pallet-xcm: enhance reserve_transfer_assets to support remote reserves (#1672)

## Motivation

`pallet-xcm` is the main user-facing interface for XCM functionality,
including assets manipulation functions like `teleportAssets()` and
`reserve_transfer_assets()` calls.

While `teleportAsset()` works both ways, `reserve_transfer_assets()`
works only for sending reserve-based assets to a remote destination and
beneficiary when the reserve is the _local chain_.

## Solution

This PR enhances `pallet_xcm::(limited_)reserve_withdraw_assets` to
support transfers when reserves are other chains.
This will allow complete, **bi-directional** reserve-based asset
transfers user stories using `pallet-xcm`.

Enables following scenarios:
- transferring assets with local reserve (was previously supported iff
asset used as fee also had local reserve - now it works in all cases),
- transferring assets with reserve on destination,
- transferring assets with reserve on remote/third-party chain (iff
assets and fees have same remote reserve),
- transferring assets with reserve different than the reserve of the
asset to be used as fees - meaning can be used to transfer random asset
with local/dest reserve while using DOT for fees on all involved chains,
even if DOT local/dest reserve doesn't match asset reserve,
- transferring assets with any type of local/dest reserve while using
fees which can be teleported between involved chains.

All of the above is done by pallet inner logic without the user having
to specify which scenario/reserves/teleports/etc. The correct scenario
and corresponding XCM programs are identified, and respectively, built
automatically based on runtime configuration of trusted teleporters and
trusted reserves.

#### Current limitations:
- while `fees` and "non-fee" `assets` CAN have different reserves (or
fees CAN be teleported), the remaining "non-fee" `assets` CANNOT, among
themselves, have different reserve locations (this is also implicitly
enforced by `MAX_ASSETS_FOR_TRANSFER=2`, but this can be safely
increased in the future).
- `fees` and "non-fee" `assets` CANNOT have **different remote**
reserves (this could also be supported in the future, but adds even more
complexity while possibly not being worth it - we'll see what the future
holds).

Fixes https://github.com/paritytech/polkadot-sdk/issues/1584
Fixes https://github.com/paritytech/polkadot-sdk/issues/2055

---------

Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>

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

@@ -962,7 +962,7 @@ mod benches {
 		[cumulus_pallet_xcmp_queue, XcmpQueue]
 		[cumulus_pallet_dmp_queue, DmpQueue]
 		// XCM
-		[pallet_xcm, PolkadotXcm]
+		[pallet_xcm, PalletXcmExtrinsiscsBenchmark::<Runtime>]
 		// NOTE: Make sure you point to the individual modules below.
 		[pallet_xcm_benchmarks::fungible, XcmBalances]
 		[pallet_xcm_benchmarks::generic, XcmGeneric]
@@ -1200,6 +1200,7 @@ impl_runtime_apis! {
 			use frame_support::traits::StorageInfoTrait;
 			use frame_system_benchmarking::Pallet as SystemBench;
 			use cumulus_pallet_session_benchmarking::Pallet as SessionBench;
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
 
 			// This is defined once again in dispatch_benchmark, because list_benchmarks!
 			// and add_benchmarks! are macros exported by define_benchmarks! macros and those types
@@ -1243,6 +1244,39 @@ impl_runtime_apis! {
 			use cumulus_pallet_session_benchmarking::Pallet as SessionBench;
 			impl cumulus_pallet_session_benchmarking::Config for Runtime {}
 
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
+			impl pallet_xcm::benchmarking::Config for Runtime {
+				fn reachable_dest() -> Option<MultiLocation> {
+					Some(Parent.into())
+				}
+
+				fn teleportable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// Relay/native token can be teleported between AH and Relay.
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						Parent.into(),
+					))
+				}
+
+				fn reserve_transferable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// AH can reserve transfer native token to some random parachain.
+					let random_para_id = 43211234;
+					ParachainSystem::open_outbound_hrmp_channel_for_benchmarks_or_tests(
+						random_para_id.into()
+					);
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						ParentThen(Parachain(random_para_id).into()).into(),
+					))
+				}
+			}
+
 			use xcm::latest::prelude::*;
 			use xcm_config::{KsmLocation, MaxAssetsIntoHolding};
 			use pallet_xcm_benchmarks::asset_instance_from;

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

@@ -552,11 +552,6 @@ pub type XcmRouter = WithUniqueTopic<(
 	XcmpQueue,
 )>;
 
-#[cfg(feature = "runtime-benchmarks")]
-parameter_types! {
-	pub ReachableDest: Option<MultiLocation> = Some(Parent.into());
-}
-
 impl pallet_xcm::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	// We want to disallow users sending (arbitrary) XCMs from this chain.
@@ -586,8 +581,6 @@ impl pallet_xcm::Config for Runtime {
 	type SovereignAccountOf = LocationToAccountId;
 	type MaxLockers = ConstU32<8>;
 	type WeightInfo = crate::weights::pallet_xcm::WeightInfo<Runtime>;
-	#[cfg(feature = "runtime-benchmarks")]
-	type ReachableDest = ReachableDest;
 	type AdminOrigin = EnsureRoot<AccountId>;
 	type MaxRemoteLockConsumers = ConstU32<0>;
 	type RemoteLockConsumerIdentifier = ();

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};
@@ -518,12 +519,6 @@ asset_test_utils::include_teleports_for_native_asset_works!(
 			_ => None,
 		}
 	}),
-	Box::new(|runtime_event_encoded: Vec<u8>| {
-		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
-			Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
-			_ => None,
-		}
-	}),
 	1000
 );
 
