Fix errors in Synapse logs from unit tests. (#10939)

Fix some harmless errors from background processes (mostly
due to awaiting Mock objects) that occurred in the Synapse
logs during unit tests.

1 files changed, 3 insertions, 3 deletions

diff --git a/tests/federation/test_federation_sender.py b/tests/federation/test_federation_sender.py

index 65b18fbd7a..b457dad6d2 100644
--- a/tests/federation/test_federation_sender.py
+++ b/tests/federation/test_federation_sender.py
@@ -336,7 +336,7 @@ class FederationSenderDevicesTestCases(HomeserverTestCase):
         recovery
         """
         mock_send_txn = self.hs.get_federation_transport_client().send_transaction
-        mock_send_txn.side_effect = lambda t, cb: defer.fail("fail")
+        mock_send_txn.side_effect = lambda t, cb: defer.fail(AssertionError("fail"))
 
         # create devices
         u1 = self.register_user("user", "pass")
@@ -376,7 +376,7 @@ class FederationSenderDevicesTestCases(HomeserverTestCase):
         This case tests the behaviour when the server has never been reachable.
         """
         mock_send_txn = self.hs.get_federation_transport_client().send_transaction
-        mock_send_txn.side_effect = lambda t, cb: defer.fail("fail")
+        mock_send_txn.side_effect = lambda t, cb: defer.fail(AssertionError("fail"))
 
         # create devices
         u1 = self.register_user("user", "pass")
@@ -429,7 +429,7 @@ class FederationSenderDevicesTestCases(HomeserverTestCase):
 
         # now the server goes offline
         mock_send_txn = self.hs.get_federation_transport_client().send_transaction
-        mock_send_txn.side_effect = lambda t, cb: defer.fail("fail")
+        mock_send_txn.side_effect = lambda t, cb: defer.fail(AssertionError("fail"))
 
         self.login("user", "pass", device_id="D2")
         self.login("user", "pass", device_id="D3")