From e4903fbb96fa8aaa294d6092faaa9352ab8c37a2 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:16:36 -0500
Subject: [PATCH 01/13] Add missing type hints to test_mau and test_rust.

---
 mypy.ini           |  6 ------
 tests/test_mau.py  | 35 ++++++++++++++++++++++-------------
 tests/test_rust.py |  2 +-
 3 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index 1bdeb18d9496..6c9f659e36c1 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -78,12 +78,6 @@ disallow_untyped_defs = False
 [mypy-tests.test_federation]
 disallow_untyped_defs = False
 
-[mypy-tests.test_mau]
-disallow_untyped_defs = False
-
-[mypy-tests.test_rust]
-disallow_untyped_defs = False
-
 [mypy-tests.test_test_utils]
 disallow_untyped_defs = False
 
diff --git a/tests/test_mau.py b/tests/test_mau.py
index f14fcb7db9ba..4e7665a22b93 100644
--- a/tests/test_mau.py
+++ b/tests/test_mau.py
@@ -14,12 +14,17 @@
 
 """Tests REST events for /rooms paths."""
 
-from typing import List
+from typing import List, Optional
+
+from twisted.test.proto_helpers import MemoryReactor
 
 from synapse.api.constants import APP_SERVICE_REGISTRATION_TYPE, LoginType
 from synapse.api.errors import Codes, HttpResponseException, SynapseError
 from synapse.appservice import ApplicationService
 from synapse.rest.client import register, sync
+from synapse.server import HomeServer
+from synapse.types import JsonDict
+from synapse.util import Clock
 
 from tests import unittest
 from tests.unittest import override_config
@@ -30,7 +35,7 @@ class TestMauLimit(unittest.HomeserverTestCase):
 
     servlets = [register.register_servlets, sync.register_servlets]
 
-    def default_config(self):
+    def default_config(self) -> JsonDict:
         config = default_config("test")
 
         config.update(
@@ -53,10 +58,12 @@ def default_config(self):
 
         return config
 
-    def prepare(self, reactor, clock, homeserver):
+    def prepare(
+        self, reactor: MemoryReactor, clock: Clock, homeserver: HomeServer
+    ) -> None:
         self.store = homeserver.get_datastores().main
 
-    def test_simple_deny_mau(self):
+    def test_simple_deny_mau(self) -> None:
         # Create and sync so that the MAU counts get updated
         token1 = self.create_user("kermit1")
         self.do_sync_for_user(token1)
@@ -75,7 +82,7 @@ def test_simple_deny_mau(self):
         self.assertEqual(e.code, 403)
         self.assertEqual(e.errcode, Codes.RESOURCE_LIMIT_EXCEEDED)
 
-    def test_as_ignores_mau(self):
+    def test_as_ignores_mau(self) -> None:
         """Test that application services can still create users when the MAU
         limit has been reached. This only works when application service
         user ip tracking is disabled.
@@ -113,7 +120,7 @@ def test_as_ignores_mau(self):
 
         self.create_user("as_kermit4", token=as_token, appservice=True)
 
-    def test_allowed_after_a_month_mau(self):
+    def test_allowed_after_a_month_mau(self) -> None:
         # Create and sync so that the MAU counts get updated
         token1 = self.create_user("kermit1")
         self.do_sync_for_user(token1)
@@ -132,7 +139,7 @@ def test_allowed_after_a_month_mau(self):
         self.do_sync_for_user(token3)
 
     @override_config({"mau_trial_days": 1})
-    def test_trial_delay(self):
+    def test_trial_delay(self) -> None:
         # We should be able to register more than the limit initially
         token1 = self.create_user("kermit1")
         self.do_sync_for_user(token1)
@@ -165,7 +172,7 @@ def test_trial_delay(self):
         self.assertEqual(e.errcode, Codes.RESOURCE_LIMIT_EXCEEDED)
 
     @override_config({"mau_trial_days": 1})
-    def test_trial_users_cant_come_back(self):
+    def test_trial_users_cant_come_back(self) -> None:
         self.hs.config.server.mau_trial_days = 1
 
         # We should be able to register more than the limit initially
@@ -216,7 +223,7 @@ def test_trial_users_cant_come_back(self):
         # max_mau_value should not matter
         {"max_mau_value": 1, "limit_usage_by_mau": False, "mau_stats_only": True}
     )
-    def test_tracked_but_not_limited(self):
+    def test_tracked_but_not_limited(self) -> None:
         # Simply being able to create 2 users indicates that the
         # limit was not reached.
         token1 = self.create_user("kermit1")
@@ -236,10 +243,10 @@ def test_tracked_but_not_limited(self):
             "mau_appservice_trial_days": {"SomeASID": 1, "AnotherASID": 2},
         }
     )
-    def test_as_trial_days(self):
+    def test_as_trial_days(self) -> None:
         user_tokens: List[str] = []
 
-        def advance_time_and_sync():
+        def advance_time_and_sync() -> None:
             self.reactor.advance(24 * 60 * 61)
             for token in user_tokens:
                 self.do_sync_for_user(token)
@@ -300,7 +307,9 @@ def advance_time_and_sync():
             },
         )
 
-    def create_user(self, localpart, token=None, appservice=False):
+    def create_user(
+        self, localpart: str, token: Optional[str] = None, appservice: bool = False
+    ) -> str:
         request_data = {
             "username": localpart,
             "password": "monkey",
@@ -326,7 +335,7 @@ def create_user(self, localpart, token=None, appservice=False):
 
         return access_token
 
-    def do_sync_for_user(self, token):
+    def do_sync_for_user(self, token: str) -> None:
         channel = self.make_request("GET", "/sync", access_token=token)
 
         if channel.code != 200:
diff --git a/tests/test_rust.py b/tests/test_rust.py
index 55d8b6b28cb4..67443b628042 100644
--- a/tests/test_rust.py
+++ b/tests/test_rust.py
@@ -6,6 +6,6 @@
 class RustTestCase(unittest.TestCase):
     """Basic tests to ensure that we can call into Rust code."""
 
-    def test_basic(self):
+    def test_basic(self) -> None:
         result = sum_as_string(1, 2)
         self.assertEqual("3", result)

From 5bad3c72bfe1c53b1d05fbd3672cd85315e3ca05 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:19:56 -0500
Subject: [PATCH 02/13] Add missing type hints to test_test_utils and
 test_types..