@@ -632,3 +627,32 @@ 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_to_non_teleport_para_works() {
+	asset_test_utils::test_cases::reserve_transfer_native_asset_to_non_teleport_para_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,
+	);
+}

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

@@ -868,7 +868,7 @@ mod benches {
 		[cumulus_pallet_xcmp_queue, XcmpQueue]
 		[cumulus_pallet_dmp_queue, DmpQueue]
 		// XCM
-		[pallet_xcm, PolkadotXcm]
+		[pallet_xcm, PalletXcmExtrinsiscsBenchmark::<Runtime>]
 		// NOTE: Make sure you point to the individual modules below.
 		[pallet_xcm_benchmarks::fungible, XcmBalances]
 		[pallet_xcm_benchmarks::generic, XcmGeneric]
@@ -1082,6 +1082,7 @@ impl_runtime_apis! {
 			use frame_support::traits::StorageInfoTrait;
 			use frame_system_benchmarking::Pallet as SystemBench;
 			use cumulus_pallet_session_benchmarking::Pallet as SessionBench;
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
 
 			// This is defined once again in dispatch_benchmark, because list_benchmarks!
 			// and add_benchmarks! are macros exported by define_benchmarks! macros and those types
@@ -1124,6 +1125,39 @@ impl_runtime_apis! {
 			use cumulus_pallet_session_benchmarking::Pallet as SessionBench;
 			impl cumulus_pallet_session_benchmarking::Config for Runtime {}
 
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
+			impl pallet_xcm::benchmarking::Config for Runtime {
+				fn reachable_dest() -> Option<MultiLocation> {
+					Some(Parent.into())
+				}
+
+				fn teleportable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// Relay/native token can be teleported between AH and Relay.
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						Parent.into(),
+					))
+				}
+
+				fn reserve_transferable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// AH can reserve transfer native token to some random parachain.
+					let random_para_id = 43211234;
+					ParachainSystem::open_outbound_hrmp_channel_for_benchmarks_or_tests(
+						random_para_id.into()
+					);
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						ParentThen(Parachain(random_para_id).into()).into(),
+					))
+				}
+			}
+
 			use xcm::latest::prelude::*;
 			use xcm_config::{DotLocation, MaxAssetsIntoHolding};
 			use pallet_xcm_benchmarks::asset_instance_from;

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

@@ -476,11 +476,6 @@ pub type XcmRouter = WithUniqueTopic<(
 	XcmpQueue,
 )>;
 
-#[cfg(feature = "runtime-benchmarks")]
-parameter_types! {
-	pub ReachableDest: Option<MultiLocation> = Some(Parent.into());
-}
-
 impl pallet_xcm::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	// We want to disallow users sending (arbitrary) XCMs from this chain.
@@ -510,8 +505,6 @@ impl pallet_xcm::Config for Runtime {
 	type SovereignAccountOf = LocationToAccountId;
 	type MaxLockers = ConstU32<8>;
 	type WeightInfo = crate::weights::pallet_xcm::WeightInfo<Runtime>;
-	#[cfg(feature = "runtime-benchmarks")]
-	type ReachableDest = ReachableDest;
 	type AdminOrigin = EnsureRoot<AccountId>;
 	type MaxRemoteLockConsumers = ConstU32<0>;
 	type RemoteLockConsumerIdentifier = ();

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};
@@ -531,12 +532,6 @@ asset_test_utils::include_teleports_for_native_asset_works!(
 			_ => None,
 		}
 	}),
-	Box::new(|runtime_event_encoded: Vec<u8>| {
-		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
-			Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
-			_ => None,
-		}
-	}),
 	1000
 );
 
@@ -657,3 +652,32 @@ 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_to_non_teleport_para_works() {
+	asset_test_utils::test_cases::reserve_transfer_native_asset_to_non_teleport_para_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,
+	);
+}

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs

@@ -1077,7 +1077,7 @@ mod benches {
 		[pallet_xcm_bridge_hub_router, ToWestend]
 		[pallet_xcm_bridge_hub_router, ToRococo]
 		// XCM
-		[pallet_xcm, PolkadotXcm]
+		[pallet_xcm, PalletXcmExtrinsiscsBenchmark::<Runtime>]
 		// NOTE: Make sure you point to the individual modules below.
 		[pallet_xcm_benchmarks::fungible, XcmBalances]
 		[pallet_xcm_benchmarks::generic, XcmGeneric]
@@ -1315,6 +1315,7 @@ impl_runtime_apis! {
 			use frame_support::traits::StorageInfoTrait;
 			use frame_system_benchmarking::Pallet as SystemBench;
 			use cumulus_pallet_session_benchmarking::Pallet as SessionBench;
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
 			use pallet_xcm_bridge_hub_router::benchmarking::Pallet as XcmBridgeHubRouterBench;
 
 			// This is defined once again in dispatch_benchmark, because list_benchmarks!
@@ -1368,6 +1369,39 @@ impl_runtime_apis! {
 				Config as XcmBridgeHubRouterConfig,
 			};
 
