Allow for make_awaitable's return value to be re-used. (#8261)

12 files changed, 56 insertions, 70 deletions

diff --git a/changelog.d/8261.misc b/changelog.d/8261.misc
new file mode 100644
index 0000000000..bc91e9375c
--- /dev/null
+++ b/changelog.d/8261.misc
@@ -0,0 +1 @@
+Simplify tests that mock asynchronous functions.
diff --git a/tests/federation/test_complexity.py b/tests/federation/test_complexity.py
index 3d880c499d..1471cc1a28 100644
--- a/tests/federation/test_complexity.py
+++ b/tests/federation/test_complexity.py
@@ -77,11 +77,9 @@ class RoomComplexityTests(unittest.FederatingHomeserverTestCase):
         fed_transport = self.hs.get_federation_transport_client()
 
         # Mock out some things, because we don't want to test the whole join
-        fed_transport.client.get_json = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable({"v1": 9999})
-        )
+        fed_transport.client.get_json = Mock(return_value=make_awaitable({"v1": 9999}))
         handler.federation_handler.do_invite_join = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable(("", 1))
+            return_value=make_awaitable(("", 1))
         )
 
         d = handler._remote_join(
@@ -110,11 +108,9 @@ class RoomComplexityTests(unittest.FederatingHomeserverTestCase):
         fed_transport = self.hs.get_federation_transport_client()
 
         # Mock out some things, because we don't want to test the whole join
-        fed_transport.client.get_json = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable({"v1": 9999})
-        )
+        fed_transport.client.get_json = Mock(return_value=make_awaitable({"v1": 9999}))
         handler.federation_handler.do_invite_join = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable(("", 1))
+            return_value=make_awaitable(("", 1))
         )
 
         d = handler._remote_join(
@@ -150,11 +146,9 @@ class RoomComplexityTests(unittest.FederatingHomeserverTestCase):
         fed_transport = self.hs.get_federation_transport_client()
 
         # Mock out some things, because we don't want to test the whole join
-        fed_transport.client.get_json = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable(None)
-        )
+        fed_transport.client.get_json = Mock(return_value=make_awaitable(None))
         handler.federation_handler.do_invite_join = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable(("", 1))
+            return_value=make_awaitable(("", 1))
         )
 
         # Artificially raise the complexity
@@ -208,11 +202,9 @@ class RoomComplexityAdminTests(unittest.FederatingHomeserverTestCase):
         fed_transport = self.hs.get_federation_transport_client()
 
         # Mock out some things, because we don't want to test the whole join
-        fed_transport.client.get_json = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable({"v1": 9999})
-        )
+        fed_transport.client.get_json = Mock(return_value=make_awaitable({"v1": 9999}))
         handler.federation_handler.do_invite_join = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable(("", 1))
+            return_value=make_awaitable(("", 1))
         )
 
         d = handler._remote_join(
@@ -240,11 +232,9 @@ class RoomComplexityAdminTests(unittest.FederatingHomeserverTestCase):
         fed_transport = self.hs.get_federation_transport_client()
 
         # Mock out some things, because we don't want to test the whole join
-        fed_transport.client.get_json = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable({"v1": 9999})
-        )
+        fed_transport.client.get_json = Mock(return_value=make_awaitable({"v1": 9999}))
         handler.federation_handler.do_invite_join = Mock(
-            side_effect=lambda *args, **kwargs: make_awaitable(("", 1))
+            return_value=make_awaitable(("", 1))
         )
 
