[stable2412] Backport #7691

cumulus/parachains/integration-tests/emulated/common/Cargo.toml

@@ -42,14 +42,14 @@ polkadot-runtime-parachains.workspace = true
 polkadot-runtime-parachains.default-features = true
 xcm.workspace = true
 xcm.default-features = true
-pallet-xcm.workspace = true
-pallet-xcm.default-features = true
+pallet-xcm = { features = ["test-utils"], workspace = true, default-features = true }
 parachains-common.workspace = true
 parachains-common.default-features = true
 cumulus-primitives-core.workspace = true
 cumulus-primitives-core.default-features = true
 xcm-emulator.workspace = true
 xcm-emulator.default-features = true
+xcm-simulator = { workspace = true, default-features = true }
 cumulus-pallet-xcmp-queue.workspace = true
 cumulus-pallet-xcmp-queue.default-features = true
 cumulus-pallet-parachain-system.workspace = true

cumulus/parachains/integration-tests/emulated/common/src/lib.rs

@@ -18,6 +18,7 @@ pub mod macros;
 pub mod xcm_helpers;
 
 pub use xcm_emulator;
+pub use xcm_simulator;
 
 // Substrate
 use frame_support::parameter_types;

cumulus/parachains/integration-tests/emulated/common/src/xcm_helpers.rs

@@ -17,7 +17,9 @@
 use parachains_common::AccountId;
 
 // Polkadot
+use sp_core::H256;
 use xcm::{prelude::*, DoubleEncoded};
+use xcm_emulator::Chain;
 
 /// Helper method to build a XCM with a `Transact` instruction and paying for its execution
 pub fn xcm_transact_paid_execution(
@@ -74,3 +76,29 @@ pub fn get_amount_from_versioned_assets(assets: VersionedAssets) -> u128 {
 	};
 	amount
 }
+
+/// Helper method to find the ID of the first `Event::Processed` event in the chain's events.
+pub fn find_mq_processed_id<C: Chain>() -> Option<H256>
+where
+	<C as Chain>::Runtime: pallet_message_queue::Config,
+	C::RuntimeEvent: TryInto<pallet_message_queue::Event<<C as Chain>::Runtime>>,
+{
+	C::events().into_iter().find_map(|event| {
+		if let Ok(pallet_message_queue::Event::Processed { id, .. }) = event.try_into() {
+			Some(id)
+		} else {
+			None
+		}
+	})
+}
+
+/// Helper method to find the message ID of the first `Event::Sent` event in the chain's events.
+pub fn find_xcm_sent_message_id<
+	C: Chain<RuntimeEvent = <<C as Chain>::Runtime as pallet_xcm::Config>::RuntimeEvent>,
+>() -> Option<XcmHash>
+where
+	C::Runtime: pallet_xcm::Config,
+	C::RuntimeEvent: TryInto<pallet_xcm::Event<C::Runtime>>,
+{
+	pallet_xcm::xcm_helpers::find_xcm_sent_message_id::<<C as Chain>::Runtime>(C::events())
+}

cumulus/parachains/integration-tests/emulated/tests/assets/asset-hub-westend/src/tests/hybrid_transfers.rs

@@ -18,8 +18,9 @@ use crate::{
 	imports::*,
 	tests::teleport::do_bidirectional_teleport_foreign_assets_between_para_and_asset_hub_using_xt,
 };
+use emulated_integration_tests_common::xcm_helpers::find_mq_processed_id;
 
-fn para_to_para_assethub_hop_assertions(t: ParaToParaThroughAHTest) {
+fn para_to_para_assethub_hop_assertions(mut t: ParaToParaThroughAHTest) {
 	type RuntimeEvent = <AssetHubWestend as Chain>::RuntimeEvent;
 	let sov_penpal_a_on_ah = AssetHubWestend::sovereign_account_id_of(
 		AssetHubWestend::sibling_location_of(PenpalA::para_id()),
@@ -49,6 +50,9 @@ fn para_to_para_assethub_hop_assertions(t: ParaToParaThroughAHTest) {
 			) => {},
 		]
 	);
+
+	let mq_prc_id = find_mq_processed_id::<AssetHubWestend>().expect("Missing Processed Event");
+	t.insert_unique_topic_id("AssetHubWestend", mq_prc_id);
 }
 
 fn ah_to_para_transfer_assets(t: SystemParaToParaTest) -> DispatchResult {
@@ -586,6 +590,9 @@ fn transfer_foreign_assets_from_para_to_para_through_asset_hub() {
 	test.set_dispatchable::<PenpalA>(para_to_para_transfer_assets_through_ah);
 	test.assert();
 
+	// assert unique topic across all chains
+	test.assert_unique_topic_id();
+
 	// Query final balances
 	let sender_wnds_after = PenpalA::execute_with(|| {
 		type ForeignAssets = <PenpalA as PenpalAPallet>::ForeignAssets;

cumulus/parachains/integration-tests/emulated/tests/assets/asset-hub-westend/src/tests/reserve_transfer.rs