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
+			impl pallet_xcm::benchmarking::Config for Runtime {
+				fn reachable_dest() -> Option<MultiLocation> {
+					Some(Parent.into())
+				}
+
+				fn teleportable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// Relay/native token can be teleported between AH and Relay.
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						Parent.into(),
+					))
+				}
+
+				fn reserve_transferable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// AH can reserve transfer native token to some random parachain.
+					let random_para_id = 43211234;
+					ParachainSystem::open_outbound_hrmp_channel_for_benchmarks_or_tests(
+						random_para_id.into()
+					);
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						ParentThen(Parachain(random_para_id).into()).into(),
+					))
+				}
+			}
+
 			impl XcmBridgeHubRouterConfig<ToWococoXcmRouterInstance> for Runtime {
 				fn make_congested() {
 					cumulus_pallet_xcmp_queue::bridging::suspend_channel_for_benchmarks::<Runtime>(

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/xcm_config.rs

@@ -667,11 +667,6 @@ pub type XcmRouter = WithUniqueTopic<(
 	ToRococoXcmRouter,
 )>;
 
-#[cfg(feature = "runtime-benchmarks")]
-parameter_types! {
-	pub ReachableDest: Option<MultiLocation> = Some(Parent.into());
-}
-
 impl pallet_xcm::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	// We want to disallow users sending (arbitrary) XCMs from this chain.
@@ -701,8 +696,6 @@ impl pallet_xcm::Config for Runtime {
 	type SovereignAccountOf = LocationToAccountId;
 	type MaxLockers = ConstU32<8>;
 	type WeightInfo = crate::weights::pallet_xcm::WeightInfo<Runtime>;
-	#[cfg(feature = "runtime-benchmarks")]
-	type ReachableDest = ReachableDest;
 	type AdminOrigin = EnsureRoot<AccountId>;
 	type MaxRemoteLockConsumers = ConstU32<0>;
 	type RemoteLockConsumerIdentifier = ();

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

@@ -529,12 +529,6 @@ asset_test_utils::include_teleports_for_native_asset_works!(
 			_ => None,
 		}
 	}),
-	Box::new(|runtime_event_encoded: Vec<u8>| {
-		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
-			Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
-			_ => None,
-		}
-	}),
 	1000
 );
 
@@ -930,6 +924,35 @@ mod asset_hub_rococo_tests {
 			actual
 		);
 	}
+
+	#[test]
+	fn reserve_transfer_native_asset_to_non_teleport_para_works() {
+		asset_test_utils::test_cases::reserve_transfer_native_asset_to_non_teleport_para_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,
+		);
+	}
 }
 
 mod asset_hub_wococo_tests {

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

@@ -1013,7 +1013,7 @@ mod benches {
 		[cumulus_pallet_dmp_queue, DmpQueue]
 		[pallet_xcm_bridge_hub_router, ToRococo]
 		// XCM
-		[pallet_xcm, PolkadotXcm]
+		[pallet_xcm, PalletXcmExtrinsiscsBenchmark::<Runtime>]
 		// NOTE: Make sure you point to the individual modules below.
 		[pallet_xcm_benchmarks::fungible, XcmBalances]
 		[pallet_xcm_benchmarks::generic, XcmGeneric]
@@ -1297,6 +1297,7 @@ impl_runtime_apis! {
 			use frame_support::traits::StorageInfoTrait;
 			use frame_system_benchmarking::Pallet as SystemBench;
 			use cumulus_pallet_session_benchmarking::Pallet as SessionBench;
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
 			use pallet_xcm_bridge_hub_router::benchmarking::Pallet as XcmBridgeHubRouterBench;
 
 			// This is defined once again in dispatch_benchmark, because list_benchmarks!
@@ -1343,6 +1344,39 @@ impl_runtime_apis! {
 			use cumulus_pallet_session_benchmarking::Pallet as SessionBench;
 			impl cumulus_pallet_session_benchmarking::Config for Runtime {}
 
+			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsiscsBenchmark;
+			impl pallet_xcm::benchmarking::Config for Runtime {
+				fn reachable_dest() -> Option<MultiLocation> {
+					Some(Parent.into())
+				}
+
+				fn teleportable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// Relay/native token can be teleported between AH and Relay.
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						Parent.into(),
+					))
+				}
+
+				fn reserve_transferable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+					// AH can reserve transfer native token to some random parachain.
+					let random_para_id = 43211234;
+					ParachainSystem::open_outbound_hrmp_channel_for_benchmarks_or_tests(
+						random_para_id.into()
+					);
+					Some((
+						MultiAsset {
+							fun: Fungible(EXISTENTIAL_DEPOSIT),
+							id: Concrete(Parent.into())
+						},
+						ParentThen(Parachain(random_para_id).into()).into(),
+					))
+				}
+			}
+
 			use pallet_xcm_bridge_hub_router::benchmarking::{
 				Pallet as XcmBridgeHubRouterBench,
 				Config as XcmBridgeHubRouterConfig,

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

@@ -636,11 +636,6 @@ pub type XcmRouter = WithUniqueTopic<(
 	ToRococoXcmRouter,
 )>;
 
-#[cfg(feature = "runtime-benchmarks")]
-parameter_types! {
-	pub ReachableDest: Option<MultiLocation> = Some(Parent.into());
-}
-
 impl pallet_xcm::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type SendXcmOrigin = EnsureXcmOrigin<RuntimeOrigin, LocalOriginToLocation>;
@@ -666,8 +661,6 @@ impl pallet_xcm::Config for Runtime {
 	type SovereignAccountOf = LocationToAccountId;
 	type MaxLockers = ConstU32<8>;
 	type WeightInfo = crate::weights::pallet_xcm::WeightInfo<Runtime>;
-	#[cfg(feature = "runtime-benchmarks")]
-	type ReachableDest = ReachableDest;
 	type AdminOrigin = EnsureRoot<AccountId>;
 	type MaxRemoteLockConsumers = ConstU32<0>;
 	type RemoteLockConsumerIdentifier = ();