         d = handler._remote_join(
diff --git a/tests/federation/test_federation_sender.py b/tests/federation/test_federation_sender.py
index 5f512ff8bf..917762e6b6 100644
--- a/tests/federation/test_federation_sender.py
+++ b/tests/federation/test_federation_sender.py
@@ -34,7 +34,7 @@ class FederationSenderReceiptsTestCases(HomeserverTestCase):
     def make_homeserver(self, reactor, clock):
         mock_state_handler = Mock(spec=["get_current_hosts_in_room"])
         # Ensure a new Awaitable is created for each call.
-        mock_state_handler.get_current_hosts_in_room.side_effect = lambda room_Id: make_awaitable(
+        mock_state_handler.get_current_hosts_in_room.return_value = make_awaitable(
             ["test", "host2"]
         )
         return self.setup_test_homeserver(
diff --git a/tests/handlers/test_auth.py b/tests/handlers/test_auth.py
index c7efd3822d..97877c2e42 100644
--- a/tests/handlers/test_auth.py
+++ b/tests/handlers/test_auth.py
@@ -143,7 +143,7 @@ class AuthTestCase(unittest.TestCase):
     def test_mau_limits_exceeded_large(self):
         self.auth_blocking._limit_usage_by_mau = True
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.large_number_of_users)
+            return_value=make_awaitable(self.large_number_of_users)
         )
 
         with self.assertRaises(ResourceLimitError):
@@ -154,7 +154,7 @@ class AuthTestCase(unittest.TestCase):
             )
 
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.large_number_of_users)
+            return_value=make_awaitable(self.large_number_of_users)
         )
         with self.assertRaises(ResourceLimitError):
             yield defer.ensureDeferred(
@@ -169,7 +169,7 @@ class AuthTestCase(unittest.TestCase):
 
         # If not in monthly active cohort
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.auth_blocking._max_mau_value)
+            return_value=make_awaitable(self.auth_blocking._max_mau_value)
         )
         with self.assertRaises(ResourceLimitError):
             yield defer.ensureDeferred(
@@ -179,7 +179,7 @@ class AuthTestCase(unittest.TestCase):
             )
 
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.auth_blocking._max_mau_value)
+            return_value=make_awaitable(self.auth_blocking._max_mau_value)
         )
         with self.assertRaises(ResourceLimitError):
             yield defer.ensureDeferred(
@@ -189,10 +189,10 @@ class AuthTestCase(unittest.TestCase):
             )
         # If in monthly active cohort
         self.hs.get_datastore().user_last_seen_monthly_active = Mock(
-            side_effect=lambda user_id: make_awaitable(self.hs.get_clock().time_msec())
+            return_value=make_awaitable(self.hs.get_clock().time_msec())
         )
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.auth_blocking._max_mau_value)
+            return_value=make_awaitable(self.auth_blocking._max_mau_value)
         )
         yield defer.ensureDeferred(
             self.auth_handler.get_access_token_for_user_id(
@@ -200,10 +200,10 @@ class AuthTestCase(unittest.TestCase):
             )
         )
         self.hs.get_datastore().user_last_seen_monthly_active = Mock(
-            side_effect=lambda user_id: make_awaitable(self.hs.get_clock().time_msec())
+            return_value=make_awaitable(self.hs.get_clock().time_msec())
         )
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.auth_blocking._max_mau_value)
+            return_value=make_awaitable(self.auth_blocking._max_mau_value)
         )
         yield defer.ensureDeferred(
             self.auth_handler.validate_short_term_login_token_and_get_user_id(
@@ -216,7 +216,7 @@ class AuthTestCase(unittest.TestCase):
         self.auth_blocking._limit_usage_by_mau = True
 
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.small_number_of_users)
+            return_value=make_awaitable(self.small_number_of_users)
         )
         # Ensure does not raise exception
         yield defer.ensureDeferred(
@@ -226,7 +226,7 @@ class AuthTestCase(unittest.TestCase):
         )
 
         self.hs.get_datastore().get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.small_number_of_users)
+            return_value=make_awaitable(self.small_number_of_users)
         )
         yield defer.ensureDeferred(
             self.auth_handler.validate_short_term_login_token_and_get_user_id(
diff --git a/tests/handlers/test_register.py b/tests/handlers/test_register.py
index eddf5e2498..cb7c0ed51a 100644
--- a/tests/handlers/test_register.py
+++ b/tests/handlers/test_register.py
@@ -100,7 +100,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
     def test_get_or_create_user_mau_not_blocked(self):
         self.hs.config.limit_usage_by_mau = True
         self.store.count_monthly_users = Mock(
-            side_effect=lambda: make_awaitable(self.hs.config.max_mau_value - 1)
+            return_value=make_awaitable(self.hs.config.max_mau_value - 1)
         )
         # Ensure does not throw exception
         self.get_success(self.get_or_create_user(self.requester, "c", "User"))
@@ -108,7 +108,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
     def test_get_or_create_user_mau_blocked(self):
         self.hs.config.limit_usage_by_mau = True
         self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.lots_of_users)
+            return_value=make_awaitable(self.lots_of_users)
         )
         self.get_failure(
             self.get_or_create_user(self.requester, "b", "display_name"),
@@ -116,7 +116,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         )
 
