrypted_by_default_config_option_off(self):
+    def test_encrypted_by_default_config_option_off(self) -> None:
         """Tests that neither new invite-only nor non-invite-only rooms have encryption
         enabled by default when the config option
         encryption_enabled_by_default_for_room_type is "off".
diff --git a/tests/handlers/test_room_summary.py b/tests/handlers/test_room_summary.py
index aa650756e4..d907fcaf04 100644
--- a/tests/handlers/test_room_summary.py
+++ b/tests/handlers/test_room_summary.py
@@ -11,10 +11,11 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
-from typing import Any, Iterable, List, Optional, Tuple
+from typing import Any, Dict, Iterable, List, Optional, Set, Tuple
 from unittest import mock
 
 from twisted.internet.defer import ensureDeferred
+from twisted.test.proto_helpers import MemoryReactor
 
 from synapse.api.constants import (
     EventContentFields,
@@ -34,11 +35,14 @@ from synapse.rest import admin
 from synapse.rest.client import login, room
 from synapse.server import HomeServer
 from synapse.types import JsonDict, UserID, create_requester
+from synapse.util import Clock
 
 from tests import unittest
 
 
-def _create_event(room_id: str, order: Optional[Any] = None, origin_server_ts: int = 0):
+def _create_event(
+    room_id: str, order: Optional[Any] = None, origin_server_ts: int = 0
+) -> mock.Mock:
     result = mock.Mock(name=room_id)
     result.room_id = room_id
     result.content = {}
@@ -48,40 +52,40 @@ def _create_event(room_id: str, order: Optional[Any] = None, origin_server_ts: i
     return result
 
 
-def _order(*events):
+def _order(*events: mock.Mock) -> List[mock.Mock]:
     return sorted(events, key=_child_events_comparison_key)
 
 
 class TestSpaceSummarySort(unittest.TestCase):
-    def test_no_order_last(self):
+    def test_no_order_last(self) -> None:
         """An event with no ordering is placed behind those with an ordering."""
         ev1 = _create_event("!abc:test")
         ev2 = _create_event("!xyz:test", "xyz")
 
         self.assertEqual([ev2, ev1], _order(ev1, ev2))
 
-    def test_order(self):
+    def test_order(self) -> None:
         """The ordering should be used."""
         ev1 = _create_event("!abc:test", "xyz")
         ev2 = _create_event("!xyz:test", "abc")
 
         self.assertEqual([ev2, ev1], _order(ev1, ev2))
 
-    def test_order_origin_server_ts(self):
+    def test_order_origin_server_ts(self) -> None:
         """Origin server  is a tie-breaker for ordering."""
         ev1 = _create_event("!abc:test", origin_server_ts=10)
         ev2 = _create_event("!xyz:test", origin_server_ts=30)
 
         self.assertEqual([ev1, ev2], _order(ev1, ev2))
 
-    def test_order_room_id(self):
+    def test_order_room_id(self) -> None:
         """Room ID is a final tie-breaker for ordering."""
         ev1 = _create_event("!abc:test")
         ev2 = _create_event("!xyz:test")
 
         self.assertEqual([ev1, ev2], _order(ev1, ev2))
 
-    def test_invalid_ordering_type(self):
+    def test_invalid_ordering_type(self) -> None:
         """Invalid orderings are considered the same as missing."""
         ev1 = _create_event("!abc:test", 1)
         ev2 = _create_event("!xyz:test", "xyz")
@@ -97,7 +101,7 @@ class TestSpaceSummarySort(unittest.TestCase):
         ev1 = _create_event("!abc:test", True)
         self.assertEqual([ev2, ev1], _order(ev1, ev2))
 
-    def test_invalid_ordering_value(self):
+    def test_invalid_ordering_value(self) -> None:
         """Invalid orderings are considered the same as missing."""
         ev1 = _create_event("!abc:test", "foo\n")
         ev2 = _create_event("!xyz:test", "xyz")
@@ -115,7 +119,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         login.register_servlets,
     ]
 