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

@@ -525,12 +525,6 @@ asset_test_utils::include_teleports_for_native_asset_works!(
 			_ => None,
 		}
 	}),
-	Box::new(|runtime_event_encoded: Vec<u8>| {
-		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
-			Ok(RuntimeEvent::XcmpQueue(event)) => Some(event),
-			_ => None,
-		}
-	}),
 	1000
 );
 
@@ -815,3 +809,32 @@ fn change_xcm_bridge_hub_router_byte_fee_by_governance_works() {
 		},
 	)
 }
+
+#[test]
+fn reserve_transfer_native_asset_to_non_teleport_para_works() {
+	asset_test_utils::test_cases::reserve_transfer_native_asset_to_non_teleport_para_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,
+	);
+}

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

@@ -27,6 +27,21 @@ use std::fmt::Debug;
 use xcm::latest::prelude::*;
 use xcm_builder::{CreateMatcher, MatchXcm};
 
+/// Given a message, a sender, and a destination, it returns the delivery fees
+fn get_fungible_delivery_fees<S: SendXcm>(destination: MultiLocation, message: Xcm<()>) -> u128 {
+	let Ok((_, delivery_fees)) = validate_send::<S>(destination, message) else {
+		unreachable!("message can be sent; qed")
+	};
+	if let Some(delivery_fee) = delivery_fees.inner().first() {
+		let Fungible(delivery_fee_amount) = delivery_fee.fun else {
+			unreachable!("asset is fungible; qed");
+		};
+		delivery_fee_amount
+	} else {
+		0
+	}
+}
+
 /// 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: Debug>(

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

@@ -16,25 +16,28 @@
 //! Module contains predefined test-case scenarios for `Runtime` with various assets.
 
 use super::xcm_helpers;
+use crate::{assert_matches_reserve_asset_deposited_instructions, get_fungible_delivery_fees};
 use codec::Encode;
+use cumulus_primitives_core::XcmpMessageSource;
 use frame_support::{
 	assert_noop, assert_ok,
 	traits::{
-		fungible::Mutate, fungibles::InspectEnumerable, Get, OnFinalize, OnInitialize, OriginTrait,
+		fungible::Mutate, fungibles::InspectEnumerable, Currency, Get, OnFinalize, OnInitialize,
+		OriginTrait,
 	},
 	weights::Weight,
 };
 use frame_system::pallet_prelude::BlockNumberFor;
 use parachains_common::{AccountId, Balance};
 use parachains_runtimes_test_utils::{
-	assert_metadata, assert_total, AccountIdOf, BalanceOf, CollatorSessionKeys, ExtBuilder,
-	ValidatorIdOf, XcmReceivedFrom,
+	assert_metadata, assert_total, mock_open_hrmp_channel, AccountIdOf, BalanceOf,
+	CollatorSessionKeys, ExtBuilder, ValidatorIdOf, XcmReceivedFrom,
 };
 use sp_runtime::{
 	traits::{MaybeEquivalence, StaticLookup, Zero},
 	DispatchError, Saturating,
 };
-use xcm::latest::prelude::*;
+use xcm::{latest::prelude::*, VersionedMultiAssets};
 use xcm_executor::{traits::ConvertLocation, XcmExecutor};
 
 type RuntimeHelper<Runtime, AllPalletsWithoutSystem = ()> =
@@ -43,8 +46,8 @@ type RuntimeHelper<Runtime, AllPalletsWithoutSystem = ()> =
 // Re-export test_case from `parachains-runtimes-test-utils`
 pub use parachains_runtimes_test_utils::test_cases::change_storage_constant_by_governance_works;
 
-/// Test-case makes sure that `Runtime` can receive native asset from relay chain
-/// and can teleport it back and to the other parachains
+/// Test-case makes sure that `Runtime` can receive native asset from relay chain and can teleport
+/// it back
 pub fn teleports_for_native_asset_works<
 	Runtime,
 	AllPalletsWithoutSystem,
@@ -57,9 +60,6 @@ pub fn teleports_for_native_asset_works<
 	existential_deposit: BalanceOf<Runtime>,
 	target_account: AccountIdOf<Runtime>,
 	unwrap_pallet_xcm_event: Box<dyn Fn(Vec<u8>) -> Option<pallet_xcm::Event<Runtime>>>,
-	unwrap_xcmp_queue_event: Box<
-		dyn Fn(Vec<u8>) -> Option<cumulus_pallet_xcmp_queue::Event<Runtime>>,
-	>,
 	runtime_para_id: u32,
 ) where
 	Runtime: frame_system::Config
@@ -164,12 +164,13 @@ pub fn teleports_for_native_asset_works<
 			// 2. try to teleport asset back to the relaychain
 			{
 				let dest = MultiLocation::parent();
-				let dest_beneficiary = MultiLocation::parent()
+				let mut dest_beneficiary = MultiLocation::parent()
 					.appended_with(AccountId32 {
 						network: None,
 						id: sp_runtime::AccountId32::new([3; 32]).into(),
 					})
 					.unwrap();
+				dest_beneficiary.reanchor(&dest, XcmConfig::UniversalLocation::get()).unwrap();
 
 				let target_account_balance_before_teleport =
 					<pallet_balances::Pallet<Runtime>>::free_balance(&target_account);
@@ -223,65 +224,53 @@ pub fn teleports_for_native_asset_works<
 				);
 			}
 
