pallet-xcm: add extrinsic to allow withdrawal of reserve-based assets

cumulus/parachains/runtimes/assets/asset-hub-kusama/src/weights/pallet_xcm.rs

@@ -92,6 +92,10 @@ impl<T: frame_system::Config> pallet_xcm::WeightInfo for WeightInfo<T> {
 			.saturating_add(Weight::from_parts(0, 1489))
 			.saturating_add(T::DbWeight::get().reads(1))
 	}
+	fn reserve_withdraw_assets() -> Weight {
+		Weight::from_parts(23_000_000, 0)
+			.saturating_add(Weight::from_parts(0, 0))
+	}
 	/// Storage: `Benchmark::Override` (r:0 w:0)
 	/// Proof: `Benchmark::Override` (`max_values`: None, `max_size`: None, mode: `Measured`)
 	fn execute() -> Weight {

cumulus/parachains/runtimes/assets/asset-hub-kusama/tests/tests.rs

@@ -18,13 +18,14 @@
 //! Tests for the Statemine (Kusama Assets Hub) chain.
 
 use asset_hub_kusama_runtime::xcm_config::{
-	AssetFeeAsExistentialDepositMultiplierFeeCharger, KsmLocation, TrustBackedAssetsPalletLocation,
+	AssetFeeAsExistentialDepositMultiplierFeeCharger, KsmLocation, LocationToAccountId,
+	TrustBackedAssetsPalletLocation,
 };
 pub use asset_hub_kusama_runtime::{
 	xcm_config::{CheckingAccount, ForeignCreatorsSovereignAccountOf, XcmConfig},
 	AllPalletsWithoutSystem, AssetDeposit, Assets, Balances, ExistentialDeposit, ForeignAssets,
 	ForeignAssetsInstance, MetadataDepositBase, MetadataDepositPerByte, ParachainSystem, Runtime,
-	RuntimeCall, RuntimeEvent, SessionKeys, System, TrustBackedAssetsInstance,
+	RuntimeCall, RuntimeEvent, SessionKeys, System, TrustBackedAssetsInstance, XcmpQueue,
 };
 use asset_test_utils::{CollatorSessionKeys, ExtBuilder};
 use codec::{Decode, Encode};
@@ -632,3 +633,62 @@ asset_test_utils::include_create_and_manage_foreign_assets_for_local_consensus_p
 		assert_eq!(ForeignAssets::asset_ids().collect::<Vec<_>>().len(), 1);
 	})
 );
+
+#[test]
+fn reserve_transfer_native_asset_works() {
+	asset_test_utils::test_cases::reserve_transfer_native_asset_works::<
+		Runtime,
+		AllPalletsWithoutSystem,
+		XcmConfig,
+		ParachainSystem,
+		XcmpQueue,
+		LocationToAccountId,
+	>(
+		collator_session_keys(),
+		ExistentialDeposit::get(),
+		AccountId::from(ALICE),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::PolkadotXcm(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		WeightLimit::Unlimited,
+	);
+}
+
+#[test]
+fn reserve_withdraw_foreign_asset_works() {
+	asset_test_utils::test_cases::reserve_withdraw_foreign_asset_works::<
+		Runtime,
+		AllPalletsWithoutSystem,
+		XcmConfig,
+		ForeignAssetsInstance,
+		ParachainSystem,
+		XcmpQueue,
+		LocationToAccountId,
+	>(
+		collator_session_keys(),
+		ExistentialDeposit::get(),
+		AccountId::from(ALICE),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::PolkadotXcm(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		WeightLimit::Unlimited,
+	);
+}

cumulus/parachains/runtimes/assets/asset-hub-polkadot/src/weights/pallet_xcm.rs

@@ -92,6 +92,10 @@ impl<T: frame_system::Config> pallet_xcm::WeightInfo for WeightInfo<T> {
 			.saturating_add(Weight::from_parts(0, 1489))
 			.saturating_add(T::DbWeight::get().reads(1))
 	}
+	fn reserve_withdraw_assets() -> Weight {
+		Weight::from_parts(23_000_000, 0)
+			.saturating_add(Weight::from_parts(0, 0))
+	}
 	/// Storage: `Benchmark::Override` (r:0 w:0)
 	/// Proof: `Benchmark::Override` (`max_values`: None, `max_size`: None, mode: `Measured`)
 	fn execute() -> Weight {