---
 mypy.ini                 |  6 ------
 tests/test_test_utils.py | 16 ++++++++--------
 tests/test_types.py      | 30 +++++++++++++++---------------
 3 files changed, 23 insertions(+), 29 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index 6c9f659e36c1..679d4c07ce57 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -78,12 +78,6 @@ disallow_untyped_defs = False
 [mypy-tests.test_federation]
 disallow_untyped_defs = False
 
-[mypy-tests.test_test_utils]
-disallow_untyped_defs = False
-
-[mypy-tests.test_types]
-disallow_untyped_defs = False
-
 [mypy-tests.test_utils.*]
 disallow_untyped_defs = False
 
diff --git a/tests/test_test_utils.py b/tests/test_test_utils.py
index d04bcae0fabe..5cd698147e12 100644
--- a/tests/test_test_utils.py
+++ b/tests/test_test_utils.py
@@ -17,25 +17,25 @@
 
 
 class MockClockTestCase(unittest.TestCase):
-    def setUp(self):
+    def setUp(self) -> None:
         self.clock = MockClock()
 
-    def test_advance_time(self):
+    def test_advance_time(self) -> None:
         start_time = self.clock.time()
 
         self.clock.advance_time(20)
 
         self.assertEqual(20, self.clock.time() - start_time)
 
-    def test_later(self):
+    def test_later(self) -> None:
         invoked = [0, 0]
 
-        def _cb0():
+        def _cb0() -> None:
             invoked[0] = 1
 
         self.clock.call_later(10, _cb0)
 
-        def _cb1():
+        def _cb1() -> None:
             invoked[1] = 1
 
         self.clock.call_later(20, _cb1)
@@ -51,15 +51,15 @@ def _cb1():
 
         self.assertTrue(invoked[1])
 
-    def test_cancel_later(self):
+    def test_cancel_later(self) -> None:
         invoked = [0, 0]
 
-        def _cb0():
+        def _cb0() -> None:
             invoked[0] = 1
 
         t0 = self.clock.call_later(10, _cb0)
 
-        def _cb1():
+        def _cb1() -> None:
             invoked[1] = 1
 
         self.clock.call_later(20, _cb1)
diff --git a/tests/test_types.py b/tests/test_types.py
index 111116938423..c491cc9a9661 100644
--- a/tests/test_types.py
+++ b/tests/test_types.py
@@ -43,34 +43,34 @@ def test_two_colons(self) -> None:
 
 
 class UserIDTestCase(unittest.HomeserverTestCase):
-    def test_parse(self):
+    def test_parse(self) -> None:
         user = UserID.from_string("@1234abcd:test")
 
         self.assertEqual("1234abcd", user.localpart)
         self.assertEqual("test", user.domain)
         self.assertEqual(True, self.hs.is_mine(user))
 
-    def test_parse_rejects_empty_id(self):
+    def test_parse_rejects_empty_id(self) -> None:
         with self.assertRaises(SynapseError):
             UserID.from_string("")
 
-    def test_parse_rejects_missing_sigil(self):
+    def test_parse_rejects_missing_sigil(self) -> None:
         with self.assertRaises(SynapseError):
             UserID.from_string("alice:example.com")
 
-    def test_parse_rejects_missing_separator(self):
+    def test_parse_rejects_missing_separator(self) -> None:
         with self.assertRaises(SynapseError):
             UserID.from_string("@alice.example.com")
 
-    def test_validation_rejects_missing_domain(self):
+    def test_validation_rejects_missing_domain(self) -> None:
         self.assertFalse(UserID.is_valid("@alice:"))
 
-    def test_build(self):
+    def test_build(self) -> None:
         user = UserID("5678efgh", "my.domain")
 
         self.assertEqual(user.to_string(), "@5678efgh:my.domain")
 
-    def test_compare(self):
+    def test_compare(self) -> None:
         userA = UserID.from_string("@userA:my.domain")
         userAagain = UserID.from_string("@userA:my.domain")
         userB = UserID.from_string("@userB:my.domain")
@@ -80,43 +80,43 @@ def test_compare(self):
 
 
 class RoomAliasTestCase(unittest.HomeserverTestCase):
-    def test_parse(self):
+    def test_parse(self) -> None:
         room = RoomAlias.from_string("#channel:test")
 
         self.assertEqual("channel", room.localpart)
         self.assertEqual("test", room.domain)
         self.assertEqual(True, self.hs.is_mine(room))
 
-    def test_build(self):
+    def test_build(self) -> None:
         room = RoomAlias("channel", "my.domain")
 
         self.assertEqual(room.to_string(), "#channel:my.domain")
 
-    def test_validate(self):
+    def test_validate(self) -> None:
         id_string = "#test:domain,test"
         self.assertFalse(RoomAlias.is_valid(id_string))
 
 
 class MapUsernameTestCase(unittest.TestCase):
-    def testPassThrough(self):
+    def test_pass_througuh(self) -> None:
         self.assertEqual(map_username_to_mxid_localpart("test1234"), "test1234")
 
-    def testUpperCase(self):
+    def test_upper_case(self) -> None:
         self.assertEqual(map_username_to_mxid_localpart("tEST_1234"), "test_1234")
         self.assertEqual(
             map_username_to_mxid_localpart("tEST_1234", case_sensitive=True),
             "t_e_s_t__1234",
         )
 
-    def testSymbols(self):
+    def test_symbols(self) -> None:
         self.assertEqual(
             map_username_to_mxid_localpart("test=$?_1234"), "test=3d=24=3f_1234"
         )
 
-    def testLeadingUnderscore(self):
+    def test_leading_underscore(self) -> None:
         self.assertEqual(map_username_to_mxid_localpart("_test_1234"), "=5ftest_1234")
 
-    def testNonAscii(self):
+    def test_non_ascii(self) -> None:
         # this should work with either a unicode or a bytes
         self.assertEqual(map_username_to_mxid_localpart("têst"), "t=c3=aast")
         self.assertEqual(map_username_to_mxid_localpart("têst".encode()), "t=c3=aast")

From 6f49d7af6cadc0e8d16512da72a9bc9cb25cc8c4 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:21:38 -0500
Subject: [PATCH 03/13] Add type hints to test_distributor and test_event_auth.

---
 mypy.ini                  |  6 ------
 tests/test_distributor.py | 12 ++++++------
 tests/test_event_auth.py  | 32 +++++++++++++++++---------------
 3 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index 679d4c07ce57..70c106c668af 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -69,12 +69,6 @@ disallow_untyped_defs = False
 [mypy-tests.server_notices.test_resource_limits_server_notices]
 disallow_untyped_defs = False
 
-[mypy-tests.test_distributor]
-disallow_untyped_defs = False
-
-[mypy-tests.test_event_auth]
-disallow_untyped_defs = False
-
 [mypy-tests.test_federation]
 disallow_untyped_defs = False
 
diff --git a/tests/test_distributor.py b/tests/test_distributor.py
index 31546ea52bb0..a248f1d27711 100644
--- a/tests/test_distributor.py
+++ b/tests/test_distributor.py
@@ -21,10 +21,10 @@
 
 
 class DistributorTestCase(unittest.TestCase):
-    def setUp(self):
+    def setUp(self) -> None:
         self.dist = Distributor()
 
-    def test_signal_dispatch(self):
+    def test_signal_dispatch(self) -> None:
         self.dist.declare("alert")
 
         observer = Mock()
@@ -33,7 +33,7 @@ def test_signal_dispatch(self):
         self.dist.fire("alert", 1, 2, 3)
         observer.assert_called_with(1, 2, 3)
 
-    def test_signal_catch(self):
+    def test_signal_catch(self) -> None:
         self.dist.declare("alarm")
 
         observers = [Mock() for i in (1, 2)]
@@ -51,7 +51,7 @@ def test_signal_catch(self):
             self.assertEqual(mock_logger.warning.call_count, 1)
             self.assertIsInstance(mock_logger.warning.call_args[0][0], str)
 
