From d6fb96e056f79de220d8d59429d89a61498e9af3 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
Date: Tue, 7 Dec 2021 16:51:53 +0000
Subject: [PATCH] Fix case in `wait_for_background_updates` where `self.store`
 does not exist (#11331)

Pull the DataStore from the HomeServer instance, which
always exists.
---
 changelog.d/11331.misc |  1 +
 tests/unittest.py      | 11 ++++-------
 2 files changed, 5 insertions(+), 7 deletions(-)
 create mode 100644 changelog.d/11331.misc

diff --git a/changelog.d/11331.misc b/changelog.d/11331.misc
new file mode 100644
index 000000000..1ab3a6a97
--- /dev/null
+++ b/changelog.d/11331.misc
@@ -0,0 +1 @@
+A test helper (`wait_for_background_updates`) no longer depends on classes defining a `store` property.
diff --git a/tests/unittest.py b/tests/unittest.py
index eea0903f0..143184836 100644
--- a/tests/unittest.py
+++ b/tests/unittest.py
@@ -331,16 +331,13 @@ class HomeserverTestCase(TestCase):
             time.sleep(0.01)
 
     def wait_for_background_updates(self) -> None:
-        """Block until all background database updates have completed.
-
-        Note that callers must ensure there's a store property created on the
-        testcase.
-        """
+        """Block until all background database updates have completed."""
+        store = self.hs.get_datastore()
         while not self.get_success(
-            self.store.db_pool.updates.has_completed_background_updates()
+            store.db_pool.updates.has_completed_background_updates()
         ):
             self.get_success(
-                self.store.db_pool.updates.do_next_background_update(False), by=0.1
+                store.db_pool.updates.do_next_background_update(False), by=0.1
             )
 
     def make_homeserver(self, reactor, clock):