cumulus/parachains/runtimes/assets/asset-hub-polkadot/tests/tests.rs

@@ -19,12 +19,13 @@
 
 use asset_hub_polkadot_runtime::xcm_config::{
 	AssetFeeAsExistentialDepositMultiplierFeeCharger, CheckingAccount, DotLocation,
-	ForeignCreatorsSovereignAccountOf, TrustBackedAssetsPalletLocation, XcmConfig,
+	ForeignCreatorsSovereignAccountOf, LocationToAccountId, TrustBackedAssetsPalletLocation,
+	XcmConfig,
 };
 pub use asset_hub_polkadot_runtime::{
 	AllPalletsWithoutSystem, AssetDeposit, Assets, Balances, ExistentialDeposit, ForeignAssets,
 	ForeignAssetsInstance, MetadataDepositBase, MetadataDepositPerByte, ParachainSystem, Runtime,
-	RuntimeCall, RuntimeEvent, SessionKeys, System, TrustBackedAssetsInstance,
+	RuntimeCall, RuntimeEvent, SessionKeys, System, TrustBackedAssetsInstance, XcmpQueue,
 };
 use asset_test_utils::{CollatorSessionKeys, ExtBuilder};
 use codec::{Decode, Encode};
@@ -657,3 +658,62 @@ asset_test_utils::include_create_and_manage_foreign_assets_for_local_consensus_p
 		assert_eq!(ForeignAssets::asset_ids().collect::<Vec<_>>().len(), 1);
 	})
 );
+
+#[test]
+fn reserve_transfer_native_asset_works() {
+	asset_test_utils::test_cases::reserve_transfer_native_asset_works::<
+		Runtime,
+		AllPalletsWithoutSystem,
+		XcmConfig,
+		ParachainSystem,
+		XcmpQueue,
+		LocationToAccountId,
+	>(
+		collator_session_keys(),
+		ExistentialDeposit::get(),
+		AccountId::from(ALICE),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::PolkadotXcm(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		WeightLimit::Unlimited,
+	);
+}
+
+#[test]
+fn reserve_withdraw_foreign_asset_works() {
+	asset_test_utils::test_cases::reserve_withdraw_foreign_asset_works::<
+		Runtime,
+		AllPalletsWithoutSystem,
+		XcmConfig,
+		ForeignAssetsInstance,
+		ParachainSystem,
+		XcmpQueue,
+		LocationToAccountId,
+	>(
+		collator_session_keys(),
+		ExistentialDeposit::get(),
+		AccountId::from(ALICE),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::PolkadotXcm(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		WeightLimit::Unlimited,
+	);
+}

cumulus/parachains/runtimes/assets/asset-hub-westend/src/weights/pallet_xcm.rs

@@ -92,6 +92,10 @@ impl<T: frame_system::Config> pallet_xcm::WeightInfo for WeightInfo<T> {
 			.saturating_add(Weight::from_parts(0, 1489))
 			.saturating_add(T::DbWeight::get().reads(1))
 	}
+	fn reserve_withdraw_assets() -> Weight {
+		Weight::from_parts(23_000_000, 0)
+			.saturating_add(Weight::from_parts(0, 0))
+	}
 	fn execute() -> Weight {
 		// Proof Size summary in bytes:
 		//  Measured:  `0`

cumulus/parachains/runtimes/assets/asset-hub-westend/tests/tests.rs

@@ -20,10 +20,10 @@
 use asset_hub_westend_runtime::{
 	xcm_config::{
 		AssetFeeAsExistentialDepositMultiplierFeeCharger, ForeignCreatorsSovereignAccountOf,
-		WestendLocation,
+		LocationToAccountId, WestendLocation,
 	},
 	AllPalletsWithoutSystem, MetadataDepositBase, MetadataDepositPerByte, RuntimeCall,
-	RuntimeEvent,
+	RuntimeEvent, XcmpQueue,
 };
 pub use asset_hub_westend_runtime::{
 	xcm_config::{CheckingAccount, TrustBackedAssetsPalletLocation, XcmConfig},
@@ -666,3 +666,62 @@ fn plain_receive_teleported_asset_works() {
 			assert_eq!(outcome.ensure_complete(), Ok(()));
 		})
 }
+
+#[test]
+fn reserve_transfer_native_asset_works() {
+	asset_test_utils::test_cases::reserve_transfer_native_asset_works::<
+		Runtime,
+		AllPalletsWithoutSystem,
+		XcmConfig,
+		ParachainSystem,
+		XcmpQueue,
+		LocationToAccountId,
+	>(
+		collator_session_keys(),
+		ExistentialDeposit::get(),
+		AccountId::from(ALICE),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::PolkadotXcm(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		WeightLimit::Unlimited,
+	);
+}
+
+#[test]
+fn reserve_withdraw_foreign_asset_works() {
+	asset_test_utils::test_cases::reserve_withdraw_foreign_asset_works::<
+		Runtime,
+		AllPalletsWithoutSystem,
+		XcmConfig,
+		ForeignAssetsInstance,
+		ParachainSystem,
+		XcmpQueue,
+		LocationToAccountId,
+	>(
+		collator_session_keys(),
+		ExistentialDeposit::get(),
+		AccountId::from(ALICE),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::PolkadotXcm(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
+				_ => None,
+			}
+		}),
+		WeightLimit::Unlimited,
+	);
+}