-    def prepare(self, reactor, clock, hs: HomeServer):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.hs = hs
         self.handler = self.hs.get_room_summary_handler()
 
@@ -223,7 +227,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             fed_handler.on_invite_request(fed_hostname, event, RoomVersions.V6)
         )
 
-    def test_simple_space(self):
+    def test_simple_space(self) -> None:
         """Test a simple space with a single room."""
         # The result should have the space and the room in it, along with a link
         # from space -> room.
@@ -234,7 +238,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         )
         self._assert_hierarchy(result, expected)
 
-    def test_large_space(self):
+    def test_large_space(self) -> None:
         """Test a space with a large number of rooms."""
         rooms = [self.room]
         # Make at least 51 rooms that are part of the space.
@@ -260,7 +264,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         result["rooms"] += result2["rooms"]
         self._assert_hierarchy(result, expected)
 
-    def test_visibility(self):
+    def test_visibility(self) -> None:
         """A user not in a space cannot inspect it."""
         user2 = self.register_user("user2", "pass")
         token2 = self.login("user2", "pass")
@@ -380,7 +384,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         self._assert_hierarchy(result2, [(self.space, [self.room])])
 
     def _create_room_with_join_rule(
-        self, join_rule: str, room_version: Optional[str] = None, **extra_content
+        self, join_rule: str, room_version: Optional[str] = None, **extra_content: Any
     ) -> str:
         """Create a room with the given join rule and add it to the space."""
         room_id = self.helper.create_room_as(
@@ -403,7 +407,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         self._add_child(self.space, room_id, self.token)
         return room_id
 
-    def test_filtering(self):
+    def test_filtering(self) -> None:
         """
         Rooms should be properly filtered to only include rooms the user has access to.
         """
@@ -476,7 +480,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         )
         self._assert_hierarchy(result, expected)
 
-    def test_complex_space(self):
+    def test_complex_space(self) -> None:
         """
         Create a "complex" space to see how it handles things like loops and subspaces.
         """
@@ -516,7 +520,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         )
         self._assert_hierarchy(result, expected)
 
-    def test_pagination(self):
+    def test_pagination(self) -> None:
         """Test simple pagination works."""
         room_ids = []
         for i in range(1, 10):
@@ -553,7 +557,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         self._assert_hierarchy(result, expected)
         self.assertNotIn("next_batch", result)
 
-    def test_invalid_pagination_token(self):
+    def test_invalid_pagination_token(self) -> None:
         """An invalid pagination token, or changing other parameters, shoudl be rejected."""
         room_ids = []
         for i in range(1, 10):
@@ -604,7 +608,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             SynapseError,
         )
 
-    def test_max_depth(self):
+    def test_max_depth(self) -> None:
         """Create a deep tree to test the max depth against."""
         spaces = [self.space]
         rooms = [self.room]
@@ -659,7 +663,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         ]
         self._assert_hierarchy(result, expected)
 
-    def test_unknown_room_version(self):
+    def test_unknown_room_version(self) -> None:
         """
         If a room with an unknown room version is encountered it should not cause
         the entire summary to skip.
@@ -685,7 +689,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
         )
         self._assert_hierarchy(result, expected)
 
-    def test_fed_complex(self):
+    def test_fed_complex(self) -> None:
         """
         Return data over federation and ensure that it is handled properly.
         """
@@ -722,7 +726,9 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             "world_readable": True,
         }
 
-        async def summarize_remote_room_hierarchy(_self, room, suggested_only):
+        async def summarize_remote_room_hierarchy(
+            _self: Any, room: Any, suggested_only: bool
+        ) -> Tuple[Optional[_RoomEntry], Dict[str, JsonDict], Set[str]]:
             return requested_room_entry, {subroom: child_room}, set()
 
         # Add a room to the space which is on another server.
@@ -744,7 +750,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             )
         self._assert_hierarchy(result, expected)
 
-    def test_fed_filtering(self):
+    def test_fed_filtering(self) -> None:
         """
         Rooms returned over federation should be properly filtered to only include
         rooms the user has access to.
@@ -853,7 +859,9 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             ],
         )
 
-        async def summarize_remote_room_hierarchy(_self, room, suggested_only):
+        async def summarize_remote_room_hierarchy(
+            _self: Any, room: Any, suggested_only: bool
+        ) -> Tuple[Optional[_RoomEntry], Dict[str, JsonDict], Set[str]]:
             return subspace_room_entry, dict(children_rooms), set()
 
         # Add a room to the space which is on another server.
@@ -892,7 +900,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             )
         self._assert_hierarchy(result, expected)
 
-    def test_fed_invited(self):
+    def test_fed_invited(self) -> None:
         """
         A room which the user was invited to should be included in the response.
 
@@ -915,7 +923,9 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             },
         )
 
-        async def summarize_remote_room_hierarchy(_self, room, suggested_only):
+        async def summarize_remote_room_hierarchy(
+            _self: Any, room: Any, suggested_only: bool
+        ) -> Tuple[Optional[_RoomEntry], Dict[str, JsonDict], Set[str]]:
             return fed_room_entry, {}, set()
 
         # Add a room to the space which is on another server.
@@ -936,7 +946,7 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase):
             )
         self._assert_hierarchy(result, expected)
 
-    def test_fed_caching(self):
+    def test_fed_caching(self) -> None:
         """
         Federation `/hierarchy` responses should be cached.
         """
@@ -1023,7 +1033,7 @@ class RoomSummaryTestCase(unittest.HomeserverTestCase):
         login.register_servlets,
     ]
 
-    def prepare(self, reactor, clock, hs: HomeServer):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.hs = hs
         self.handler = self.hs.get_room_summary_handler()
 
@@ -1040,12 +1050,12 @@ class RoomSummaryTestCase(unittest.HomeserverTestCase):
             tok=self.token,
         )
 
-    def test_own_room(self):
+    def test_own_room(self) -> None:
         """Test a simple room created by the requester."""
         result = self.get_success(self.handler.get_room_summary(self.user, self.room))
         self.assertEqual(result.get("room_id"), self.room)
 
-    def test_visibility(self):
+    def test_visibility(self) -> None:
         """A user not in a private room cannot get its summary."""
         user2 = self.register_user("user2", "pass")
         token2 = self.login("user2", "pass")
@@ -1093,7 +1103,7 @@ class RoomSummaryTestCase(unittest.HomeserverTestCase):
         result = self.get_success(self.handler.get_room_summary(user2, self.room))
         self.assertEqual(result.get("room_id"), self.room)
 
-    def test_fed(self):
+    def test_fed(self) -> None:
         """
         Return data over federation and ensure that it is handled properly.
         """
@@ -1105,7 +1115,9 @@ class RoomSummaryTestCase(unittest.HomeserverTestCase):
             {"room_id": fed_room, "world_readable": True},
         )
 
-        async def summarize_remote_room_hierarchy(_self, room, suggested_only):
+        async def summarize_remote_room_hierarchy(
+            _self: Any, room: Any, suggested_only: bool
+        ) -> Tuple[Optional[_RoomEntry], Dict[str, JsonDict], Set[str]]:
             return requested_room_entry, {}, set()
 
         with mock.patch(
diff --git a/tests/handlers/test_saml.py b/tests/handlers/test_saml.py
index a0f84e2940..9b1b8b9f13 100644
--- a/tests/handlers/test_saml.py
+++ b/tests/handlers/test_saml.py
@@ -12,7 +12,7 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-from typing import Any, Dict, Optional
+from typing import Any, Dict, Optional, Set, Tuple
 from unittest.mock import Mock
 
 import attr
@@ -20,7 +20,9 @@ import attr
 from twisted.test.proto_helpers import MemoryReactor
 
 from synapse.api.errors import RedirectException
+from synapse.module_api import ModuleApi
 from synapse.server import HomeServer
+from synapse.types import JsonDict
 from synapse.util import Clock
 
 from tests.test_utils import simple_async_mock
@@ -29,6 +31,7 @@ from tests.unittest import HomeserverTestCase, override_config
 # Check if we have the dependencies to run the tests.
 try:
     import saml2.config
+    import saml2.response
     from saml2.sigver import SigverError
 
     has_saml2 = True
@@ -56,31 +59,39 @@ class FakeAuthnResponse:
 
 
 class TestMappingProvider:
-    def __init__(self, config, module):
+    def __init__(self, config: None, module: ModuleApi):
         pass
 
