f use mutator

Author: TheBlueMatt

lightning/src/ln/chanmon_update_fail_tests.rs

@@ -2000,10 +2000,7 @@ fn test_path_paused_mpp() {
 	// Set it so that the first monitor update (for the path 0 -> 1 -> 3) succeeds, but the second
 	// (for the path 0 -> 2 -> 3) fails.
 	chanmon_cfgs[0].persister.set_update_ret(Ok(()));
-	{
-		let mut next_update_ret = chanmon_cfgs[0].persister.next_update_ret.lock().unwrap();
-		*next_update_ret = Some(Err(ChannelMonitorUpdateErr::TemporaryFailure));
-	}
+	chanmon_cfgs[0].persister.set_next_update_ret(Some(Err(ChannelMonitorUpdateErr::TemporaryFailure)));
 
 	// Now check that we get the right return value, indicating that the first path succeeded but
 	// the second got a MonitorUpdateFailed err. This implies PaymentSendFailure::PartialFailure as

lightning/src/util/test_utils.rs

@@ -173,6 +173,10 @@ impl TestPersister {
 	pub fn set_update_ret(&self, ret: Result<(), chain::ChannelMonitorUpdateErr>) {
 		*self.update_ret.lock().unwrap() = ret;
 	}
+
+	pub fn set_next_update_ret(&self, next_ret: Option<Result<(), chain::ChannelMonitorUpdateErr>>) {
+		*self.next_update_ret.lock().unwrap() = next_ret;
+	}
 }
 impl<Signer: keysinterface::Sign> chainmonitor::Persist<Signer> for TestPersister {
 	fn persist_new_channel(&self, _funding_txo: OutPoint, _data: &channelmonitor::ChannelMonitor<Signer>) -> Result<(), chain::ChannelMonitorUpdateErr> {