diff --git a/tests/storage/databases/main/test_events_worker.py b/tests/storage/databases/main/test_events_worker.py
index 788500e38f..b223dc750b 100644
--- a/tests/storage/databases/main/test_events_worker.py
+++ b/tests/storage/databases/main/test_events_worker.py
@@ -139,6 +139,55 @@ class HaveSeenEventsTestCase(unittest.HomeserverTestCase):
# That should result in a single db query to lookup
self.assertEqual(ctx.get_resource_usage().db_txn_count, 1)
+ def test_persisting_event_prefills_get_event_cache(self) -> None:
+ """
+ Test to make sure that the `_get_event_cache` is prefilled after we persist an
+ event and returns the updated value.
+ """
+ event, event_context = self.get_success(
+ create_event(
+ self.hs,
+ room_id=self.room_id,
+ sender=self.user,
+ type="test_event_type",
+ content={"body": "conflabulation"},
+ )
+ )
+
+ # First, check `_get_event_cache` for the event we just made
+ # to verify it's not in the cache.
+ res = self.store._get_event_cache.get_local((event.event_id,))
+ self.assertEqual(res, None, "Event was cached when it should not have been.")
+
+ with LoggingContext(name="test") as ctx:
+ # Persist the event which should invalidate then prefill the
+ # `_get_event_cache` so we don't return stale values.
+ # Side Note: Apparently, persisting an event isn't a transaction in the
+ # sense that it is recorded in the LoggingContext
+ persistence = self.hs.get_storage_controllers().persistence
+ assert persistence is not None
+ self.get_success(
+ persistence.persist_event(
+ event,
+ event_context,
+ )
+ )
+
+ # Check `_get_event_cache` again and we should see the updated fact
+ # that we now have the event cached after persisting it.
+ res = self.store._get_event_cache.get_local((event.event_id,))
+ self.assertEqual(res.event, event, "Event not cached as expected.") # type: ignore
+
+ # Try and fetch the event from the database.
+ self.get_success(self.store.get_event(event.event_id))
+
+ # Verify that the database hit was avoided.
+ self.assertEqual(
+ ctx.get_resource_usage().evt_db_fetch_count,
+ 0,
+ "Database was hit, which would not happen if event was cached.",
+ )
+
def test_invalidate_cache_by_room_id(self) -> None:
"""
Test to make sure that all events associated with the given `(room_id,)`
|