     @staticmethod
-    def parse_config(config):
-        return
+    def parse_config(config: JsonDict) -> None:
+        return None
 
     @staticmethod
-    def get_saml_attributes(config):
+    def get_saml_attributes(config: None) -> Tuple[Set[str], Set[str]]:
         return {"uid"}, {"displayName"}
 
-    def get_remote_user_id(self, saml_response, client_redirect_url):
+    def get_remote_user_id(
+        self, saml_response: "saml2.response.AuthnResponse", client_redirect_url: str
+    ) -> str:
         return saml_response.ava["uid"]
 
     def saml_response_to_user_attributes(
-        self, saml_response, failures, client_redirect_url
-    ):
+        self,
+        saml_response: "saml2.response.AuthnResponse",
+        failures: int,
+        client_redirect_url: str,
+    ) -> dict:
         localpart = saml_response.ava["username"] + (str(failures) if failures else "")
         return {"mxid_localpart": localpart, "displayname": None}
 
 
 class TestRedirectMappingProvider(TestMappingProvider):
     def saml_response_to_user_attributes(
-        self, saml_response, failures, client_redirect_url
-    ):
+        self,
+        saml_response: "saml2.response.AuthnResponse",
+        failures: int,
+        client_redirect_url: str,
+    ) -> dict:
         raise RedirectException(b"https://custom-saml-redirect/")
 
 
@@ -347,7 +358,7 @@ class SamlHandlerTestCase(HomeserverTestCase):
         )
 
 
-def _mock_request():
+def _mock_request() -> Mock:
     """Returns a mock which will stand in as a SynapseRequest"""
     mock = Mock(
         spec=[
diff --git a/tests/handlers/test_send_email.py b/tests/handlers/test_send_email.py
index da4bf8b582..8b6e4a40b6 100644
--- a/tests/handlers/test_send_email.py
+++ b/tests/handlers/test_send_email.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 
-from typing import List, Tuple
+from typing import Callable, List, Tuple
 
 from zope.interface import implementer
 
@@ -28,20 +28,27 @@ from tests.unittest import HomeserverTestCase, override_config
 
 @implementer(interfaces.IMessageDelivery)
 class _DummyMessageDelivery:
-    def __init__(self):
+    def __init__(self) -> None:
         # (recipient, message) tuples
         self.messages: List[Tuple[smtp.Address, bytes]] = []
 
-    def receivedHeader(self, helo, origin, recipients):
+    def receivedHeader(
+        self,
+        helo: Tuple[bytes, bytes],
+        origin: smtp.Address,
+        recipients: List[smtp.User],
+    ) -> None:
         return None
 
-    def validateFrom(self, helo, origin):
+    def validateFrom(
+        self, helo: Tuple[bytes, bytes], origin: smtp.Address
+    ) -> smtp.Address:
         return origin
 
-    def record_message(self, recipient: smtp.Address, message: bytes):
+    def record_message(self, recipient: smtp.Address, message: bytes) -> None:
         self.messages.append((recipient, message))
 
-    def validateTo(self, user: smtp.User):
+    def validateTo(self, user: smtp.User) -> Callable[[], interfaces.IMessageSMTP]:
         return lambda: _DummyMessage(self, user)
 
 
@@ -56,20 +63,20 @@ class _DummyMessage:
         self._user = user
         self._buffer: List[bytes] = []
 
-    def lineReceived(self, line):
+    def lineReceived(self, line: bytes) -> None:
         self._buffer.append(line)
 
-    def eomReceived(self):
+    def eomReceived(self) -> "defer.Deferred[bytes]":
         message = b"\n".join(self._buffer) + b"\n"
         self._delivery.record_message(self._user.dest, message)
         return defer.succeed(b"saved")
 