-    def test_signal_prereg(self):
+    def test_signal_prereg(self) -> None:
         observer = Mock()
         self.dist.observe("flare", observer)
 
@@ -60,8 +60,8 @@ def test_signal_prereg(self):
 
         observer.assert_called_with(4, 5)
 
-    def test_signal_undeclared(self):
-        def code():
+    def test_signal_undeclared(self) -> None:
+        def code() -> None:
             self.dist.fire("notification")
 
         self.assertRaises(KeyError, code)
diff --git a/tests/test_event_auth.py b/tests/test_event_auth.py
index 0a7937f1cc72..2860564afc45 100644
--- a/tests/test_event_auth.py
+++ b/tests/test_event_auth.py
@@ -31,13 +31,13 @@
 class _StubEventSourceStore:
     """A stub implementation of the EventSourceStore"""
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._store: Dict[str, EventBase] = {}
 
-    def add_event(self, event: EventBase):
+    def add_event(self, event: EventBase) -> None:
         self._store[event.event_id] = event
 
-    def add_events(self, events: Iterable[EventBase]):
+    def add_events(self, events: Iterable[EventBase]) -> None:
         for event in events:
             self._store[event.event_id] = event
 
@@ -59,7 +59,7 @@ async def get_events(
 
 
 class EventAuthTestCase(unittest.TestCase):
-    def test_rejected_auth_events(self):
+    def test_rejected_auth_events(self) -> None:
         """
         Events that refer to rejected events in their auth events are rejected
         """
@@ -109,7 +109,7 @@ def test_rejected_auth_events(self):
                 )
             )
 
-    def test_create_event_with_prev_events(self):
+    def test_create_event_with_prev_events(self) -> None:
         """A create event with prev_events should be rejected
 
         https://spec.matrix.org/v1.3/rooms/v9/#authorization-rules
@@ -150,7 +150,7 @@ def test_create_event_with_prev_events(self):
                 event_auth.check_state_independent_auth_rules(event_store, bad_event)
             )
 
-    def test_duplicate_auth_events(self):
+    def test_duplicate_auth_events(self) -> None:
         """Events with duplicate auth_events should be rejected
 
         https://spec.matrix.org/v1.3/rooms/v9/#authorization-rules
@@ -196,7 +196,7 @@ def test_duplicate_auth_events(self):
                 event_auth.check_state_independent_auth_rules(event_store, bad_event2)
             )
 
-    def test_unexpected_auth_events(self):
+    def test_unexpected_auth_events(self) -> None:
         """Events with excess auth_events should be rejected
 
         https://spec.matrix.org/v1.3/rooms/v9/#authorization-rules
@@ -236,7 +236,7 @@ def test_unexpected_auth_events(self):
                 event_auth.check_state_independent_auth_rules(event_store, bad_event)
             )
 
-    def test_random_users_cannot_send_state_before_first_pl(self):
+    def test_random_users_cannot_send_state_before_first_pl(self) -> None:
         """
         Check that, before the first PL lands, the creator is the only user
         that can send a state event.
@@ -263,7 +263,7 @@ def test_random_users_cannot_send_state_before_first_pl(self):
             auth_events,
         )
 
-    def test_state_default_level(self):
+    def test_state_default_level(self) -> None:
         """
         Check that users above the state_default level can send state and
         those below cannot
@@ -298,7 +298,7 @@ def test_state_default_level(self):
             auth_events,
         )
 
-    def test_alias_event(self):
+    def test_alias_event(self) -> None:
         """Alias events have special behavior up through room version 6."""
         creator = "@creator:example.com"
         other = "@other:example.com"
@@ -333,7 +333,7 @@ def test_alias_event(self):
             auth_events,
         )
 
-    def test_msc2432_alias_event(self):
+    def test_msc2432_alias_event(self) -> None:
         """After MSC2432, alias events have no special behavior."""
         creator = "@creator:example.com"
         other = "@other:example.com"
@@ -366,7 +366,9 @@ def test_msc2432_alias_event(self):
             )
 
     @parameterized.expand([(RoomVersions.V1, True), (RoomVersions.V6, False)])
-    def test_notifications(self, room_version: RoomVersion, allow_modification: bool):
+    def test_notifications(
+        self, room_version: RoomVersion, allow_modification: bool
+    ) -> None:
         """
         Notifications power levels get checked due to MSC2209.
         """
@@ -395,7 +397,7 @@ def test_notifications(self, room_version: RoomVersion, allow_modification: bool
             with self.assertRaises(AuthError):
                 event_auth.check_state_dependent_auth_rules(pl_event, auth_events)
 
-    def test_join_rules_public(self):
+    def test_join_rules_public(self) -> None:
         """
         Test joining a public room.
         """
@@ -460,7 +462,7 @@ def test_join_rules_public(self):
             auth_events.values(),
         )
 
-    def test_join_rules_invite(self):
+    def test_join_rules_invite(self) -> None:
         """
         Test joining an invite only room.
         """
@@ -835,7 +837,7 @@ def _power_levels_event(
     )
 
 
-def _alias_event(room_version: RoomVersion, sender: str, **kwargs) -> EventBase:
+def _alias_event(room_version: RoomVersion, sender: str, **kwargs: Any) -> EventBase:
     data = {
         "room_id": TEST_ROOM_ID,
         **_maybe_get_event_id_dict_for_room_version(room_version),

From 871105089a72ea5e022859c53cb959694ad86cb1 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:26:51 -0500
Subject: [PATCH 04/13] Newsfragment

---
 changelog.d/15027.misc | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/15027.misc

diff --git a/changelog.d/15027.misc b/changelog.d/15027.misc
new file mode 100644
index 000000000000..93ceaeafc9b9
--- /dev/null
+++ b/changelog.d/15027.misc
@@ -0,0 +1 @@
+Improve type hints.

From ad38a8742168da02df0efd5aa2727c015d131117 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:35:01 -0500
Subject: [PATCH 05/13] Fix-up test_Federation.

---
 mypy.ini                 |  3 --
 tests/test_federation.py | 80 ++++++++++++++++++++++------------------
 2 files changed, 44 insertions(+), 39 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index 70c106c668af..941f26689010 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -69,9 +69,6 @@ disallow_untyped_defs = False
 [mypy-tests.server_notices.test_resource_limits_server_notices]
 disallow_untyped_defs = False
 
-[mypy-tests.test_federation]
-disallow_untyped_defs = False
-
 [mypy-tests.test_utils.*]
 disallow_untyped_defs = False
 
diff --git a/tests/test_federation.py b/tests/test_federation.py
index 80e5c590d836..ddb43c8c981a 100644
--- a/tests/test_federation.py
+++ b/tests/test_federation.py
@@ -12,53 +12,48 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Optional, Union
 from unittest.mock import Mock
 
 from twisted.internet.defer import succeed
+from twisted.test.proto_helpers import MemoryReactor
 
 from synapse.api.errors import FederationError
 from synapse.api.room_versions import RoomVersions
-from synapse.events import make_event_from_dict
+from synapse.events import EventBase, make_event_from_dict
+from synapse.events.snapshot import EventContext
 from synapse.federation.federation_base import event_from_pdu_json
+from synapse.http.types import QueryParams
 from synapse.logging.context import LoggingContext
-from synapse.types import UserID, create_requester
+from synapse.server import HomeServer
+from synapse.types import JsonDict, UserID, create_requester
 from synapse.util import Clock
 from synapse.util.retryutils import NotRetryingDestination
 
 from tests import unittest
-from tests.server import ThreadedMemoryReactorClock, setup_test_homeserver
 from tests.test_utils import make_awaitable
 
 
 class MessageAcceptTests(unittest.HomeserverTestCase):
-    def setUp(self):
-
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
         self.http_client = Mock()
-        self.reactor = ThreadedMemoryReactorClock()
-        self.hs_clock = Clock(self.reactor)
-        self.homeserver = setup_test_homeserver(
-            self.addCleanup,
-            federation_http_client=self.http_client,
-            clock=self.hs_clock,
-            reactor=self.reactor,
-        )
+        return self.setup_test_homeserver(federation_http_client=self.http_client)
 
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         user_id = UserID("us", "test")
         our_user = create_requester(user_id)
-        room_creator = self.homeserver.get_room_creation_handler()
+        room_creator = self.hs.get_room_creation_handler()
         self.room_id = self.get_success(
             room_creator.create_room(
                 our_user, room_creator._presets_dict["public_chat"], ratelimit=False
             )
         )[0]["room_id"]
 
-        self.store = self.homeserver.get_datastores().main
+        self.store = self.hs.get_datastores().main
 
         # Figure out what the most recent event is
         most_recent = self.get_success(
-            self.homeserver.get_datastores().main.get_latest_event_ids_in_room(
-                self.room_id
-            )
+            self.hs.get_datastores().main.get_latest_event_ids_in_room(self.room_id)
         )[0]
 
         join_event = make_event_from_dict(
@@ -78,14 +73,16 @@ def setUp(self):
             }
         )
 
-        self.handler = self.homeserver.get_federation_handler()
-        federation_event_handler = self.homeserver.get_federation_event_handler()
+        self.handler = self.hs.get_federation_handler()
+        federation_event_handler = self.hs.get_federation_event_handler()
 
-        async def _check_event_auth(origin, event, context):
+        async def _check_event_auth(
+            origin: Optional[str], event: EventBase, context: EventContext
+        ) -> None:
             pass
 
         federation_event_handler._check_event_auth = _check_event_auth
-        self.client = self.homeserver.get_federation_client()
+        self.client = self.hs.get_federation_client()
         self.client._check_sigs_and_hash_for_pulled_events_and_fetch = (
             lambda dest, pdus, **k: succeed(pdus)
         )
@@ -104,16 +101,25 @@ async def _check_event_auth(origin, event, context):
             "$join:test.serv",
         )
 
-    def test_cant_hide_direct_ancestors(self):
+    def test_cant_hide_direct_ancestors(self) -> None:
         """
         If you send a message, you must be able to provide the direct
         prev_events that said event references.
         """
 
-        async def post_json(destination, path, data, headers=None, timeout=0):
+        async def post_json(
+            destination: str,
+            path: str,
+            data: Optional[JsonDict] = None,
+            long_retries: bool = False,
+            timeout: Optional[int] = None,
+            ignore_backoff: bool = False,
+            args: Optional[QueryParams] = None,
+        ) -> Union[JsonDict, list]:
             # If it asks us for new missing events, give them NOTHING
             if path.startswith("/_matrix/federation/v1/get_missing_events/"):
                 return {"events": []}
+            return {}
 
         self.http_client.post_json = post_json
 
@@ -138,7 +144,7 @@ async def post_json(destination, path, data, headers=None, timeout=0):
             }
         )
 
-        federation_event_handler = self.homeserver.get_federation_event_handler()
+        federation_event_handler = self.hs.get_federation_event_handler()
         with LoggingContext("test-context"):
             failure = self.get_failure(
                 federation_event_handler.on_receive_pdu("test.serv", lying_event),
@@ -158,7 +164,7 @@ async def post_json(destination, path, data, headers=None, timeout=0):
         extrem = self.get_success(self.store.get_latest_event_ids_in_room(self.room_id))
         self.assertEqual(extrem[0], "$join:test.serv")
 
-    def test_retry_device_list_resync(self):
+    def test_retry_device_list_resync(self) -> None:
         """Tests that device lists are marked as stale if they couldn't be synced, and
         that stale device lists are retried periodically.
         """
@@ -171,24 +177,26 @@ def test_retry_device_list_resync(self):
         # When this function is called, increment the number of resync attempts (only if
         # we're querying devices for the right user ID), then raise a
         # NotRetryingDestination error to fail the resync gracefully.
-        def query_user_devices(destination, user_id):
+        def query_user_devices(
+            destination: str, user_id: str, timeout: int = 30000
+        ) -> JsonDict:
             if user_id == remote_user_id:
                 self.resync_attempts += 1
 
             raise NotRetryingDestination(0, 0, destination)
 
         # Register the mock on the federation client.
-        federation_client = self.homeserver.get_federation_client()
+        federation_client = self.hs.get_federation_client()
         federation_client.query_user_devices = Mock(side_effect=query_user_devices)
 
         # Register a mock on the store so that the incoming update doesn't fail because
         # we don't share a room with the user.
-        store = self.homeserver.get_datastores().main
+        store = self.hs.get_datastores().main
         store.get_rooms_for_user = Mock(return_value=make_awaitable(["!someroom:test"]))
 
         # Manually inject a fake device list update. We need this update to include at
         # least one prev_id so that the user's device list will need to be retried.
-        device_list_updater = self.homeserver.get_device_handler().device_list_updater
+        device_list_updater = self.hs.get_device_handler().device_list_updater
         self.get_success(
             device_list_updater.incoming_device_list_update(
                 origin=remote_origin,
@@ -218,7 +226,7 @@ def query_user_devices(destination, user_id):
         self.reactor.advance(30)
         self.assertEqual(self.resync_attempts, 2)
 
-    def test_cross_signing_keys_retry(self):
+    def test_cross_signing_keys_retry(self) -> None:
         """Tests that resyncing a device list correctly processes cross-signing keys from
         the remote server.
         """
@@ -227,7 +235,7 @@ def test_cross_signing_keys_retry(self):
         remote_self_signing_key = "QeIiFEjluPBtI7WQdG365QKZcFs9kqmHir6RBD0//nQ"
 
         # Register mock device list retrieval on the federation client.
-        federation_client = self.homeserver.get_federation_client()
+        federation_client = self.hs.get_federation_client()
         federation_client.query_user_devices = Mock(
             return_value=make_awaitable(
                 {
@@ -252,7 +260,7 @@ def test_cross_signing_keys_retry(self):
         )
 