-			// 3. try to teleport asset away to other parachain (1234)
+			// 3. try to teleport assets away to other parachain (2345): should not work as we don't
+			//    trust `IsTeleporter` for `(relay-native-asset, para(2345))` pair
 			{
-				let other_para_id = 1234;
+				let other_para_id = 2345;
 				let dest = MultiLocation::new(1, X1(Parachain(other_para_id)));
-				let dest_beneficiary = MultiLocation::new(1, X1(Parachain(other_para_id)))
+				let mut dest_beneficiary = MultiLocation::new(1, X1(Parachain(other_para_id)))
 					.appended_with(AccountId32 {
 						network: None,
 						id: sp_runtime::AccountId32::new([3; 32]).into(),
 					})
 					.unwrap();
+				dest_beneficiary.reanchor(&dest, XcmConfig::UniversalLocation::get()).unwrap();
 
 				let target_account_balance_before_teleport =
 					<pallet_balances::Pallet<Runtime>>::free_balance(&target_account);
+
 				let native_asset_to_teleport_away = native_asset_amount_unit * 3.into();
 				assert!(
 					native_asset_to_teleport_away <
 						target_account_balance_before_teleport - existential_deposit
 				);
-
-				assert_ok!(RuntimeHelper::<Runtime>::do_teleport_assets::<HrmpChannelOpener>(
-					RuntimeHelper::<Runtime>::origin_of(target_account.clone()),
-					dest,
-					dest_beneficiary,
-					(native_asset_id, native_asset_to_teleport_away.into()),
-					Some((runtime_para_id, other_para_id)),
-					included_head,
-					&alice,
-				));
-
-				let delivery_fees =
-					xcm_helpers::transfer_assets_delivery_fees::<XcmConfig::XcmSender>(
-						(native_asset_id, native_asset_to_teleport_away.into()).into(),
-						0,
-						Unlimited,
-						dest_beneficiary,
+				assert_eq!(
+					RuntimeHelper::<Runtime>::do_teleport_assets::<HrmpChannelOpener>(
+						RuntimeHelper::<Runtime>::origin_of(target_account.clone()),
 						dest,
-					);
+						dest_beneficiary,
+						(native_asset_id, native_asset_to_teleport_away.into()),
+						Some((runtime_para_id, other_para_id)),
+						included_head,
+						&alice,
+					),
+					Err(DispatchError::Module(sp_runtime::ModuleError {
+						index: 31,
+						error: [2, 0, 0, 0,],
+						message: Some("Filtered",),
+					},),)
+				);
 
 				// check balances
 				assert_eq!(
 					<pallet_balances::Pallet<Runtime>>::free_balance(&target_account),
-					target_account_balance_before_teleport -
-						native_asset_to_teleport_away -
-						delivery_fees.into()
+					target_account_balance_before_teleport
 				);
 				assert_eq!(
 					<pallet_balances::Pallet<Runtime>>::free_balance(&CheckingAccount::get()),
 					0.into()
 				);
-
-				// check events
-				RuntimeHelper::<Runtime>::assert_pallet_xcm_event_outcome(
-					&unwrap_pallet_xcm_event,
-					|outcome| {
-						assert_ok!(outcome.ensure_complete());
-					},
-				);
-				assert!(RuntimeHelper::<Runtime>::xcmp_queue_message_sent(unwrap_xcmp_queue_event)
-					.is_some());
 			}
 		})
 }
@@ -298,7 +287,6 @@ macro_rules! include_teleports_for_native_asset_works(
 		$collator_session_key:expr,
 		$existential_deposit:expr,
 		$unwrap_pallet_xcm_event:expr,
-		$unwrap_xcmp_queue_event:expr,
 		$runtime_para_id:expr
 	) => {
 		#[test]
@@ -318,15 +306,14 @@ macro_rules! include_teleports_for_native_asset_works(
 				$existential_deposit,
 				target_account,
 				$unwrap_pallet_xcm_event,
-				$unwrap_xcmp_queue_event,
 				$runtime_para_id
 			)
 		}
 	}
 );
 
-/// Test-case makes sure that `Runtime` can receive teleported assets from sibling parachain relay
-/// chain
+/// Test-case makes sure that `Runtime` can receive teleported assets from sibling parachain, and
+/// can teleport it back
 pub fn teleports_for_foreign_assets_works<
 	Runtime,
 	AllPalletsWithoutSystem,
@@ -381,7 +368,7 @@ pub fn teleports_for_foreign_assets_works<
 	<Runtime as frame_system::Config>::AccountId: From<AccountId>,
 	ForeignAssetsPalletInstance: 'static,
 {
-	// foreign parachain with the same consenus currency as asset
+	// foreign parachain with the same consensus currency as asset
 	let foreign_para_id = 2222;
 	let foreign_asset_id_multilocation = MultiLocation {
 		parents: 1,
@@ -473,7 +460,7 @@ pub fn teleports_for_foreign_assets_works<
 			>(foreign_asset_id_multilocation, 0, 0);
 			assert!(teleported_foreign_asset_amount > asset_minimum_asset_balance);
 