-    def connectionLost(self):
+    def connectionLost(self) -> None:
         pass
 
 
 class SendEmailHandlerTestCase(HomeserverTestCase):
-    def test_send_email(self):
+    def test_send_email(self) -> None:
         """Happy-path test that we can send email to a non-TLS server."""
         h = self.hs.get_send_email_handler()
         d = ensureDeferred(
@@ -119,7 +126,7 @@ class SendEmailHandlerTestCase(HomeserverTestCase):
             },
         }
     )
-    def test_send_email_force_tls(self):
+    def test_send_email_force_tls(self) -> None:
         """Happy-path test that we can send email to an Implicit TLS server."""
         h = self.hs.get_send_email_handler()
         d = ensureDeferred(
diff --git a/tests/handlers/test_stats.py b/tests/handlers/test_stats.py
index 05f9ec3c51..f1a50c5bcb 100644
--- a/tests/handlers/test_stats.py
+++ b/tests/handlers/test_stats.py
@@ -12,9 +12,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any, Dict, List, Optional
+
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.rest import admin
 from synapse.rest.client import login, room
+from synapse.server import HomeServer
 from synapse.storage.databases.main import stats
+from synapse.util import Clock
 
 from tests import unittest
 
@@ -32,11 +38,11 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         login.register_servlets,
     ]
 
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.store = hs.get_datastores().main
         self.handler = self.hs.get_stats_handler()
 
-    def _add_background_updates(self):
+    def _add_background_updates(self) -> None:
         """
         Add the background updates we need to run.
         """
@@ -63,12 +69,14 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             )
         )
 
-    async def get_all_room_state(self):
+    async def get_all_room_state(self) -> List[Dict[str, Any]]:
         return await self.store.db_pool.simple_select_list(
             "room_stats_state", None, retcols=("name", "topic", "canonical_alias")
         )
 
-    def _get_current_stats(self, stats_type, stat_id):
+    def _get_current_stats(
+        self, stats_type: str, stat_id: str
+    ) -> Optional[Dict[str, Any]]:
         table, id_col = stats.TYPE_TO_TABLE[stats_type]
 
         cols = list(stats.ABSOLUTE_STATS_FIELDS[stats_type])
@@ -82,13 +90,13 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             )
         )
 
-    def _perform_background_initial_update(self):
+    def _perform_background_initial_update(self) -> None:
         # Do the initial population of the stats via the background update
         self._add_background_updates()
 
         self.wait_for_background_updates()
 
-    def test_initial_room(self):
+    def test_initial_room(self) -> None:
         """
         The background updates will build the table from scratch.
         """
@@ -125,7 +133,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.assertEqual(len(r), 1)
         self.assertEqual(r[0]["topic"], "foo")
 
-    def test_create_user(self):
+    def test_create_user(self) -> None:
         """
         When we create a user, it should have statistics already ready.
         """
@@ -134,12 +142,12 @@ class StatsRoomTests(unittest.HomeserverTestCase):
 
         u1stats = self._get_current_stats("user", u1)
 
-        self.assertIsNotNone(u1stats)
+        assert u1stats is not None
 
         # not in any rooms by default
         self.assertEqual(u1stats["joined_rooms"], 0)
 
-    def test_create_room(self):
+    def test_create_room(self) -> None:
         """
         When we create a room, it should have statistics already ready.
         """
@@ -153,8 +161,8 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         r2 = self.helper.create_room_as(u1, tok=u1token, is_public=False)
         r2stats = self._get_current_stats("room", r2)
 
-        self.assertIsNotNone(r1stats)
-        self.assertIsNotNone(r2stats)
+        assert r1stats is not None
+        assert r2stats is not None
 
         self.assertEqual(
             r1stats["current_state_events"], EXPT_NUM_STATE_EVTS_IN_FRESH_PUBLIC_ROOM
@@ -171,7 +179,9 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.assertEqual(r2stats["invited_members"], 0)
         self.assertEqual(r2stats["banned_members"], 0)
 
