Refactor the Appservice scheduler code (#5886)

Get rid of the labyrinthine `recoverer_fn` code, and clean up the startup code
(it seemed to be previously inexplicably split between
`ApplicationServiceScheduler.start` and `_Recoverer.start`).

Add some docstrings too.

1 files changed, 2 insertions, 4 deletions

diff --git a/tests/appservice/test_scheduler.py b/tests/appservice/test_scheduler.py

index 04b8c2c07c..52f89d3f83 100644
--- a/tests/appservice/test_scheduler.py
+++ b/tests/appservice/test_scheduler.py
@@ -37,11 +37,9 @@ class ApplicationServiceSchedulerTransactionCtrlTestCase(unittest.TestCase):
         self.recoverer = Mock()
         self.recoverer_fn = Mock(return_value=self.recoverer)
         self.txnctrl = _TransactionController(
-            clock=self.clock,
-            store=self.store,
-            as_api=self.as_api,
-            recoverer_fn=self.recoverer_fn,
+            clock=self.clock, store=self.store, as_api=self.as_api
         )
+        self.txnctrl.RECOVERER_CLASS = self.recoverer_fn
 
     def test_single_service_up_txn_sent(self):
         # Test: The AS is up and the txn is successfully sent.