         self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.hs.config.max_mau_value)
+            return_value=make_awaitable(self.hs.config.max_mau_value)
         )
         self.get_failure(
             self.get_or_create_user(self.requester, "b", "display_name"),
@@ -126,14 +126,14 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
     def test_register_mau_blocked(self):
         self.hs.config.limit_usage_by_mau = True
         self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.lots_of_users)
+            return_value=make_awaitable(self.lots_of_users)
         )
         self.get_failure(
             self.handler.register_user(localpart="local_part"), ResourceLimitError
         )
 
         self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.hs.config.max_mau_value)
+            return_value=make_awaitable(self.hs.config.max_mau_value)
         )
         self.get_failure(
             self.handler.register_user(localpart="local_part"), ResourceLimitError
diff --git a/tests/handlers/test_typing.py b/tests/handlers/test_typing.py
index 7bf15c4ba9..ae6bc24f4c 100644
--- a/tests/handlers/test_typing.py
+++ b/tests/handlers/test_typing.py
@@ -116,7 +116,7 @@ class TypingNotificationsTestCase(unittest.HomeserverTestCase):
             retry_timings_res
         )
 
-        self.datastore.get_device_updates_by_remote.side_effect = lambda destination, from_stream_id, limit: make_awaitable(
+        self.datastore.get_device_updates_by_remote.return_value = make_awaitable(
             (0, [])
         )
 
diff --git a/tests/replication/test_federation_sender_shard.py b/tests/replication/test_federation_sender_shard.py
index 8b4982ecb1..1d7edee5ba 100644
--- a/tests/replication/test_federation_sender_shard.py
+++ b/tests/replication/test_federation_sender_shard.py
@@ -45,7 +45,7 @@ class FederationSenderTestCase(BaseMultiWorkerStreamTestCase):
         new event.
         """
         mock_client = Mock(spec=["put_json"])
-        mock_client.put_json.side_effect = lambda *_, **__: make_awaitable({})
+        mock_client.put_json.return_value = make_awaitable({})
 
         self.make_worker_hs(
             "synapse.app.federation_sender",
@@ -73,7 +73,7 @@ class FederationSenderTestCase(BaseMultiWorkerStreamTestCase):
         new events.
         """
         mock_client1 = Mock(spec=["put_json"])
-        mock_client1.put_json.side_effect = lambda *_, **__: make_awaitable({})
+        mock_client1.put_json.return_value = make_awaitable({})
         self.make_worker_hs(
             "synapse.app.federation_sender",
             {
@@ -85,7 +85,7 @@ class FederationSenderTestCase(BaseMultiWorkerStreamTestCase):
         )
 
         mock_client2 = Mock(spec=["put_json"])
-        mock_client2.put_json.side_effect = lambda *_, **__: make_awaitable({})
+        mock_client2.put_json.return_value = make_awaitable({})
         self.make_worker_hs(
             "synapse.app.federation_sender",
             {
@@ -136,7 +136,7 @@ class FederationSenderTestCase(BaseMultiWorkerStreamTestCase):
         new typing EDUs.
         """
         mock_client1 = Mock(spec=["put_json"])
-        mock_client1.put_json.side_effect = lambda *_, **__: make_awaitable({})
+        mock_client1.put_json.return_value = make_awaitable({})
         self.make_worker_hs(
             "synapse.app.federation_sender",
             {
@@ -148,7 +148,7 @@ class FederationSenderTestCase(BaseMultiWorkerStreamTestCase):
         )
 