         # Resync the device list.
-        device_handler = self.homeserver.get_device_handler()
+        device_handler = self.hs.get_device_handler()
         self.get_success(
             device_handler.device_list_updater.user_device_resync(remote_user_id),
         )
@@ -279,7 +287,7 @@ def test_cross_signing_keys_retry(self):
 
 
 class StripUnsignedFromEventsTestCase(unittest.TestCase):
-    def test_strip_unauthorized_unsigned_values(self):
+    def test_strip_unauthorized_unsigned_values(self) -> None:
         event1 = {
             "sender": "@baduser:test.serv",
             "state_key": "@baduser:test.serv",
@@ -296,7 +304,7 @@ def test_strip_unauthorized_unsigned_values(self):
         # Make sure unauthorized fields are stripped from unsigned
         self.assertNotIn("more warez", filtered_event.unsigned)
 
-    def test_strip_event_maintains_allowed_fields(self):
+    def test_strip_event_maintains_allowed_fields(self) -> None:
         event2 = {
             "sender": "@baduser:test.serv",
             "state_key": "@baduser:test.serv",
@@ -323,7 +331,7 @@ def test_strip_event_maintains_allowed_fields(self):
         self.assertIn("invite_room_state", filtered_event2.unsigned)
         self.assertEqual([], filtered_event2.unsigned["invite_room_state"])
 
-    def test_strip_event_removes_fields_based_on_event_type(self):
+    def test_strip_event_removes_fields_based_on_event_type(self) -> None:
         event3 = {
             "sender": "@baduser:test.serv",
             "state_key": "@baduser:test.serv",

From 75cb9deb44fa1c84de93d3d14d4385b236f318b9 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:35:58 -0500
Subject: [PATCH 06/13] Fix-up test_visibility.

---
 mypy.ini                 | 3 ---
 tests/test_visibility.py | 2 +-
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index 941f26689010..b260706e7ad2 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -72,9 +72,6 @@ disallow_untyped_defs = False
 [mypy-tests.test_utils.*]
 disallow_untyped_defs = False
 
-[mypy-tests.test_visibility]
-disallow_untyped_defs = False
-
 [mypy-tests.unittest]
 disallow_untyped_defs = False
 
diff --git a/tests/test_visibility.py b/tests/test_visibility.py
index d0b9ad54540d..875e37988f5d 100644
--- a/tests/test_visibility.py
+++ b/tests/test_visibility.py
@@ -258,7 +258,7 @@ def _inject_outlier(self) -> EventBase:
 
 
 class FilterEventsForClientTestCase(unittest.FederatingHomeserverTestCase):
-    def test_out_of_band_invite_rejection(self):
+    def test_out_of_band_invite_rejection(self) -> None:
         # this is where we have received an invite event over federation, and then
         # rejected it.
         invite_pdu = {

From 4908f0a97fe863b8d39a547dfebd1eef23d16d07 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:37:44 -0500
Subject: [PATCH 07/13] Partially fix tests.unittest.

---
 tests/unittest.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/unittest.py b/tests/unittest.py
index fa92dd94eb6a..68e59a88dc0f 100644
--- a/tests/unittest.py
+++ b/tests/unittest.py
@@ -315,7 +315,7 @@ def setUp(self) -> None:
 
                 # This has to be a function and not just a Mock, because
                 # `self.helper.auth_user_id` is temporarily reassigned in some tests
-                async def get_requester(*args, **kwargs) -> Requester:
+                async def get_requester(*args: Any, **kwargs: Any) -> Requester:
                     assert self.helper.auth_user_id is not None
                     return create_requester(
                         user_id=UserID.from_string(self.helper.auth_user_id),

From 84defca466aff84f072bb5d1665f0e1ef9ddb544 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 13:41:07 -0500
Subject: [PATCH 08/13] Handle tests.server_notices.

---
 mypy.ini                                      |  6 ----
 tests/server_notices/test_consent.py          | 14 ++++----
 .../test_resource_limits_server_notices.py    | 35 +++++++++++--------
 3 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index b260706e7ad2..52d0107366ef 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -63,12 +63,6 @@ disallow_untyped_defs = False
 [mypy-tests.scripts.test_new_matrix_user]
 disallow_untyped_defs = False
 
-[mypy-tests.server_notices.test_consent]
-disallow_untyped_defs = False
-
-[mypy-tests.server_notices.test_resource_limits_server_notices]
-disallow_untyped_defs = False
-
 [mypy-tests.test_utils.*]
 disallow_untyped_defs = False
 
diff --git a/tests/server_notices/test_consent.py b/tests/server_notices/test_consent.py
index 58b399a04377..6540ed53f173 100644
--- a/tests/server_notices/test_consent.py
+++ b/tests/server_notices/test_consent.py
@@ -14,8 +14,12 @@
 
 import os
 
+from twisted.test.proto_helpers import MemoryReactor
+
 import synapse.rest.admin
 from synapse.rest.client import login, room, sync
+from synapse.server import HomeServer
+from synapse.util import Clock
 
 from tests import unittest
 
@@ -29,7 +33,7 @@ class ConsentNoticesTests(unittest.HomeserverTestCase):
         room.register_servlets,
     ]
 
-    def make_homeserver(self, reactor, clock):
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
 
         tmpdir = self.mktemp()
         os.mkdir(tmpdir)
@@ -53,15 +57,13 @@ def make_homeserver(self, reactor, clock):
             "room_name": "Server Notices",
         }
 
-        hs = self.setup_test_homeserver(config=config)
-
-        return hs
+        return self.setup_test_homeserver(config=config)
 
-    def prepare(self, reactor, clock, hs):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.user_id = self.register_user("bob", "abc123")
         self.access_token = self.login("bob", "abc123")
 
-    def test_get_sync_message(self):
+    def test_get_sync_message(self) -> None:
         """
         When user consent server notices are enabled, a sync will cause a notice
         to fire (in a room which the user is invited to). The notice contains
diff --git a/tests/server_notices/test_resource_limits_server_notices.py b/tests/server_notices/test_resource_limits_server_notices.py
index dadc6efcbf75..5b76383d760a 100644
--- a/tests/server_notices/test_resource_limits_server_notices.py
+++ b/tests/server_notices/test_resource_limits_server_notices.py
@@ -24,6 +24,7 @@
 from synapse.server_notices.resource_limits_server_notices import (
     ResourceLimitsServerNotices,
 )
+from synapse.types import JsonDict
 from synapse.util import Clock
 
 from tests import unittest
@@ -33,7 +34,7 @@
 
 
 class TestResourceLimitsServerNotices(unittest.HomeserverTestCase):
-    def default_config(self):
+    def default_config(self) -> JsonDict:
         config = default_config("test")
 
         config.update(
@@ -86,18 +87,18 @@ def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self._rlsn._store.get_tags_for_room = Mock(return_value=make_awaitable({}))  # type: ignore[assignment]
 
     @override_config({"hs_disabled": True})
-    def test_maybe_send_server_notice_disabled_hs(self):
+    def test_maybe_send_server_notice_disabled_hs(self) -> None:
         """If the HS is disabled, we should not send notices"""
         self.get_success(self._rlsn.maybe_send_server_notice_to_user(self.user_id))
         self._send_notice.assert_not_called()
 
