Update Relay Authorities Protocol (#440)

* update: relay authorities protocol

* test: `authority_term_should_work`

* update: test

frame/bridge/relay-authorities/src/lib.rs

@@ -492,9 +492,6 @@ decl_module! {
 			let (message, mut signatures) = if let Some(signatures) = <AuthoritiesToSign<T, I>>::get() {
 				signatures
 			} else {
-				// Should never enter this condition
-				// TODO: error log
-
 				return Ok(());
 			};
 
@@ -547,7 +544,6 @@ decl_module! {
 			}
 
 			<OldAuthorities<T, I>>::kill();
-			<AuthorityTerm<I>>::mutate(|term| *term += 1);
 			<AuthoritiesState<T, I>>::kill();
 			<AuthoritiesToSign<T, I>>::kill();
 			{
@@ -676,7 +672,6 @@ where
 	pub fn wait_target_chain_authorities_change() {
 		<AuthoritiesToSign<T, I>>::kill();
 		<AuthoritiesState<T, I>>::mutate(|authorities_state| authorities_state.1 = 0.into());
-		<AuthorityTerm<I>>::mutate(|authority_term| *authority_term += 1);
 
 		for account_id in <OldAuthoritiesLockToRemove<T, I>>::take() {
 			<RingCurrency<T, I>>::remove_lock(T::LockId::get(), &account_id);
@@ -771,6 +766,7 @@ where
 
 	fn finish_authorities_change() {
 		<AuthoritiesState<T, I>>::kill();
+		<AuthorityTerm<I>>::mutate(|authority_term| *authority_term += 1);
 	}
 }
 

frame/bridge/relay-authorities/src/test.rs

@@ -159,6 +159,22 @@ fn kill_candidates_should_work() {
 	});
 }
 
+#[test]
+fn authority_term_should_work() {
+	new_test_ext().execute_with(|| {
+		let max_candidates = <MaxCandidates as Get<usize>>::get();
+
+		for i in 1..=max_candidates {
+			assert_eq!(RelayAuthorities::authority_term(), i as Term - 1);
+			assert_ok!(request_authority(i as _));
+			assert_ok!(RelayAuthorities::add_authority(Origin::root(), i as _));
+
+			RelayAuthorities::finish_authorities_change();
+			assert_eq!(RelayAuthorities::authority_term(), i as Term);
+		}
+	});
+}
+
 #[test]
 fn encode_message_should_work() {
 	// --- substrate ---