         mock_client2 = Mock(spec=["put_json"])
-        mock_client2.put_json.side_effect = lambda *_, **__: make_awaitable({})
+        mock_client2.put_json.return_value = make_awaitable({})
         self.make_worker_hs(
             "synapse.app.federation_sender",
             {
diff --git a/tests/rest/admin/test_user.py b/tests/rest/admin/test_user.py
index 160c630235..b8b7758d24 100644
--- a/tests/rest/admin/test_user.py
+++ b/tests/rest/admin/test_user.py
@@ -337,7 +337,7 @@ class UserRegisterTestCase(unittest.HomeserverTestCase):
 
         # Set monthly active users to the limit
         store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.hs.config.max_mau_value)
+            return_value=make_awaitable(self.hs.config.max_mau_value)
         )
         # Check that the blocking of monthly active users is working as expected
         # The registration of a new user fails due to the limit
@@ -591,7 +591,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
 
         # Set monthly active users to the limit
         self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.hs.config.max_mau_value)
+            return_value=make_awaitable(self.hs.config.max_mau_value)
         )
         # Check that the blocking of monthly active users is working as expected
         # The registration of a new user fails due to the limit
@@ -631,7 +631,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
 
         # Set monthly active users to the limit
         self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(self.hs.config.max_mau_value)
+            return_value=make_awaitable(self.hs.config.max_mau_value)
         )
         # Check that the blocking of monthly active users is working as expected
         # The registration of a new user fails due to the limit
diff --git a/tests/server_notices/test_resource_limits_server_notices.py b/tests/server_notices/test_resource_limits_server_notices.py
index 973338ea71..6382b19dc3 100644
--- a/tests/server_notices/test_resource_limits_server_notices.py
+++ b/tests/server_notices/test_resource_limits_server_notices.py
@@ -67,7 +67,7 @@ class TestResourceLimitsServerNotices(unittest.HomeserverTestCase):
             raise Exception("Failed to find reference to ResourceLimitsServerNotices")
 
         self._rlsn._store.user_last_seen_monthly_active = Mock(
-            side_effect=lambda user_id: make_awaitable(1000)
+            return_value=make_awaitable(1000)
         )
         self._rlsn._server_notices_manager.send_notice = Mock(
             return_value=defer.succeed(Mock())
@@ -80,9 +80,7 @@ class TestResourceLimitsServerNotices(unittest.HomeserverTestCase):
             return_value=defer.succeed("!something:localhost")
         )
         self._rlsn._store.add_tag_to_room = Mock(return_value=defer.succeed(None))
-        self._rlsn._store.get_tags_for_room = Mock(
-            side_effect=lambda user_id, room_id: make_awaitable({})
-        )
+        self._rlsn._store.get_tags_for_room = Mock(return_value=make_awaitable({}))
 
     @override_config({"hs_disabled": True})
     def test_maybe_send_server_notice_disabled_hs(self):
@@ -158,7 +156,7 @@ class TestResourceLimitsServerNotices(unittest.HomeserverTestCase):
         """
         self._rlsn._auth.check_auth_blocking = Mock(return_value=defer.succeed(None))
         self._rlsn._store.user_last_seen_monthly_active = Mock(
-            side_effect=lambda user_id: make_awaitable(None)
+            return_value=make_awaitable(None)
         )
         self.get_success(self._rlsn.maybe_send_server_notice_to_user(self.user_id))
 
@@ -261,12 +259,10 @@ class TestResourceLimitsServerNoticesWithRealRooms(unittest.HomeserverTestCase):
         self.user_id = "@user_id:test"
 
     def test_server_notice_only_sent_once(self):
-        self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(1000)
-        )
+        self.store.get_monthly_active_count = Mock(return_value=make_awaitable(1000))
 
         self.store.user_last_seen_monthly_active = Mock(
-            side_effect=lambda user_id: make_awaitable(1000)
+            return_value=make_awaitable(1000)
         )
 