@@ -14,6 +14,7 @@
 // limitations under the License.
 
 use crate::{create_pool_with_wnd_on, foreign_balance_on, imports::*};
+use emulated_integration_tests_common::xcm_helpers::find_mq_processed_id;
 use sp_core::{crypto::get_public_from_string_or_panic, sr25519};
 
 fn relay_to_para_sender_assertions(t: RelayToParaTest) {
@@ -468,10 +469,16 @@ fn para_to_para_asset_hub_hop_assertions(t: ParaToParaThroughAHTest) {
 	);
 }
 
-pub fn para_to_para_through_hop_receiver_assertions<Hop: Clone>(t: Test<PenpalA, PenpalB, Hop>) {
+pub fn para_to_para_through_hop_receiver_assertions<Hop: Clone>(
+	mut t: Test<PenpalA, PenpalB, Hop>,
+) {
 	type RuntimeEvent = <PenpalB as Chain>::RuntimeEvent;
 
 	PenpalB::assert_xcmp_queue_success(None);
+
+	let mq_prc_id = find_mq_processed_id::<PenpalB>().expect("Missing Processed Event");
+	t.insert_unique_topic_id("PenpalB", mq_prc_id);
+
 	for asset in t.args.assets.into_inner().into_iter() {
 		let expected_id = asset.id.0.try_into().unwrap();
 		assert_expected_events!(

cumulus/parachains/integration-tests/emulated/tests/bridges/bridge-hub-westend/src/tests/asset_transfers.rs

@@ -14,6 +14,9 @@
 // limitations under the License.
 
 use crate::{create_pool_with_native_on, tests::*};
+use emulated_integration_tests_common::{
+	xcm_helpers::find_mq_processed_id, xcm_simulator::helpers::TopicIdTracker,
+};
 use xcm::latest::AssetTransferFilter;
 
 fn send_assets_over_bridge<F: FnOnce()>(send_fn: F) {
@@ -553,6 +556,7 @@ fn dry_run_transfer_to_rococo_sends_xcm_to_bridge_hub() {
 }
 
 fn do_send_pens_and_wnds_from_penpal_westend_via_ahw_to_asset_hub_rococo(
+	topic_id_tracker: &mut TopicIdTracker,
 	wnds: (Location, u128),
 	pens: (Location, u128),
 ) {
@@ -652,6 +656,9 @@ fn do_send_pens_and_wnds_from_penpal_westend_via_ahw_to_asset_hub_rococo(
 		}));
 		AssetHubWestend::execute_with(|| {
 			type RuntimeEvent = <AssetHubWestend as Chain>::RuntimeEvent;
+			let mq_prc_id =
+				find_mq_processed_id::<AssetHubWestend>().expect("Missing Processed Event");
+			topic_id_tracker.insert_and_assert_unique("AssetHubWestend", mq_prc_id);
 			assert_expected_events!(
 				AssetHubWestend,
 				vec![
@@ -672,6 +679,12 @@ fn do_send_pens_and_wnds_from_penpal_westend_via_ahw_to_asset_hub_rococo(
 				]
 			);
 		});
+
+		BridgeHubWestend::ext_wrapper(|| {
+			let mq_prc_id =
+				find_mq_processed_id::<BridgeHubWestend>().expect("Missing Processed Event");
+			topic_id_tracker.insert_and_assert_unique("BridgeHubWestend", mq_prc_id);
+		});
 	});
 }
 
@@ -776,14 +789,20 @@ fn send_pens_and_wnds_from_penpal_westend_via_ahw_to_ahr() {
 		)
 	});
 
+	// init topic ID tracker
+	let mut topic_id_tracker = TopicIdTracker::new();
+
 	// transfer assets
 	do_send_pens_and_wnds_from_penpal_westend_via_ahw_to_asset_hub_rococo(
+		&mut topic_id_tracker,
 		(wnd_at_westend_parachains.clone(), wnds_to_send),
 		(pens_location_on_penpal.try_into().unwrap(), pens_to_send),
 	);
 
 	AssetHubRococo::execute_with(|| {
 		type RuntimeEvent = <AssetHubRococo as Chain>::RuntimeEvent;
+		let mq_prc_id = find_mq_processed_id::<AssetHubRococo>().expect("Missing Processed Event");
+		topic_id_tracker.insert_and_assert_unique("AssetHubRococo", mq_prc_id);
 		assert_expected_events!(
 			AssetHubRococo,
 			vec![
@@ -800,6 +819,9 @@ fn send_pens_and_wnds_from_penpal_westend_via_ahw_to_ahr() {
 		);
 	});
 
+	// assert unique topic across all chains
+	topic_id_tracker.assert_unique();
+
 	// account balances after
 	let sender_wnds_after = PenpalB::execute_with(|| {
 		type ForeignAssets = <PenpalB as PenpalBPallet>::ForeignAssets;

cumulus/parachains/integration-tests/emulated/tests/bridges/bridge-hub-westend/src/tests/mod.rs