-			// 1. process received teleported assets from relaychain
+			// 1. process received teleported assets from sibling parachain (foreign_para_id)
 			let xcm = Xcm(vec![
 				// BuyExecution with relaychain native token
 				WithdrawAsset(buy_execution_fee.clone().into()),
@@ -551,12 +538,13 @@ pub fn teleports_for_foreign_assets_works<
 			// 2. try to teleport asset back to source parachain (foreign_para_id)
 			{
 				let dest = MultiLocation::new(1, X1(Parachain(foreign_para_id)));
-				let dest_beneficiary = MultiLocation::new(1, X1(Parachain(foreign_para_id)))
+				let mut dest_beneficiary = MultiLocation::new(1, X1(Parachain(foreign_para_id)))
 					.appended_with(AccountId32 {
 						network: None,
 						id: sp_runtime::AccountId32::new([3; 32]).into(),
 					})
 					.unwrap();
+				dest_beneficiary.reanchor(&dest, XcmConfig::UniversalLocation::get()).unwrap();
 
 				let target_account_balance_before_teleport =
 					<pallet_assets::Pallet<Runtime, ForeignAssetsPalletInstance>>::balance(
@@ -1108,7 +1096,7 @@ pub fn create_and_manage_foreign_assets_for_local_consensus_parachain_assets_wor
 	AssetId: Clone + Copy,
 	AssetIdConverter: MaybeEquivalence<MultiLocation, AssetId>,
 {
-	// foreign parachain with the same consenus currency as asset
+	// foreign parachain with the same consensus currency as asset
 	let foreign_asset_id_multilocation =
 		MultiLocation { parents: 1, interior: X2(Parachain(2222), GeneralIndex(1234567)) };
 	let asset_id = AssetIdConverter::convert(&foreign_asset_id_multilocation).unwrap();
@@ -1388,3 +1376,199 @@ macro_rules! include_create_and_manage_foreign_assets_for_local_consensus_parach
 		}
 	}
 );
+
+/// Test-case makes sure that `Runtime` can reserve-transfer asset to other parachains (where
+/// teleport is not trusted)
+pub fn reserve_transfer_native_asset_to_non_teleport_para_works<
+	Runtime,
+	AllPalletsWithoutSystem,
+	XcmConfig,
+	HrmpChannelOpener,
+	HrmpChannelSource,
+	LocationToAccountId,
+>(
+	collator_session_keys: CollatorSessionKeys<Runtime>,
+	existential_deposit: BalanceOf<Runtime>,
+	alice_account: AccountIdOf<Runtime>,
+	unwrap_pallet_xcm_event: Box<dyn Fn(Vec<u8>) -> Option<pallet_xcm::Event<Runtime>>>,
+	unwrap_xcmp_queue_event: Box<
+		dyn Fn(Vec<u8>) -> Option<cumulus_pallet_xcmp_queue::Event<Runtime>>,
+	>,
+	weight_limit: WeightLimit,
+) where
+	Runtime: frame_system::Config
+		+ pallet_balances::Config
+		+ pallet_session::Config
+		+ pallet_xcm::Config
+		+ parachain_info::Config
+		+ pallet_collator_selection::Config
+		+ cumulus_pallet_parachain_system::Config
+		+ cumulus_pallet_xcmp_queue::Config,
+	AllPalletsWithoutSystem:
+		OnInitialize<BlockNumberFor<Runtime>> + OnFinalize<BlockNumberFor<Runtime>>,
+	AccountIdOf<Runtime>: Into<[u8; 32]>,
+	ValidatorIdOf<Runtime>: From<AccountIdOf<Runtime>>,
+	BalanceOf<Runtime>: From<Balance>,
+	<Runtime as pallet_balances::Config>::Balance: From<Balance> + Into<u128>,
+	XcmConfig: xcm_executor::Config,
+	LocationToAccountId: ConvertLocation<AccountIdOf<Runtime>>,
+	<Runtime as frame_system::Config>::AccountId:
+		Into<<<Runtime as frame_system::Config>::RuntimeOrigin as OriginTrait>::AccountId>,
+	<<Runtime as frame_system::Config>::Lookup as StaticLookup>::Source:
+		From<<Runtime as frame_system::Config>::AccountId>,
+	<Runtime as frame_system::Config>::AccountId: From<AccountId>,
+	HrmpChannelOpener: frame_support::inherent::ProvideInherent<
+		Call = cumulus_pallet_parachain_system::Call<Runtime>,
+	>,
+	HrmpChannelSource: XcmpMessageSource,
+{
+	let runtime_para_id = 1000;
+	ExtBuilder::<Runtime>::default()
+		.with_collators(collator_session_keys.collators())
+		.with_session_keys(collator_session_keys.session_keys())
+		.with_tracing()
+		.with_safe_xcm_version(3)
+		.with_para_id(runtime_para_id.into())
+		.build()
+		.execute_with(|| {
+			let mut alice = [0u8; 32];
+			alice[0] = 1;
+			let included_head = RuntimeHelper::<Runtime, AllPalletsWithoutSystem>::run_to_block(
+				2,
+				AccountId::from(alice).into(),
+			);
+
+			// reserve-transfer native asset with local reserve to remote parachain (2345)
+
+			let other_para_id = 2345;
+			let native_asset = MultiLocation::parent();
+			let dest = MultiLocation::new(1, X1(Parachain(other_para_id)));
+			let mut dest_beneficiary = MultiLocation::new(1, X1(Parachain(other_para_id)))
+				.appended_with(AccountId32 {
+					network: None,
+					id: sp_runtime::AccountId32::new([3; 32]).into(),
+				})