         # Call the function multiple times to ensure we only send the notice once
diff --git a/tests/storage/test_client_ips.py b/tests/storage/test_client_ips.py
index 370c247e16..755c70db31 100644
--- a/tests/storage/test_client_ips.py
+++ b/tests/storage/test_client_ips.py
@@ -154,7 +154,7 @@ class ClientIpStoreTestCase(unittest.HomeserverTestCase):
         user_id = "@user:server"
 
         self.store.get_monthly_active_count = Mock(
-            side_effect=lambda: make_awaitable(lots_of_users)
+            return_value=make_awaitable(lots_of_users)
         )
         self.get_success(
             self.store.insert_client_ip(
diff --git a/tests/storage/test_monthly_active_users.py b/tests/storage/test_monthly_active_users.py
index 9870c74883..643072bbaf 100644
--- a/tests/storage/test_monthly_active_users.py
+++ b/tests/storage/test_monthly_active_users.py
@@ -231,9 +231,7 @@ class MonthlyActiveUsersTestCase(unittest.HomeserverTestCase):
         )
         self.get_success(d)
 
-        self.store.upsert_monthly_active_user = Mock(
-            side_effect=lambda user_id: make_awaitable(None)
-        )
+        self.store.upsert_monthly_active_user = Mock(return_value=make_awaitable(None))
 
         d = self.store.populate_monthly_active_users(user_id)
         self.get_success(d)
@@ -241,9 +239,7 @@ class MonthlyActiveUsersTestCase(unittest.HomeserverTestCase):
         self.store.upsert_monthly_active_user.assert_not_called()
 
     def test_populate_monthly_users_should_update(self):
-        self.store.upsert_monthly_active_user = Mock(
-            side_effect=lambda user_id: make_awaitable(None)
-        )
+        self.store.upsert_monthly_active_user = Mock(return_value=make_awaitable(None))
 
         self.store.is_trial_user = Mock(return_value=defer.succeed(False))
 
@@ -256,9 +252,7 @@ class MonthlyActiveUsersTestCase(unittest.HomeserverTestCase):
         self.store.upsert_monthly_active_user.assert_called_once()
 
     def test_populate_monthly_users_should_not_update(self):
-        self.store.upsert_monthly_active_user = Mock(
-            side_effect=lambda user_id: make_awaitable(None)
-        )
+        self.store.upsert_monthly_active_user = Mock(return_value=make_awaitable(None))
 
         self.store.is_trial_user = Mock(return_value=defer.succeed(False))
         self.store.user_last_seen_monthly_active = Mock(
@@ -344,9 +338,7 @@ class MonthlyActiveUsersTestCase(unittest.HomeserverTestCase):
 
     @override_config({"limit_usage_by_mau": False, "mau_stats_only": False})
     def test_no_users_when_not_tracking(self):
-        self.store.upsert_monthly_active_user = Mock(
-            side_effect=lambda user_id: make_awaitable(None)
-        )
+        self.store.upsert_monthly_active_user = Mock(return_value=make_awaitable(None))
 
         self.get_success(self.store.populate_monthly_active_users("@user:sever"))
 
diff --git a/tests/test_utils/__init__.py b/tests/test_utils/__init__.py
index 508aeba078..a298cc0fd3 100644
--- a/tests/test_utils/__init__.py
+++ b/tests/test_utils/__init__.py
@@ -17,6 +17,7 @@
 """
 Utilities for running the unit tests
 """
+from asyncio import Future
 from typing import Any, Awaitable, TypeVar
 
 TV = TypeVar("TV")
@@ -38,6 +39,12 @@ def get_awaitable_result(awaitable: Awaitable[TV]) -> TV:
     raise Exception("awaitable has not yet completed")
 
 
-async def make_awaitable(result: Any):
-    """Create an awaitable that just returns a result."""
-    return result
+def make_awaitable(result: Any) -> Awaitable[Any]:
+    """
+    Makes an awaitable, suitable for mocking an `async` function.
+    This uses Futures as they can be awaited multiple times so can be returned
+    to multiple callers.
+    """
+    future = Future()  # type: ignore
+    future.set_result(result)
+    return future