@@ -230,7 +230,7 @@ pub(crate) fn assert_bridge_hub_westend_message_accepted(expected_processed: boo
 				]
 			);
 		}
-	});
+	})
 }
 
 pub(crate) fn assert_bridge_hub_rococo_message_received() {

cumulus/xcm/xcm-emulator/Cargo.toml

@@ -53,6 +53,7 @@ xcm.workspace = true
 xcm.default-features = true
 xcm-executor.workspace = true
 xcm-executor.default-features = true
+xcm-simulator = { workspace = true, default-features = true }
 polkadot-primitives.workspace = true
 polkadot-primitives.default-features = true
 polkadot-parachain-primitives.workspace = true

cumulus/xcm/xcm-emulator/src/lib.rs

@@ -20,6 +20,7 @@ pub use array_bytes;
 pub use codec::{Decode, Encode, EncodeLike, MaxEncodedLen};
 pub use log;
 pub use paste;
+use std::sync::Arc;
 pub use std::{
 	any::type_name,
 	collections::HashMap,
@@ -75,12 +76,13 @@ pub use polkadot_runtime_parachains::inclusion::{AggregateMessageOrigin, UmpQueu
 
 // Polkadot
 pub use polkadot_parachain_primitives::primitives::RelayChainBlockNumber;
-use sp_core::crypto::AccountId32;
+use sp_core::{crypto::AccountId32, H256};
 pub use xcm::latest::prelude::{
 	AccountId32 as AccountId32Junction, Ancestor, Assets, Here, Location,
 	Parachain as ParachainJunction, Parent, WeightLimit, XcmHash,
 };
 pub use xcm_executor::traits::ConvertLocation;
+use xcm_simulator::helpers::TopicIdTracker;
 
 pub type AccountIdOf<T> = <T as frame_system::Config>::AccountId;
 
@@ -1545,11 +1547,30 @@ where
 	pub hops_dispatchable: HashMap<String, fn(Self) -> DispatchResult>,
 	pub hops_calls: HashMap<String, Origin::RuntimeCall>,
 	pub args: Args,
+	topic_id_tracker: Arc<Mutex<TopicIdTracker>>,
 	_marker: PhantomData<(Destination, Hops)>,
 }
 
 /// `Test` implementation.
 impl<Origin, Destination, Hops, Args> Test<Origin, Destination, Hops, Args>
+where
+	Args: Clone,
+	Origin: Chain + Clone,
+	Destination: Chain + Clone,
+	Origin::RuntimeOrigin: OriginTrait<AccountId = AccountIdOf<Origin::Runtime>> + Clone,
+	Destination::RuntimeOrigin: OriginTrait<AccountId = AccountIdOf<Destination::Runtime>> + Clone,
+	Hops: Clone,
+{
+	/// Asserts that a single unique topic ID exists across all chains.
+	pub fn assert_unique_topic_id(&self) {
+		self.topic_id_tracker.lock().unwrap().assert_unique();
+	}
+	/// Inserts a topic ID for a specific chain and asserts it remains globally unique.
+	pub fn insert_unique_topic_id(&mut self, chain: &str, id: H256) {
+		self.topic_id_tracker.lock().unwrap().insert_and_assert_unique(chain, id);
+	}
+}
+impl<Origin, Destination, Hops, Args> Test<Origin, Destination, Hops, Args>
 where
 	Args: Clone,
 	Origin: Chain + Clone + CheckAssertion<Origin, Destination, Hops, Args>,
@@ -1575,6 +1596,7 @@ where
 			hops_dispatchable: Default::default(),
 			hops_calls: Default::default(),
 			args: test_args.args,
+			topic_id_tracker: Arc::new(Mutex::new(TopicIdTracker::new())),
 			_marker: Default::default(),
 		}
 	}

polkadot/xcm/pallet-xcm/Cargo.toml

@@ -31,6 +31,7 @@ pallet-balances = { optional = true, workspace = true }
 pallet-assets = { default-features = true, path = "../../../substrate/frame/assets" }
 polkadot-runtime-parachains = { default-features = true, path = "../../runtime/parachains" }
 polkadot-parachain-primitives = { default-features = true, path = "../../parachain" }
+xcm-simulator = { workspace = true, default-features = true }
 
 [features]
 default = ["std"]
@@ -62,6 +63,7 @@ runtime-benchmarks = [
 	"xcm-executor/runtime-benchmarks",
 	"xcm-runtime-apis/runtime-benchmarks",
 ]
+test-utils = ["std"]
 try-runtime = [
 	"frame-support/try-runtime",
 	"frame-system/try-runtime",

polkadot/xcm/pallet-xcm/src/lib.rs

@@ -26,6 +26,8 @@ mod mock;
 mod tests;
 
 pub mod migration;
+#[cfg(any(test, feature = "test-utils"))]
+pub mod xcm_helpers;
 
 extern crate alloc;