Prefer `make_awaitable` over `defer.succeed` in tests (#12505)

When configuring the return values of mocks, prefer awaitables from
`make_awaitable` over `defer.succeed`. `Deferred`s are only awaitable
once, so it is inappropriate for a mock to return the same `Deferred`
multiple times.

Also update `run_in_background` to support functions that return
arbitrary awaitables.

Signed-off-by: Sean Quah <seanq@element.io>

1 files changed, 4 insertions, 3 deletions

diff --git a/tests/rest/client/test_transactions.py b/tests/rest/client/test_transactions.py
index 8d8251b2ac..21a1ca2a68 100644
--- a/tests/rest/client/test_transactions.py
+++ b/tests/rest/client/test_transactions.py
@@ -22,6 +22,7 @@ from synapse.rest.client.transactions import CLEANUP_PERIOD_MS, HttpTransactionC
 from synapse.util import Clock
 
 from tests import unittest
+from tests.test_utils import make_awaitable
 from tests.utils import MockClock
 
 
@@ -38,7 +39,7 @@ class HttpTransactionCacheTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_executes_given_function(self):
-        cb = Mock(return_value=defer.succeed(self.mock_http_response))
+        cb = Mock(return_value=make_awaitable(self.mock_http_response))
         res = yield self.cache.fetch_or_execute(
             self.mock_key, cb, "some_arg", keyword="arg"
         )
@@ -47,7 +48,7 @@ class HttpTransactionCacheTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_deduplicates_based_on_key(self):
-        cb = Mock(return_value=defer.succeed(self.mock_http_response))
+        cb = Mock(return_value=make_awaitable(self.mock_http_response))
         for i in range(3):  # invoke multiple times
             res = yield self.cache.fetch_or_execute(
                 self.mock_key, cb, "some_arg", keyword="arg", changing_args=i
@@ -130,7 +131,7 @@ class HttpTransactionCacheTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_cleans_up(self):
-        cb = Mock(return_value=defer.succeed(self.mock_http_response))
+        cb = Mock(return_value=make_awaitable(self.mock_http_response))
         yield self.cache.fetch_or_execute(self.mock_key, cb, "an arg")
         # should NOT have cleaned up yet
         self.clock.advance_time_msec(CLEANUP_PERIOD_MS / 2)