+				.unwrap();
+			dest_beneficiary.reanchor(&dest, XcmConfig::UniversalLocation::get()).unwrap();
+
+			let reserve_account = LocationToAccountId::convert_location(&dest)
+				.expect("Sovereign account for reserves");
+			let balance_to_transfer = 1_000_000_000_000_u128;
+
+			// open HRMP to other parachain
+			mock_open_hrmp_channel::<Runtime, HrmpChannelOpener>(
+				runtime_para_id.into(),
+				other_para_id.into(),
+				included_head,
+				&alice,
+			);
+
+			// we calculate exact delivery fees _after_ sending the message by weighing the sent
+			// xcm, and this delivery fee varies for different runtimes, so just add enough buffer,
+			// then verify the arithmetics check out on final balance.
+			let delivery_fees_buffer = 40_000_000_000u128;
+			// drip 2xED + transfer_amount + delivery_fees_buffer to Alice account
+			let alice_account_init_balance = existential_deposit.saturating_mul(2.into()) +
+				balance_to_transfer.into() +
+				delivery_fees_buffer.into();
+			let _ = <pallet_balances::Pallet<Runtime>>::deposit_creating(
+				&alice_account,
+				alice_account_init_balance,
+			);
+			// SA of target location needs to have at least ED, otherwise making reserve fails
+			let _ = <pallet_balances::Pallet<Runtime>>::deposit_creating(
+				&reserve_account,
+				existential_deposit,
+			);
+
+			// we just check here, that user retains enough balance after withdrawal
+			// and also we check if `balance_to_transfer` is more than `existential_deposit`,
+			assert!(
+				(<pallet_balances::Pallet<Runtime>>::free_balance(&alice_account) -
+					balance_to_transfer.into()) >=
+					existential_deposit
+			);
+			// SA has just ED
+			assert_eq!(
+				<pallet_balances::Pallet<Runtime>>::free_balance(&reserve_account),
+				existential_deposit
+			);
+
+			// local native asset (pallet_balances)
+			let asset_to_transfer = MultiAsset {
+				fun: Fungible(balance_to_transfer.into()),
+				id: Concrete(native_asset),
+			};
+
+			// pallet_xcm call reserve transfer
+			assert_ok!(<pallet_xcm::Pallet<Runtime>>::limited_reserve_transfer_assets(
+				RuntimeHelper::<Runtime, AllPalletsWithoutSystem>::origin_of(alice_account.clone()),
+				Box::new(dest.into_versioned()),
+				Box::new(dest_beneficiary.into_versioned()),
+				Box::new(VersionedMultiAssets::from(MultiAssets::from(asset_to_transfer))),
+				0,
+				weight_limit,
+			));
+
+			// check events
+			// check pallet_xcm attempted
+			RuntimeHelper::<Runtime, AllPalletsWithoutSystem>::assert_pallet_xcm_event_outcome(
+				&unwrap_pallet_xcm_event,
+				|outcome| {
+					assert_ok!(outcome.ensure_complete());
+				},
+			);
+
+			// check that xcm was sent
+			let xcm_sent_message_hash = <frame_system::Pallet<Runtime>>::events()
+				.into_iter()
+				.filter_map(|e| unwrap_xcmp_queue_event(e.event.encode()))
+				.find_map(|e| match e {
+					cumulus_pallet_xcmp_queue::Event::XcmpMessageSent { message_hash } =>
+						Some(message_hash),
+					_ => None,
+				});
+
+			// read xcm
+			let xcm_sent = RuntimeHelper::<HrmpChannelSource, AllPalletsWithoutSystem>::take_xcm(
+				other_para_id.into(),
+			)
+			.unwrap();
+
+			let delivery_fees = get_fungible_delivery_fees::<
+				<XcmConfig as xcm_executor::Config>::XcmSender,
+			>(dest, Xcm::try_from(xcm_sent.clone()).unwrap());
+
+			assert_eq!(
+				xcm_sent_message_hash,
+				Some(xcm_sent.using_encoded(sp_io::hashing::blake2_256))
+			);
+			let mut xcm_sent: Xcm<()> = xcm_sent.try_into().expect("versioned xcm");
+
+			// check sent XCM Program to other parachain
+			println!("reserve_transfer_native_asset_works sent xcm: {:?}", xcm_sent);
+			let reserve_assets_deposited = MultiAssets::from(vec![MultiAsset {
+				id: Concrete(MultiLocation { parents: 1, interior: Here }),
+				fun: Fungible(1000000000000),
+			}]);
+
+			assert_matches_reserve_asset_deposited_instructions(
+				&mut xcm_sent,
+				&reserve_assets_deposited,
+				&dest_beneficiary,
+			);
+
+			// check alice account decreased by balance_to_transfer ( + delivery_fees)
+			assert_eq!(
+				<pallet_balances::Pallet<Runtime>>::free_balance(&alice_account),
+				alice_account_init_balance - balance_to_transfer.into() - delivery_fees.into()
+			);
+
+			// check reserve account
+			// check reserve account increased by balance_to_transfer
+			assert_eq!(
+				<pallet_balances::Pallet<Runtime>>::free_balance(&reserve_account),
+				existential_deposit + balance_to_transfer.into()
+			);
+		})
+}