     @override_config({"limit_usage_by_mau": False})
-    def test_maybe_send_server_notice_to_user_flag_off(self):
+    def test_maybe_send_server_notice_to_user_flag_off(self) -> None:
         """If mau limiting is disabled, we should not send notices"""
         self.get_success(self._rlsn.maybe_send_server_notice_to_user(self.user_id))
         self._send_notice.assert_not_called()
 
-    def test_maybe_send_server_notice_to_user_remove_blocked_notice(self):
+    def test_maybe_send_server_notice_to_user_remove_blocked_notice(self) -> None:
         """Test when user has blocked notice, but should have it removed"""
 
         self._rlsn._auth_blocking.check_auth_blocking = Mock(
@@ -114,7 +115,7 @@ def test_maybe_send_server_notice_to_user_remove_blocked_notice(self):
         self._rlsn._server_notices_manager.maybe_get_notice_room_for_user.assert_called_once()
         self._send_notice.assert_called_once()
 
-    def test_maybe_send_server_notice_to_user_remove_blocked_notice_noop(self):
+    def test_maybe_send_server_notice_to_user_remove_blocked_notice_noop(self) -> None:
         """
         Test when user has blocked notice, but notice ought to be there (NOOP)
         """
@@ -134,7 +135,7 @@ def test_maybe_send_server_notice_to_user_remove_blocked_notice_noop(self):
 
         self._send_notice.assert_not_called()
 
-    def test_maybe_send_server_notice_to_user_add_blocked_notice(self):
+    def test_maybe_send_server_notice_to_user_add_blocked_notice(self) -> None:
         """
         Test when user does not have blocked notice, but should have one
         """
@@ -147,7 +148,7 @@ def test_maybe_send_server_notice_to_user_add_blocked_notice(self):
         # Would be better to check contents, but 2 calls == set blocking event
         self.assertEqual(self._send_notice.call_count, 2)
 
-    def test_maybe_send_server_notice_to_user_add_blocked_notice_noop(self):
+    def test_maybe_send_server_notice_to_user_add_blocked_notice_noop(self) -> None:
         """
         Test when user does not have blocked notice, nor should they (NOOP)
         """
@@ -159,7 +160,7 @@ def test_maybe_send_server_notice_to_user_add_blocked_notice_noop(self):
 
         self._send_notice.assert_not_called()
 
-    def test_maybe_send_server_notice_to_user_not_in_mau_cohort(self):
+    def test_maybe_send_server_notice_to_user_not_in_mau_cohort(self) -> None:
         """
         Test when user is not part of the MAU cohort - this should not ever
         happen - but ...
@@ -175,7 +176,9 @@ def test_maybe_send_server_notice_to_user_not_in_mau_cohort(self):
         self._send_notice.assert_not_called()
 
     @override_config({"mau_limit_alerting": False})
-    def test_maybe_send_server_notice_when_alerting_suppressed_room_unblocked(self):
+    def test_maybe_send_server_notice_when_alerting_suppressed_room_unblocked(
+        self,
+    ) -> None:
         """
         Test that when server is over MAU limit and alerting is suppressed, then
         an alert message is not sent into the room
@@ -191,7 +194,7 @@ def test_maybe_send_server_notice_when_alerting_suppressed_room_unblocked(self):
         self.assertEqual(self._send_notice.call_count, 0)
 
     @override_config({"mau_limit_alerting": False})
-    def test_check_hs_disabled_unaffected_by_mau_alert_suppression(self):
+    def test_check_hs_disabled_unaffected_by_mau_alert_suppression(self) -> None:
         """
         Test that when a server is disabled, that MAU limit alerting is ignored.
         """
@@ -207,7 +210,9 @@ def test_check_hs_disabled_unaffected_by_mau_alert_suppression(self):
         self.assertEqual(self._send_notice.call_count, 2)
 
     @override_config({"mau_limit_alerting": False})
-    def test_maybe_send_server_notice_when_alerting_suppressed_room_blocked(self):
+    def test_maybe_send_server_notice_when_alerting_suppressed_room_blocked(
+        self,
+    ) -> None:
         """
         When the room is already in a blocked state, test that when alerting
         is suppressed that the room is returned to an unblocked state.
@@ -242,7 +247,7 @@ class TestResourceLimitsServerNoticesWithRealRooms(unittest.HomeserverTestCase):
         sync.register_servlets,
     ]
 
-    def default_config(self):
+    def default_config(self) -> JsonDict:
         c = super().default_config()
         c["server_notices"] = {
             "system_mxid_localpart": "server",
@@ -270,7 +275,7 @@ def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
 
         self.user_id = "@user_id:test"
 
-    def test_server_notice_only_sent_once(self):
+    def test_server_notice_only_sent_once(self) -> None:
         self.store.get_monthly_active_count = Mock(return_value=make_awaitable(1000))
 
         self.store.user_last_seen_monthly_active = Mock(
@@ -306,7 +311,7 @@ def test_server_notice_only_sent_once(self):
 
         self.assertEqual(count, 1)
 
-    def test_no_invite_without_notice(self):
+    def test_no_invite_without_notice(self) -> None:
         """Tests that a user doesn't get invited to a server notices room without a
         server notice being sent.
 
@@ -328,7 +333,7 @@ def test_no_invite_without_notice(self):
 
         m.assert_called_once_with(user_id)
 
-    def test_invite_with_notice(self):
+    def test_invite_with_notice(self) -> None:
         """Tests that, if the MAU limit is hit, the server notices user invites each user
         to a room in which it has sent a notice.
         """

From b3773b97dffd87a2ffc28c698262dec87bef6322 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 14:05:08 -0500
Subject: [PATCH 09/13] Fix-up test_utils.

---
 mypy.ini                            |  3 ---
 tests/handlers/test_oidc.py         |  4 ++--
 tests/test_utils/__init__.py        | 23 ++++++++++++++---------
 tests/test_utils/event_injection.py |  8 ++++----
 tests/test_utils/html_parsers.py    |  6 +++---
 tests/test_utils/logging_setup.py   |  4 ++--
 tests/test_utils/oidc.py            | 10 +++++-----
 7 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index 52d0107366ef..dc6cfdb1810d 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -63,9 +63,6 @@ disallow_untyped_defs = False
 [mypy-tests.scripts.test_new_matrix_user]
 disallow_untyped_defs = False
 
