Added `do_try_state_for_outbound_lanes` which checks unpruned messages

bridges/modules/messages/src/lib.rs

@@ -575,6 +575,14 @@ pub mod pallet {
 		}
 	}
 
+	#[pallet::hooks]
+	impl<T: Config<I>, I: 'static> Hooks<BlockNumberFor<T>> for Pallet<T, I> {
+		#[cfg(feature = "try-runtime")]
+		fn try_state(_n: BlockNumberFor<T>) -> Result<(), sp_runtime::TryRuntimeError> {
+			Self::do_try_state()
+		}
+	}
+
 	impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		/// Get stored data of the outbound message with given nonce.
 		pub fn outbound_message_data(lane: LaneId, nonce: MessageNonce) -> Option<MessagePayload> {
@@ -609,6 +617,60 @@ pub mod pallet {
 		}
 	}
 
+	#[cfg(any(feature = "try-runtime", test))]
+	impl<T: Config<I>, I: 'static> Pallet<T, I> {
+		/// Ensure the correctness of the state of this pallet.
+		pub fn do_try_state() -> Result<(), sp_runtime::TryRuntimeError> {
+			Self::do_try_state_for_outbound_lanes()
+		}
+
+		/// Ensure the correctness of the state of outbound lanes.
+		pub fn do_try_state_for_outbound_lanes() -> Result<(), sp_runtime::TryRuntimeError> {
+			use sp_runtime::traits::One;
+			use sp_std::vec::Vec;
+
+			// collect unpruned lanes
+			let mut unpruned_lanes = Vec::new();
+			for (lane_id, lane_data) in OutboundLanes::<T, I>::iter() {
+				let Some(expected_last_prunned_nonce) =
+					lane_data.oldest_unpruned_nonce.checked_sub(One::one())
+				else {
+					continue;
+				};
+
+				// collect message_nonces that were supposed to be pruned
+				let mut unpruned_message_nonces = Vec::new();
+				let mut nonce_to_check = expected_last_prunned_nonce;
+				loop {
+					if OutboundMessages::<T, I>::contains_key(MessageKey {
+						lane_id,
+						nonce: nonce_to_check,
+					}) {
+						unpruned_message_nonces.push(nonce_to_check);
+					}
+					if let Some(new_nonce_to_check) = nonce_to_check.checked_sub(One::one()) {
+						nonce_to_check = new_nonce_to_check;
+					} else {
+						break;
+					}
+				}
+
+				if !unpruned_message_nonces.is_empty() {
+					log::warn!(
+						target: LOG_TARGET,
+						"do_try_state_for_outbound_lanes for lane_id: {lane_id:?} with lane_data: {lane_data:?} found unpruned_message_nonces: {unpruned_message_nonces:?}",
+					);
+					unpruned_lanes.push((lane_id, lane_data, unpruned_message_nonces));
+				}
+			}
+
+			// ensure messages before `oldest_unpruned_nonce` are really pruned.
+			ensure!(unpruned_lanes.is_empty(), "Found unpruned lanes!");
+
+			Ok(())
+		}
+	}
+
 	/// Get-parameter that returns number of active outbound lanes that the pallet maintains.
 	pub struct MaybeOutboundLanesCount<T, I>(PhantomData<(T, I)>);
 

bridges/modules/messages/src/tests/pallet_tests.rs

@@ -98,6 +98,7 @@ fn receive_messages_delivery_proof() {
 			last_delivered_nonce: 1,
 		},
 	));
+	assert_ok!(Pallet::<TestRuntime>::do_try_state());
 
 	assert_eq!(
 		System::<TestRuntime>::events(),
@@ -159,6 +160,7 @@ fn pallet_rejects_transactions_if_halted() {
 			),
 			Error::<TestRuntime, ()>::BridgeModule(bp_runtime::OwnedBridgeModuleError::Halted),
 		);
+		assert_ok!(Pallet::<TestRuntime>::do_try_state());
 	});
 }
 
@@ -219,6 +221,7 @@ fn pallet_rejects_new_messages_in_rejecting_outbound_messages_operating_mode() {
 				last_delivered_nonce: 1,
 			},
 		));
+		assert_ok!(Pallet::<TestRuntime>::do_try_state());
 	});
 }
 
@@ -394,10 +397,14 @@ fn receive_messages_proof_rejects_proof_with_too_many_messages() {
 #[test]
 fn receive_messages_delivery_proof_works() {
 	run_test(|| {
+		assert_eq!(OutboundLanes::<TestRuntime, ()>::get(TEST_LANE_ID).latest_received_nonce, 0);
+		assert_eq!(OutboundLanes::<TestRuntime, ()>::get(TEST_LANE_ID).oldest_unpruned_nonce, 1);
+
 		send_regular_message(TEST_LANE_ID);
 		receive_messages_delivery_proof();
 
-		assert_eq!(OutboundLanes::<TestRuntime, ()>::get(TEST_LANE_ID).latest_received_nonce, 1,);
+		assert_eq!(OutboundLanes::<TestRuntime, ()>::get(TEST_LANE_ID).latest_received_nonce, 1);
+		assert_eq!(OutboundLanes::<TestRuntime, ()>::get(TEST_LANE_ID).oldest_unpruned_nonce, 2);
 	});
 }
 
@@ -427,6 +434,7 @@ fn receive_messages_delivery_proof_rewards_relayers() {
 			},
 		);
 		assert_ok!(result);
+		assert_ok!(Pallet::<TestRuntime>::do_try_state());
 		assert_eq!(
 			result.unwrap().actual_weight.unwrap(),
 			TestWeightInfo::receive_messages_delivery_proof_weight(
@@ -466,6 +474,7 @@ fn receive_messages_delivery_proof_rewards_relayers() {
 			},
 		);
 		assert_ok!(result);
+		assert_ok!(Pallet::<TestRuntime>::do_try_state());
 		// even though the pre-dispatch weight was for two messages, the actual weight is
 		// for single message only
 		assert_eq!(