-    def test_updating_profile_information_does_not_increase_joined_members_count(self):
+    def test_updating_profile_information_does_not_increase_joined_members_count(
+        self,
+    ) -> None:
         """
         Check that the joined_members count does not increase when a user changes their
         profile information (which is done by sending another join membership event into
@@ -186,6 +196,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
 
         # Get the current room stats
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         # Send a profile update into the room
         new_profile = {"displayname": "bob"}
@@ -195,6 +206,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
 
         # Get the new room stats
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         # Ensure that the user count did not changed
         self.assertEqual(r1stats_post["joined_members"], r1stats_ante["joined_members"])
@@ -202,7 +214,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             r1stats_post["local_users_in_room"], r1stats_ante["local_users_in_room"]
         )
 
-    def test_send_state_event_nonoverwriting(self):
+    def test_send_state_event_nonoverwriting(self) -> None:
         """
         When we send a non-overwriting state event, it increments current_state_events
         """
@@ -218,19 +230,21 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         )
 
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         self.helper.send_state(
             r1, "cat.hissing", {"value": False}, tok=u1token, state_key="moggy"
         )
 
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         self.assertEqual(
             r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
             1,
         )
 
-    def test_join_first_time(self):
+    def test_join_first_time(self) -> None:
         """
         When a user joins a room for the first time, current_state_events and
         joined_members should increase by exactly 1.
@@ -246,10 +260,12 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         u2token = self.login("u2", "pass")
 
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         self.helper.join(r1, u2, tok=u2token)
 
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         self.assertEqual(
             r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
@@ -259,7 +275,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             r1stats_post["joined_members"] - r1stats_ante["joined_members"], 1
         )
 
-    def test_join_after_leave(self):
+    def test_join_after_leave(self) -> None:
         """
         When a user joins a room after being previously left,
         joined_members should increase by exactly 1.
@@ -280,10 +296,12 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.helper.leave(r1, u2, tok=u2token)
 
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         self.helper.join(r1, u2, tok=u2token)
 
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         self.assertEqual(
             r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
@@ -296,7 +314,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             r1stats_post["left_members"] - r1stats_ante["left_members"], -1
         )
 
-    def test_invited(self):
+    def test_invited(self) -> None:
         """
         When a user invites another user, current_state_events and
         invited_members should increase by exactly 1.
@@ -311,10 +329,12 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         u2 = self.register_user("u2", "pass")
 
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         self.helper.invite(r1, u1, u2, tok=u1token)
 
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         self.assertEqual(
             r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
@@ -324,7 +344,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             r1stats_post["invited_members"] - r1stats_ante["invited_members"], +1
         )
 
-    def test_join_after_invite(self):
+    def test_join_after_invite(self) -> None:
         """
         When a user joins a room after being invited and
         joined_members should increase by exactly 1.
@@ -344,10 +364,12 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.helper.invite(r1, u1, u2, tok=u1token)
 
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         self.helper.join(r1, u2, tok=u2token)
 
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         self.assertEqual(
             r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
@@ -360,7 +382,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             r1stats_post["invited_members"] - r1stats_ante["invited_members"], -1
         )
 
-    def test_left(self):
+    def test_left(self) -> None:
         """
         When a user leaves a room after joining and
         left_members should increase by exactly 1.
@@ -380,10 +402,12 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.helper.join(r1, u2, tok=u2token)
 
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         self.helper.leave(r1, u2, tok=u2token)
 
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         self.assertEqual(
             r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
@@ -396,7 +420,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             r1stats_post["joined_members"] - r1stats_ante["joined_members"], -1
         )
 
-    def test_banned(self):
+    def test_banned(self) -> None:
         """
         When a user is banned from a room after joining and
         left_members should increase by exactly 1.
@@ -416,10 +440,12 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.helper.join(r1, u2, tok=u2token)
 
         r1stats_ante = self._get_current_stats("room", r1)
+        assert r1stats_ante is not None
 
         self.helper.change_membership(r1, u1, u2, "ban", tok=u1token)
 
         r1stats_post = self._get_current_stats("room", r1)
+        assert r1stats_post is not None
 
         self.assertEqual(
             r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
@@ -432,7 +458,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             r1stats_post["joined_members"] - r1stats_ante["joined_members"], -1
         )
 