cumulus/parachains/runtimes/assets/test-utils/Cargo.toml

@@ -36,6 +36,7 @@ parachains-runtimes-test-utils = { path = "../../test-utils", default-features =
 
 # Polkadot
 xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false}
+xcm-builder = { package = "staging-xcm-builder", path = "../../../../../polkadot/xcm/xcm-builder", default-features = false}
 xcm-executor = { package = "staging-xcm-executor", path = "../../../../../polkadot/xcm/xcm-executor", default-features = false}
 pallet-xcm = { path = "../../../../../polkadot/xcm/pallet-xcm", default-features = false}
 polkadot-parachain-primitives = { path = "../../../../../polkadot/parachain", default-features = false}
@@ -72,6 +73,7 @@ std = [
 	"sp-io/std",
 	"sp-runtime/std",
 	"sp-std/std",
+	"xcm-builder/std",
 	"xcm-executor/std",
 	"xcm/std",
 ]

cumulus/parachains/runtimes/assets/test-utils/src/lib.rs

@@ -17,4 +17,79 @@
 //! Module contains predefined test-case scenarios for `Runtime` with various assets.
 
 pub mod test_cases;
+
+use frame_support::traits::ProcessMessageError;
 pub use parachains_runtimes_test_utils::*;
+
+use xcm::latest::prelude::*;
+use xcm_builder::{CreateMatcher, MatchXcm};
+
+/// Helper function to verify `xcm` contains all relevant instructions expected on destination
+/// chain as part of a reserve-asset-transfer.
+pub(crate) fn assert_matches_reserve_asset_deposited_instructions<RuntimeCall>(
+	xcm: &mut Xcm<RuntimeCall>,
+	expected_reserve_assets_deposited: &MultiAssets,
+	expected_beneficiary: &MultiLocation,
+) {
+	let _ = xcm
+		.0
+		.matcher()
+		.skip_inst_while(|inst| !matches!(inst, ReserveAssetDeposited(..)))
+		.expect("no instruction ReserveAssetDeposited?")
+		.match_next_inst(|instr| match instr {
+			ReserveAssetDeposited(reserve_assets)
+				if reserve_assets == expected_reserve_assets_deposited =>
+				Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction ReserveAssetDeposited")
+		.match_next_inst(|instr| match instr {
+			ClearOrigin => Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction ClearOrigin")
+		.match_next_inst(|instr| match instr {
+			BuyExecution { .. } => Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction BuyExecution")
+		.match_next_inst(|instr| match instr {
+			DepositAsset { assets: _, beneficiary } if beneficiary == expected_beneficiary =>
+				Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction DepositAsset");
+}
+
+/// Helper function to verify `xcm` contains all relevant instructions expected on destination
+/// chain as part of a reserve-asset-withdrawal.
+pub(crate) fn assert_matches_reserve_assets_withdrawal_instructions<RuntimeCall>(
+	xcm: &mut Xcm<RuntimeCall>,
+	expected_reserve_assets: &MultiAssets,
+	expected_beneficiary: &MultiLocation,
+) {
+	let _ = xcm
+		.0
+		.matcher()
+		.match_next_inst(|instr| match instr {
+			WithdrawAsset(reserve_assets) if reserve_assets == expected_reserve_assets => Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction WithdrawAsset for reserve asset")
+		.match_next_inst(|instr| match instr {
+			ClearOrigin => Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction ClearOrigin")
+		.match_next_inst(|instr| match instr {
+			BuyExecution { .. } => Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction BuyExecution")
+		.match_next_inst(|instr| match instr {
+			DepositAsset { assets: _, beneficiary } if beneficiary == expected_beneficiary =>
+				Ok(()),
+			_ => Err(ProcessMessageError::BadFormat),
+		})
+		.expect("expected instruction DepositAsset");
+}