Ignore type assignments for mocked methods

mypy doesn't appear to have a better way to handle this.
python/mypy#2427

Convert method assignments to Mock usages were possible.

tests/handlers/test_typing.py

@@ -17,7 +17,6 @@
 from typing import Dict, List, Set, cast
 from unittest.mock import ANY, Mock, call
 
-from twisted.internet import defer
 from twisted.test.proto_helpers import MemoryReactor
 from twisted.web.resource import Resource
 
@@ -110,24 +109,24 @@ def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.event_source = hs.get_event_sources().sources.typing
 
         self.datastore = hs.get_datastores().main
+
         self.datastore.get_destination_retry_timings = Mock(
             return_value=make_awaitable(None)
         )
 
-        self.datastore.get_device_updates_by_remote = Mock(
+        self.datastore.get_device_updates_by_remote = Mock(  # type: ignore[assignment]
             return_value=make_awaitable((0, []))
         )
 
-        self.datastore.get_destination_last_successful_stream_ordering = Mock(
+        self.datastore.get_destination_last_successful_stream_ordering = Mock(  # type: ignore[assignment]
             return_value=make_awaitable(None)
         )
 
-        def get_received_txn_response(*args):
-            return defer.succeed(None)
-
-        self.datastore.get_received_txn_response = get_received_txn_response
+        self.datastore.get_received_txn_response = Mock(  # type: ignore[assignment]
+            return_value=make_awaitable(None)
+        )
 
-        self.room_members = []
+        self.room_members: List[UserID] = []
 
         async def check_user_in_room(room_id: str, requester: Requester) -> None:
             if requester.user.to_string() not in [
@@ -136,47 +135,54 @@ async def check_user_in_room(room_id: str, requester: Requester) -> None:
                 raise AuthError(401, "User is not in the room")
             return None
 
-        hs.get_auth().check_user_in_room = check_user_in_room
+        hs.get_auth().check_user_in_room = Mock(  # type: ignore[assignment]
+            side_effect=check_user_in_room
+        )
 
         async def check_host_in_room(room_id: str, server_name: str) -> bool:
             return room_id == ROOM_ID
 
-        hs.get_event_auth_handler().is_host_in_room = check_host_in_room
+        hs.get_event_auth_handler().is_host_in_room = Mock(  # type: ignore[assignment]
+            side_effect=check_host_in_room
+        )
 
-        async def get_current_hosts_in_room(room_id: str):
+        async def get_current_hosts_in_room(room_id: str) -> Set[str]:
             return {member.domain for member in self.room_members}
 
-        hs.get_storage_controllers().state.get_current_hosts_in_room = (
-            get_current_hosts_in_room
+        hs.get_storage_controllers().state.get_current_hosts_in_room = Mock(  # type: ignore[assignment]
+            side_effect=get_current_hosts_in_room
         )
 
-        hs.get_storage_controllers().state.get_current_hosts_in_room_or_partial_state_approximation = (
-            get_current_hosts_in_room
+        hs.get_storage_controllers().state.get_current_hosts_in_room_or_partial_state_approximation = Mock(  # type: ignore[assignment]
+            side_effect=get_current_hosts_in_room
         )
 
-        async def get_users_in_room(room_id: str):
+        async def get_users_in_room(room_id: str) -> Set[str]:
             return {str(u) for u in self.room_members}
 
-        self.datastore.get_users_in_room = get_users_in_room
+        self.datastore.get_users_in_room = Mock(side_effect=get_users_in_room)
 
-        self.datastore.get_user_directory_stream_pos = Mock(
+        self.datastore.get_user_directory_stream_pos = Mock(  # type: ignore[assignment]
             side_effect=(
-                # we deliberately return a non-None stream pos to avoid doing an initial_spam
+                # we deliberately return a non-None stream pos to avoid
+                # doing an initial_sync
                 lambda: make_awaitable(1)
             )
         )
 
-        self.datastore.get_partial_current_state_deltas = Mock(return_value=(0, None))
+        self.datastore.get_partial_current_state_deltas = Mock(return_value=(0, None))  # type: ignore[assignment]
 
-        self.datastore.get_to_device_stream_token = lambda: 0
-        self.datastore.get_new_device_msgs_for_remote = (
-            lambda *args, **kargs: make_awaitable(([], 0))
+        self.datastore.get_to_device_stream_token = Mock(  # type: ignore[assignment]
+            side_effect=lambda: 0
+        )
+        self.datastore.get_new_device_msgs_for_remote = Mock(  # type: ignore[assignment]
+            side_effect=lambda *args, **kargs: make_awaitable(([], 0))
         )
-        self.datastore.delete_device_msgs_for_remote = (
-            lambda *args, **kargs: make_awaitable(None)
+        self.datastore.delete_device_msgs_for_remote = Mock(  # type: ignore[assignment]
+            side_effect=lambda *args, **kargs: make_awaitable(None)
         )
-        self.datastore.set_received_txn_response = (
-            lambda *args, **kwargs: make_awaitable(None)
+        self.datastore.set_received_txn_response = Mock(  # type: ignore[assignment]
+            side_effect=lambda *args, **kwargs: make_awaitable(None)
         )
 
     def test_started_typing_local(self) -> None: