tests: Add assert_memcached_count.

We use a specific name to distinguish from other caches
like per-request caches.

zerver/lib/test_classes.py

@@ -70,7 +70,12 @@ from zerver.lib.test_console_output import (
     tee_stderr_and_find_extra_console_output,
     tee_stdout_and_find_extra_console_output,
 )
-from zerver.lib.test_helpers import find_key_by_email, instrument_url, queries_captured
+from zerver.lib.test_helpers import (
+    cache_tries_captured,
+    find_key_by_email,
+    instrument_url,
+    queries_captured,
+)
 from zerver.lib.topic import RESOLVED_TOPIC_PREFIX, filter_by_topic_name_via_message
 from zerver.lib.user_groups import get_system_user_group_for_user
 from zerver.lib.users import get_api_key
@@ -1223,6 +1228,12 @@ Output:
             print(f"\nexpected length: {count}\nactual length: {actual_count}")
             raise AssertionError(f"{type(items)} is of unexpected size!")
 
+    @contextmanager
+    def assert_memcached_count(self, count: int) -> Iterator[None]:
+        with cache_tries_captured() as cache_tries:
+            yield
+        self.assert_length(cache_tries, count)
+
     @contextmanager
     def assert_database_query_count(
         self, count: int, include_savepoints: bool = False, keep_cache_warm: bool = False

zerver/tests/test_digest.py

@@ -24,7 +24,6 @@ from zerver.lib.digest import (
 from zerver.lib.message import get_last_message_id
 from zerver.lib.streams import create_stream_if_needed
 from zerver.lib.test_classes import ZulipTestCase
-from zerver.lib.test_helpers import cache_tries_captured
 from zerver.models import (
     Client,
     Message,
@@ -209,11 +208,9 @@ class TestDigestEmailMessages(ZulipTestCase):
             digest_user_ids = [user.id for user in digest_users]
 
             with self.assert_database_query_count(12):
-                with cache_tries_captured() as cache_tries:
+                with self.assert_memcached_count(0):
                     bulk_handle_digest_email(digest_user_ids, cutoff)
 
-            self.assert_length(cache_tries, 0)
-
         self.assert_length(digest_users, mock_send_future_email.call_count)
 
         for i, digest_user in enumerate(digest_users):

zerver/tests/test_message_edit.py

@@ -21,7 +21,7 @@ from zerver.actions.user_topics import do_set_user_topic_visibility_policy
 from zerver.actions.users import do_change_user_role
 from zerver.lib.message import MessageDict, has_message_access, messages_for_ids, truncate_topic
 from zerver.lib.test_classes import ZulipTestCase, get_topic_messages
-from zerver.lib.test_helpers import cache_tries_captured, queries_captured
+from zerver.lib.test_helpers import queries_captured
 from zerver.lib.topic import RESOLVED_TOPIC_PREFIX, TOPIC_NAME
 from zerver.lib.url_encoding import near_stream_message_url
 from zerver.lib.user_topics import (
@@ -3691,7 +3691,7 @@ class EditMessageTest(EditMessageTestCase):
             "iago", "test move stream", "new stream", "test"
         )
 
-        with self.assert_database_query_count(56), cache_tries_captured() as cache_tries:
+        with self.assert_database_query_count(56), self.assert_memcached_count(13):
             result = self.client_patch(
                 f"/json/messages/{msg_id}",
                 {
@@ -3701,7 +3701,6 @@ class EditMessageTest(EditMessageTestCase):
                     "topic": "new topic",
                 },
             )
-        self.assert_length(cache_tries, 13)
 
         messages = get_topic_messages(user_profile, old_stream, "test")
         self.assert_length(messages, 1)

zerver/tests/test_signup.py

@@ -52,7 +52,6 @@ from zerver.lib.test_classes import ZulipTestCase
 from zerver.lib.test_helpers import (
     HostRequestMock,
     avatar_disk_path,
-    cache_tries_captured,
     find_key_by_email,
     get_test_image_file,
     load_subdomain_token,
@@ -929,15 +928,13 @@ class LoginTest(ZulipTestCase):
         ContentType.objects.clear_cache()
 
         # Ensure the number of queries we make is not O(streams)
-        with self.assert_database_query_count(104), cache_tries_captured() as cache_tries:
-            with self.captureOnCommitCallbacks(execute=True):
-                self.register(self.nonreg_email("test"), "test")
-
         # We can probably avoid a couple cache hits here, but there doesn't
         # seem to be any O(N) behavior.  Some of the cache hits are related
         # to sending messages, such as getting the welcome bot, looking up
         # the alert words for a realm, etc.
-        self.assert_length(cache_tries, 19)
+        with self.assert_database_query_count(104), self.assert_memcached_count(19):
+            with self.captureOnCommitCallbacks(execute=True):
+                self.register(self.nonreg_email("test"), "test")
 
         user_profile = self.nonreg_user("test")
         self.assert_logged_in_user_id(user_profile.id)

zerver/tests/test_subs.py

@@ -4944,7 +4944,7 @@ class SubscriptionAPITest(ZulipTestCase):
         # Sends 3 peer-remove events and 2 unsubscribe events.
         with self.capture_send_event_calls(expected_num_events=5) as events:
             with self.assert_database_query_count(16):
-                with cache_tries_captured() as cache_count:
+                with self.assert_memcached_count(3):
                     bulk_remove_subscriptions(
                         realm,
                         [user1, user2],
@@ -4952,8 +4952,6 @@ class SubscriptionAPITest(ZulipTestCase):
                         acting_user=None,
                     )
 
-        self.assert_length(cache_count, 3)
-
         peer_events = [e for e in events if e["event"].get("op") == "peer_remove"]
 
         # We only care about a subset of users when we inspect
@@ -5081,8 +5079,11 @@ class SubscriptionAPITest(ZulipTestCase):
 
         test_user_ids = [user.id for user in test_users]
 
+        # The only known O(N) behavior here is that we call
+        # principal_to_user_profile for each of our users, but it
+        # should be cached.
         with self.assert_database_query_count(21):
-            with cache_tries_captured() as cache_tries:
+            with self.assert_memcached_count(3):
                 with mock.patch("zerver.views.streams.send_messages_for_new_subscribers"):
                     self.common_subscribe_to_streams(
                         desdemona,
@@ -5090,10 +5091,6 @@ class SubscriptionAPITest(ZulipTestCase):
                         dict(principals=orjson.dumps(test_user_ids).decode()),
                     )
 
-        # The only known O(N) behavior here is that we call
-        # principal_to_user_profile for each of our users.
-        self.assert_length(cache_tries, 3)
-
     def test_subscriptions_add_for_principal(self) -> None:
         """
         You can subscribe other people to streams.

zerver/tests/test_users.py

@@ -40,7 +40,6 @@ from zerver.lib.send_email import (
 from zerver.lib.stream_topic import StreamTopicTarget
 from zerver.lib.test_classes import ZulipTestCase
 from zerver.lib.test_helpers import (
-    cache_tries_captured,
     get_subscription,
     get_test_image_file,
     reset_email_visibility_to_everyone_in_zulip_realm,
@@ -795,7 +794,7 @@ class QueryCountTest(ZulipTestCase):
         prereg_user = PreregistrationUser.objects.get(email="fred@zulip.com")
 
         with self.assert_database_query_count(93):
-            with cache_tries_captured() as cache_tries:
+            with self.assert_memcached_count(24):
                 with self.capture_send_event_calls(expected_num_events=11) as events:
                     fred = do_create_user(
                         email="fred@zulip.com",
@@ -806,7 +805,6 @@ class QueryCountTest(ZulipTestCase):
                         acting_user=None,
                     )
 
-        self.assert_length(cache_tries, 24)
         peer_add_events = [event for event in events if event["event"].get("op") == "peer_add"]
 
         notifications = set()