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

@@ -16,7 +16,7 @@
 //! Module contains predefined test-case scenarios for `Runtime` with various assets transferred
 //! over a bridge.
 
-use crate::assert_matches_reserve_asset_deposited_instructions;
+use crate::{assert_matches_reserve_asset_deposited_instructions, get_fungible_delivery_fees};
 use codec::Encode;
 use cumulus_primitives_core::XcmpMessageSource;
 use frame_support::{
@@ -32,10 +32,7 @@ use parachains_runtimes_test_utils::{
 use sp_runtime::{traits::StaticLookup, Saturating};
 use xcm::{latest::prelude::*, VersionedMultiAssets};
 use xcm_builder::{CreateMatcher, MatchXcm};
-use xcm_executor::{
-	traits::{ConvertLocation, TransactAsset},
-	XcmExecutor,
-};
+use xcm_executor::{traits::ConvertLocation, XcmExecutor};
 
 pub struct TestBridgingConfig {
 	pub bridged_network: NetworkId,
@@ -129,8 +126,13 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 				&alice,
 			);
 
-			// drip ED to account
-			let alice_account_init_balance = existential_deposit + balance_to_transfer.into();
+			// we calculate exact delivery fees _after_ sending the message by weighing the sent
+			// xcm, and this delivery fee varies for different runtimes, so just add enough buffer,
+			// then verify the arithmetics check out on final balance.
+			let delivery_fees_buffer = 8_000_000_000_000u128;
+			// drip ED + transfer_amount + delivery_fees_buffer to Alice account
+			let alice_account_init_balance =
+				existential_deposit + balance_to_transfer.into() + delivery_fees_buffer.into();
 			let _ = <pallet_balances::Pallet<Runtime>>::deposit_creating(
 				&alice_account,
 				alice_account_init_balance,
@@ -183,56 +185,6 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 
 			let expected_beneficiary = target_destination_account;
 
-			// Make sure sender has enough funds for paying delivery fees
-			let handling_delivery_fees = {
-				// Probable XCM with `ReserveAssetDeposited`.
-				let mut expected_reserve_asset_deposited_message = Xcm(vec![
-					ReserveAssetDeposited(MultiAssets::from(expected_assets.clone())),
-					ClearOrigin,
-					BuyExecution {
-						fees: MultiAsset {
-							id: Concrete(Default::default()),
-							fun: Fungible(balance_to_transfer),
-						},
-						weight_limit: Unlimited,
-					},
-					DepositAsset { assets: Wild(AllCounted(1)), beneficiary: expected_beneficiary },
-					SetTopic([
-						220, 188, 144, 32, 213, 83, 111, 175, 44, 210, 111, 19, 90, 165, 191, 112,
-						140, 247, 192, 124, 42, 17, 153, 141, 114, 34, 189, 20, 83, 69, 237, 173,
-					]),
-				]);
-				assert_matches_reserve_asset_deposited_instructions(
-					&mut expected_reserve_asset_deposited_message,
-					&expected_assets,
-					&expected_beneficiary,
-				);
-
-				// Call `SendXcm::validate` to get delivery fees.
-				let (_, delivery_fees): (_, MultiAssets) = XcmConfig::XcmSender::validate(
-					&mut Some(target_location_from_different_consensus),
-					&mut Some(expected_reserve_asset_deposited_message),
-				)
-				.expect("validate passes");
-				// Drip delivery fee to Alice account.
-				let mut delivery_fees_added = false;
-				for delivery_fee in delivery_fees.inner() {
-					assert_ok!(<XcmConfig::AssetTransactor as TransactAsset>::deposit_asset(
-						&delivery_fee,
-						&MultiLocation {
-							parents: 0,
-							interior: X1(AccountId32 {
-								network: None,
-								id: alice_account.clone().into(),
-							}),
-						},
-						None,
-					));
-					delivery_fees_added = true;
-				}
-				delivery_fees_added
-			};
-
 			// do pallet_xcm call reserve transfer
 			assert_ok!(<pallet_xcm::Pallet<Runtime>>::limited_reserve_transfer_assets(
 				RuntimeHelper::<Runtime, AllPalletsWithoutSystem>::origin_of(alice_account.clone()),
@@ -275,6 +227,7 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 
 			// check sent XCM ExportMessage to BridgeHub
 
+			let mut delivery_fees = 0;
 			// 1. check paid or unpaid
 			if let Some(expected_fee_asset_id) = maybe_paid_export_message {
 				xcm_sent
@@ -315,6 +268,10 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 							.split_global()
 							.expect("split works");
 					assert_eq!(destination, &target_location_junctions_without_global_consensus);
+					// Call `SendXcm::validate` to get delivery fees.
+					delivery_fees = get_fungible_delivery_fees::<
+						<XcmConfig as xcm_executor::Config>::XcmSender,
+					>(target_location_from_different_consensus, inner_xcm.clone());
 					assert_matches_reserve_asset_deposited_instructions(
 						inner_xcm,
 						&expected_assets,
@@ -330,8 +287,8 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 			assert_eq!(
 				<pallet_balances::Pallet<Runtime>>::free_balance(&alice_account),
 				alice_account_init_balance
-					.saturating_sub(existential_deposit)
 					.saturating_sub(balance_to_transfer.into())
+					.saturating_sub(delivery_fees.into())
 			);
 
 			// check reserve account increased by balance_to_transfer
@@ -341,14 +298,13 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 			);
 
 			// check dedicated account increased by delivery fees (if configured)
-			if handling_delivery_fees {
-				if let Some(delivery_fees_account) = delivery_fees_account {
-					let delivery_fees_account_balance_after =
-						<pallet_balances::Pallet<Runtime>>::free_balance(&delivery_fees_account);
-					assert!(
-						delivery_fees_account_balance_after > delivery_fees_account_balance_before
-					);
-				}
+			if let Some(delivery_fees_account) = delivery_fees_account {
+				let delivery_fees_account_balance_after =
+					<pallet_balances::Pallet<Runtime>>::free_balance(&delivery_fees_account);
+				assert!(
+					delivery_fees_account_balance_after - delivery_fees.into() >=
+						delivery_fees_account_balance_before
+				);
 			}
 		})
 }