-[mypy-tests.test_utils.*]
-disallow_untyped_defs = False
-
 [mypy-tests.unittest]
 disallow_untyped_defs = False
 
diff --git a/tests/handlers/test_oidc.py b/tests/handlers/test_oidc.py
index adddbd002f50..951caaa6b3ba 100644
--- a/tests/handlers/test_oidc.py
+++ b/tests/handlers/test_oidc.py
@@ -150,7 +150,7 @@ def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
 
         hs = self.setup_test_homeserver()
         self.hs_patcher = self.fake_server.patch_homeserver(hs=hs)
-        self.hs_patcher.start()
+        self.hs_patcher.start()  # type: ignore[attr-defined]
 
         self.handler = hs.get_oidc_handler()
         self.provider = self.handler._providers["oidc"]
@@ -170,7 +170,7 @@ def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
         return hs
 
     def tearDown(self) -> None:
-        self.hs_patcher.stop()
+        self.hs_patcher.stop()  # type: ignore[attr-defined]
         return super().tearDown()
 
     def reset_mocks(self) -> None:
diff --git a/tests/test_utils/__init__.py b/tests/test_utils/__init__.py
index e62ebcc6a5a3..e7b02ebd56bc 100644
--- a/tests/test_utils/__init__.py
+++ b/tests/test_utils/__init__.py
@@ -20,12 +20,13 @@
 import warnings
 from asyncio import Future
 from binascii import unhexlify
-from typing import Awaitable, Callable, Tuple, TypeVar
+from typing import Any, Awaitable, Callable, List, Optional, Tuple, TypeVar
 from unittest.mock import Mock
 
 import attr
 import zope.interface
 
+from twisted.internet.interfaces import IProtocol
 from twisted.python.failure import Failure
 from twisted.web.client import ResponseDone
 from twisted.web.http import RESPONSES
@@ -78,25 +79,29 @@ def setup_awaitable_errors() -> Callable[[], None]:
     unraisable_exceptions = []
     orig_unraisablehook = sys.unraisablehook
 
-    def unraisablehook(unraisable):
+    def unraisablehook(unraisable: sys.UnraisableHookArgs) -> None:
         unraisable_exceptions.append(unraisable.exc_value)
 
-    def cleanup():
+    def cleanup() -> None:
         """
         A method to be used as a clean-up that fails a test-case if there are any new unraisable exceptions.
         """
         sys.unraisablehook = orig_unraisablehook
         if unraisable_exceptions:
-            raise unraisable_exceptions.pop()
+            exc = unraisable_exceptions.pop()
+            assert exc is not None
+            raise exc
 
     sys.unraisablehook = unraisablehook
 
     return cleanup
 
 
-def simple_async_mock(return_value=None, raises=None) -> Mock:
+def simple_async_mock(
+    return_value: Optional[TV] = None, raises: Optional[Exception] = None
+) -> Mock:
     # AsyncMock is not available in python3.5, this mimics part of its behaviour
-    async def cb(*args, **kwargs):
+    async def cb(*args: Any, **kwargs: Any) -> Optional[TV]:
         if raises:
             raise raises
         return return_value
@@ -125,14 +130,14 @@ class FakeResponse:  # type: ignore[misc]
     headers: Headers = attr.Factory(Headers)
 
     @property
-    def phrase(self):
+    def phrase(self) -> bytes:
         return RESPONSES.get(self.code, b"Unknown Status")
 
     @property
-    def length(self):
+    def length(self) -> int:
         return len(self.body)
 
-    def deliverBody(self, protocol):
+    def deliverBody(self, protocol: IProtocol) -> None:
         protocol.dataReceived(self.body)
         protocol.connectionLost(Failure(ResponseDone()))
 
diff --git a/tests/test_utils/event_injection.py b/tests/test_utils/event_injection.py
index 8027c7a856e2..1a50c2acf12a 100644
--- a/tests/test_utils/event_injection.py
+++ b/tests/test_utils/event_injection.py
@@ -12,7 +12,7 @@
 # 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 List, Optional, Tuple
+from typing import Any, List, Optional, Tuple
 
 import synapse.server
 from synapse.api.constants import EventTypes
@@ -32,7 +32,7 @@ async def inject_member_event(
     membership: str,
     target: Optional[str] = None,
     extra_content: Optional[dict] = None,
-    **kwargs,
+    **kwargs: Any,
 ) -> EventBase:
     """Inject a membership event into a room."""
     if target is None:
@@ -57,7 +57,7 @@ async def inject_event(
     hs: synapse.server.HomeServer,
     room_version: Optional[str] = None,
     prev_event_ids: Optional[List[str]] = None,
-    **kwargs,
+    **kwargs: Any,
 ) -> EventBase:
     """Inject a generic event into a room
 
@@ -82,7 +82,7 @@ async def create_event(
     hs: synapse.server.HomeServer,
     room_version: Optional[str] = None,
     prev_event_ids: Optional[List[str]] = None,
-    **kwargs,
+    **kwargs: Any,
 ) -> Tuple[EventBase, EventContext]:
     if room_version is None:
         room_version = await hs.get_datastores().main.get_room_version_id(
diff --git a/tests/test_utils/html_parsers.py b/tests/test_utils/html_parsers.py
index e878af5f12e7..189c697efbee 100644
--- a/tests/test_utils/html_parsers.py
+++ b/tests/test_utils/html_parsers.py
@@ -13,13 +13,13 @@
 # limitations under the License.
 
 from html.parser import HTMLParser
-from typing import Dict, Iterable, List, Optional, Tuple
+from typing import Dict, Iterable, List, NoReturn, Optional, Tuple
 
 
 class TestHtmlParser(HTMLParser):
     """A generic HTML page parser which extracts useful things from the HTML"""
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
 
         # a list of links found in the doc
@@ -48,5 +48,5 @@ def handle_starttag(
                 assert input_name
                 self.hiddens[input_name] = attr_dict["value"]
 
-    def error(_, message):
+    def error(self, message: str) -> NoReturn:
         raise AssertionError(message)
diff --git a/tests/test_utils/logging_setup.py b/tests/test_utils/logging_setup.py
index 304c7b98c5c9..b522163a3444 100644
--- a/tests/test_utils/logging_setup.py
+++ b/tests/test_utils/logging_setup.py
@@ -25,7 +25,7 @@ class ToTwistedHandler(logging.Handler):
 
     tx_log = twisted.logger.Logger()
 
-    def emit(self, record):
+    def emit(self, record: logging.LogRecord) -> None:
         log_entry = self.format(record)
         log_level = record.levelname.lower().replace("warning", "warn")
         self.tx_log.emit(
@@ -33,7 +33,7 @@ def emit(self, record):
         )
 
 
-def setup_logging():
+def setup_logging() -> None:
     """Configure the python logging appropriately for the tests.
 
     (Logs will end up in _trial_temp.)
diff --git a/tests/test_utils/oidc.py b/tests/test_utils/oidc.py
index 1461d23ee823..d555b242555d 100644
--- a/tests/test_utils/oidc.py
+++ b/tests/test_utils/oidc.py
@@ -14,7 +14,7 @@
 
 
 import json
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, ContextManager, Dict, List, Optional, Tuple
 from unittest.mock import Mock, patch
 from urllib.parse import parse_qs
 
@@ -77,14 +77,14 @@ def __init__(self, clock: Clock, issuer: str):
 
         self._id_token_overrides: Dict[str, Any] = {}
 
-    def reset_mocks(self):
+    def reset_mocks(self) -> None:
         self.request.reset_mock()
         self.get_jwks_handler.reset_mock()
         self.get_metadata_handler.reset_mock()
         self.get_userinfo_handler.reset_mock()
         self.post_token_handler.reset_mock()
 
-    def patch_homeserver(self, hs: HomeServer):
+    def patch_homeserver(self, hs: HomeServer) -> ContextManager[Mock]:
         """Patch the ``HomeServer`` HTTP client to handle requests through the ``FakeOidcServer``.
 