-    def test_initial_background_update(self):
+    def test_initial_background_update(self) -> None:
         """
         Test that statistics can be generated by the initial background update
         handler.
@@ -462,6 +488,9 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         r1stats = self._get_current_stats("room", r1)
         u1stats = self._get_current_stats("user", u1)
 
+        assert r1stats is not None
+        assert u1stats is not None
+
         self.assertEqual(r1stats["joined_members"], 1)
         self.assertEqual(
             r1stats["current_state_events"], EXPT_NUM_STATE_EVTS_IN_FRESH_PUBLIC_ROOM
@@ -469,7 +498,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
 
         self.assertEqual(u1stats["joined_rooms"], 1)
 
-    def test_incomplete_stats(self):
+    def test_incomplete_stats(self) -> None:
         """
         This tests that we track incomplete statistics.
 
@@ -533,8 +562,11 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.wait_for_background_updates()
 
         r1stats_complete = self._get_current_stats("room", r1)
+        assert r1stats_complete is not None
         u1stats_complete = self._get_current_stats("user", u1)
+        assert u1stats_complete is not None
         u2stats_complete = self._get_current_stats("user", u2)
+        assert u2stats_complete is not None
 
         # now we make our assertions
 
diff --git a/tests/handlers/test_sync.py b/tests/handlers/test_sync.py
index ab5c101eb7..0d9a3de92a 100644
--- a/tests/handlers/test_sync.py
+++ b/tests/handlers/test_sync.py
@@ -14,6 +14,8 @@
 from typing import Optional
 from unittest.mock import MagicMock, Mock, patch
 
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.constants import EventTypes, JoinRules
 from synapse.api.errors import Codes, ResourceLimitError
 from synapse.api.filtering import Filtering
@@ -23,6 +25,7 @@ from synapse.rest import admin
 from synapse.rest.client import knock, login, room
 from synapse.server import HomeServer
 from synapse.types import UserID, create_requester
+from synapse.util import Clock
 
 import tests.unittest
 import tests.utils
@@ -39,7 +42,7 @@ class SyncTestCase(tests.unittest.HomeserverTestCase):
         room.register_servlets,
     ]
 
-    def prepare(self, reactor, clock, hs: HomeServer):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.sync_handler = self.hs.get_sync_handler()
         self.store = self.hs.get_datastores().main
 
@@ -47,7 +50,7 @@ class SyncTestCase(tests.unittest.HomeserverTestCase):
         # modify its config instead of the hs'
         self.auth_blocking = self.hs.get_auth_blocking()
 
-    def test_wait_for_sync_for_user_auth_blocking(self):
+    def test_wait_for_sync_for_user_auth_blocking(self) -> None:
         user_id1 = "@user1:test"
         user_id2 = "@user2:test"
         sync_config = generate_sync_config(user_id1)
@@ -82,7 +85,7 @@ class SyncTestCase(tests.unittest.HomeserverTestCase):
         )
         self.assertEqual(e.value.errcode, Codes.RESOURCE_LIMIT_EXCEEDED)
 
-    def test_unknown_room_version(self):
+    def test_unknown_room_version(self) -> None:
         """
         A room with an unknown room version should not break sync (and should be excluded).
         """
@@ -186,7 +189,7 @@ class SyncTestCase(tests.unittest.HomeserverTestCase):
         self.assertNotIn(invite_room, [r.room_id for r in result.invited])
         self.assertNotIn(knock_room, [r.room_id for r in result.knocked])
 
-    def test_ban_wins_race_with_join(self):
+    def test_ban_wins_race_with_join(self) -> None:
         """Rooms shouldn't appear under "joined" if a join loses a race to a ban.
 
         A complicated edge case. Imagine the following scenario: