Fix background_update tests

A bit of a cleanup for background_updates, and make sure that the real
background updates have run before we start the unit tests, so that they don't
interfere with the tests.

1 files changed, 16 insertions, 6 deletions

diff --git a/tests/storage/test_background_update.py b/tests/storage/test_background_update.py
index 6e4d9b1373..4944cb0d2e 100644
--- a/tests/storage/test_background_update.py
+++ b/tests/storage/test_background_update.py
@@ -10,7 +10,7 @@ class BackgroundUpdateTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def setUp(self):
-        hs = yield setup_test_homeserver()
+        hs = yield setup_test_homeserver()  # type: synapse.server.HomeServer
         self.store = hs.get_datastore()
         self.clock = hs.get_clock()
 
@@ -20,11 +20,20 @@ class BackgroundUpdateTestCase(unittest.TestCase):
             "test_update", self.update_handler
         )
 
+        # run the real background updates, to get them out the way
+        # (perhaps we should run them as part of the test HS setup, since we
+        # run all of the other schema setup stuff there?)
+        while True:
+            res = yield self.store.do_next_background_update(1000)
+            if res is None:
+                break
+
     @defer.inlineCallbacks
     def test_do_background_update(self):
         desired_count = 1000
         duration_ms = 42
 
+        # first step: make a bit of progress
         @defer.inlineCallbacks
         def update(progress, count):
             self.clock.advance_time_msec(count * duration_ms)
@@ -42,7 +51,7 @@ class BackgroundUpdateTestCase(unittest.TestCase):
         yield self.store.start_background_update("test_update", {"my_key": 1})
 
         self.update_handler.reset_mock()
-        result = yield self.store.do_background_update(
+        result = yield self.store.do_next_background_update(
             duration_ms * desired_count
         )
         self.assertIsNotNone(result)
@@ -50,24 +59,25 @@ class BackgroundUpdateTestCase(unittest.TestCase):
             {"my_key": 1}, self.store.DEFAULT_BACKGROUND_BATCH_SIZE
         )
 
+        # second step: complete the update
         @defer.inlineCallbacks
         def update(progress, count):
             yield self.store._end_background_update("test_update")
             defer.returnValue(count)
 
         self.update_handler.side_effect = update
-
         self.update_handler.reset_mock()
-        result = yield self.store.do_background_update(
-            duration_ms * desired_count
+        result = yield self.store.do_next_background_update(
+           duration_ms * desired_count
         )
         self.assertIsNotNone(result)
         self.update_handler.assert_called_once_with(
             {"my_key": 2}, desired_count
         )
 
+        # third step: we don't expect to be called any more
         self.update_handler.reset_mock()
-        result = yield self.store.do_background_update(
+        result = yield self.store.do_next_background_update(
             duration_ms * desired_count
         )
         self.assertIsNone(result)