         This patch should be used whenever the HS is expected to perform request to the
@@ -188,7 +188,7 @@ def generate_logout_token(self, grant: FakeAuthorizationGrant) -> str:
 
         return self._sign(logout_token)
 
-    def id_token_override(self, overrides: dict):
+    def id_token_override(self, overrides: dict) -> ContextManager[dict]:
         """Temporarily patch the ID token generated by the token endpoint."""
         return patch.object(self, "_id_token_overrides", overrides)
 
@@ -247,7 +247,7 @@ def buggy_endpoint(
         metadata: bool = False,
         token: bool = False,
         userinfo: bool = False,
-    ):
+    ) -> ContextManager[Dict[str, Mock]]:
         """A context which makes a set of endpoints return a 500 error.
 
         Args:

From 15f410a039a8355c76650f63458ba45456ecae49 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 14:13:35 -0500
Subject: [PATCH 10/13] Fix test_new_matrix_user.

---
 mypy.ini                              |  3 ---
 tests/scripts/test_new_matrix_user.py | 25 ++++++++++++++++---------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/mypy.ini b/mypy.ini
index dc6cfdb1810d..0e5c6ccf6121 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -60,9 +60,6 @@ disallow_untyped_defs = False
 [mypy-synapse.storage.database]
 disallow_untyped_defs = False
 
-[mypy-tests.scripts.test_new_matrix_user]
-disallow_untyped_defs = False
-
 [mypy-tests.unittest]
 disallow_untyped_defs = False
 
diff --git a/tests/scripts/test_new_matrix_user.py b/tests/scripts/test_new_matrix_user.py
index 22f99c6ab1ce..3285f2433ccf 100644
--- a/tests/scripts/test_new_matrix_user.py
+++ b/tests/scripts/test_new_matrix_user.py
@@ -12,29 +12,33 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
+from typing import List, Optional
 from unittest.mock import Mock, patch
 
 from synapse._scripts.register_new_matrix_user import request_registration
+from synapse.types import JsonDict
 
 from tests.unittest import TestCase
 
 
 class RegisterTestCase(TestCase):
-    def test_success(self):
+    def test_success(self) -> None:
         """
         The script will fetch a nonce, and then generate a MAC with it, and then
         post that MAC.
         """
 
-        def get(url, verify=None):
+        def get(url: str, verify: Optional[bool] = None) -> Mock:
             r = Mock()
             r.status_code = 200
             r.json = lambda: {"nonce": "a"}
             return r
 
-        def post(url, json=None, verify=None):
+        def post(
+            url: str, json: Optional[JsonDict] = None, verify: Optional[bool] = None
+        ) -> Mock:
             # Make sure we are sent the correct info
+            assert json is not None
             self.assertEqual(json["username"], "user")
             self.assertEqual(json["password"], "pass")
             self.assertEqual(json["nonce"], "a")
@@ -70,12 +74,12 @@ def post(url, json=None, verify=None):
         # sys.exit shouldn't have been called.
         self.assertEqual(err_code, [])
 
-    def test_failure_nonce(self):
+    def test_failure_nonce(self) -> None:
         """
         If the script fails to fetch a nonce, it throws an error and quits.
         """
 
-        def get(url, verify=None):
+        def get(url: str, verify: Optional[bool] = None) -> Mock:
             r = Mock()
             r.status_code = 404
             r.reason = "Not Found"
@@ -107,20 +111,23 @@ def get(url, verify=None):
         self.assertIn("ERROR! Received 404 Not Found", out)
         self.assertNotIn("Success!", out)
 
-    def test_failure_post(self):
+    def test_failure_post(self) -> None:
         """
         The script will fetch a nonce, and then if the final POST fails, will
         report an error and quit.
         """
 
-        def get(url, verify=None):
+        def get(url: str, verify: Optional[bool] = None) -> Mock:
             r = Mock()
             r.status_code = 200
             r.json = lambda: {"nonce": "a"}
             return r
 
-        def post(url, json=None, verify=None):
+        def post(
+            url: str, json: Optional[JsonDict] = None, verify: Optional[bool] = None
+        ) -> Mock:
             # Make sure we are sent the correct info
+            assert json is not None
             self.assertEqual(json["username"], "user")
             self.assertEqual(json["password"], "pass")
             self.assertEqual(json["nonce"], "a")

From 65906dd07a359bbd3250dd6b793f4ea624b396cf Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 14:15:51 -0500
Subject: [PATCH 11/13] Newsfragment

---
 changelog.d/15028.misc | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/15028.misc

diff --git a/changelog.d/15028.misc b/changelog.d/15028.misc
new file mode 100644
index 000000000000..93ceaeafc9b9
--- /dev/null
+++ b/changelog.d/15028.misc
@@ -0,0 +1 @@
+Improve type hints.

From 9a848cff8c0dec97ac67bb5bb53e34513925b9dc Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 14:24:26 -0500
Subject: [PATCH 12/13] Unused import.

---
 tests/test_utils/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_utils/__init__.py b/tests/test_utils/__init__.py
index e7b02ebd56bc..d3fcb7144797 100644
--- a/tests/test_utils/__init__.py
+++ b/tests/test_utils/__init__.py
@@ -20,7 +20,7 @@
 import warnings
 from asyncio import Future
 from binascii import unhexlify
-from typing import Any, Awaitable, Callable, List, Optional, Tuple, TypeVar
+from typing import Any, Awaitable, Callable, Optional, Tuple, TypeVar
 from unittest.mock import Mock
 
 import attr

From ea95563c289bfe80402f574f061e5bb5110ddd3f Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Wed, 8 Feb 2023 14:57:23 -0500
Subject: [PATCH 13/13] Fix-up import.

---
 tests/test_utils/__init__.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tests/test_utils/__init__.py b/tests/test_utils/__init__.py
index d3fcb7144797..e5dae670a70e 100644
--- a/tests/test_utils/__init__.py
+++ b/tests/test_utils/__init__.py
@@ -20,7 +20,7 @@
 import warnings
 from asyncio import Future
 from binascii import unhexlify
-from typing import Any, Awaitable, Callable, Optional, Tuple, TypeVar
+from typing import TYPE_CHECKING, Any, Awaitable, Callable, Optional, Tuple, TypeVar
 from unittest.mock import Mock
 
 import attr
@@ -35,6 +35,9 @@
 
 from synapse.types import JsonDict
 
+if TYPE_CHECKING:
+    from sys import UnraisableHookArgs
+
 TV = TypeVar("TV")
 
 
@@ -79,7 +82,7 @@ def setup_awaitable_errors() -> Callable[[], None]:
     unraisable_exceptions = []
     orig_unraisablehook = sys.unraisablehook
 
-    def unraisablehook(unraisable: sys.UnraisableHookArgs) -> None:
+    def unraisablehook(unraisable: "UnraisableHookArgs") -> None:
         unraisable_exceptions.append(unraisable.exc_value)
 
     def cleanup() -> None: