Fix XcmPaymentApi::query_weight_to_asset_fee version conversion (#6459)

The `query_weight_to_asset_fee` function was trying to convert versions
by using `try_as`, this function [doesn't convert from a versioned to a
concrete
type](https://github.com/paritytech/polkadot-sdk/blob/0156ca8f959d5cf3787c18113ce48acaaf1a8345/polkadot/xcm/src/lib.rs#L131).
This would cause all calls with a lower version to fail.

The correct function to use is the good old
[try_into](https://github.com/paritytech/polkadot-sdk/blob/0156ca8f959d5cf3787c18113ce48acaaf1a8345/polkadot/xcm/src/lib.rs#L184).
Now those calls work :)

---------

Co-authored-by: command-bot <>
Co-authored-by: Branislav Kontur <[email protected]>
Co-authored-by: GitHub Action <[email protected]>

Author: 3 people

Cargo.lock

@@ -99,6 +99,7 @@ snowbridge-router-primitives = { workspace = true }
 
 [dev-dependencies]
 asset-test-utils = { workspace = true, default-features = true }
+parachains-runtimes-test-utils = { workspace = true, default-features = true }
 
 [build-dependencies]
 substrate-wasm-builder = { optional = true, workspace = true, default-features = true }

cumulus/parachains/runtimes/assets/asset-hub-rococo/Cargo.toml

@@ -1415,37 +1415,31 @@ impl_runtime_apis! {
 			// We accept the native token to pay fees.
 			let mut acceptable_assets = vec![AssetId(native_token.clone())];
 			// We also accept all assets in a pool with the native token.
-			let assets_in_pool_with_native = assets_common::get_assets_in_pool_with::<
-				Runtime,
-				xcm::v5::Location
-			>(&native_token).map_err(|()| XcmPaymentApiError::VersionedConversionFailed)?.into_iter();
-			acceptable_assets.extend(assets_in_pool_with_native);
+			acceptable_assets.extend(
+				assets_common::PoolAdapter::<Runtime>::get_assets_in_pool_with(native_token)
+				.map_err(|()| XcmPaymentApiError::VersionedConversionFailed)?
+			);
 			PolkadotXcm::query_acceptable_payment_assets(xcm_version, acceptable_assets)
 		}
 
 		fn query_weight_to_asset_fee(weight: Weight, asset: VersionedAssetId) -> Result<u128, XcmPaymentApiError> {
 			let native_asset = xcm_config::TokenLocation::get();
 			let fee_in_native = WeightToFee::weight_to_fee(&weight);
-			match asset.try_as::<AssetId>() {
+			let latest_asset_id: Result<AssetId, ()> = asset.clone().try_into();
+			match latest_asset_id {
 				Ok(asset_id) if asset_id.0 == native_asset => {
 					// for native token
 					Ok(fee_in_native)
 				},
 				Ok(asset_id) => {
-					let assets_in_pool_with_this_asset: Vec<_> = assets_common::get_assets_in_pool_with::<
-						Runtime,
-						xcm::v5::Location
-					>(&asset_id.0).map_err(|()| XcmPaymentApiError::VersionedConversionFailed)?;
-					if assets_in_pool_with_this_asset
-						.into_iter()
-						.map(|asset_id| asset_id.0)
-						.any(|location| location == native_asset) {
-						pallet_asset_conversion::Pallet::<Runtime>::quote_price_tokens_for_exact_tokens(
-							asset_id.clone().0,
+					// Try to get current price of `asset_id` in `native_asset`.
+					if let Ok(Some(swapped_in_native)) = assets_common::PoolAdapter::<Runtime>::quote_price_tokens_for_exact_tokens(
+							asset_id.0.clone(),
 							native_asset,
 							fee_in_native,
 							true, // We include the fee.
-						).ok_or(XcmPaymentApiError::AssetNotFound)
+						) {
+						Ok(swapped_in_native)
 					} else {
 						log::trace!(target: "xcm::xcm_runtime_apis", "query_weight_to_asset_fee - unhandled asset_id: {asset_id:?}!");
 						Err(XcmPaymentApiError::AssetNotFound)

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

@@ -24,10 +24,10 @@ use asset_hub_rococo_runtime::{
 		ForeignAssetFeeAsExistentialDepositMultiplierFeeCharger, LocationToAccountId, StakingPot,
 		TokenLocation, TrustBackedAssetsPalletLocation, XcmConfig,
 	},
-	AllPalletsWithoutSystem, AssetConversion, AssetDeposit, Assets, Balances, CollatorSelection,
-	ExistentialDeposit, ForeignAssets, ForeignAssetsInstance, MetadataDepositBase,
-	MetadataDepositPerByte, ParachainSystem, Runtime, RuntimeCall, RuntimeEvent, RuntimeOrigin,
-	SessionKeys, TrustBackedAssetsInstance, XcmpQueue,
+	AllPalletsWithoutSystem, AssetConversion, AssetDeposit, Assets, Balances, Block,
+	CollatorSelection, ExistentialDeposit, ForeignAssets, ForeignAssetsInstance,
+	MetadataDepositBase, MetadataDepositPerByte, ParachainSystem, Runtime, RuntimeCall,
+	RuntimeEvent, RuntimeOrigin, SessionKeys, TrustBackedAssetsInstance, XcmpQueue,
 };
 use asset_test_utils::{
 	test_cases_over_bridge::TestBridgingConfig, CollatorSessionKey, CollatorSessionKeys,
@@ -1471,3 +1471,19 @@ fn location_conversion_works() {
 		assert_eq!(got, expected, "{}", tc.description);
 	}
 }
+
+#[test]
+fn xcm_payment_api_works() {
+	parachains_runtimes_test_utils::test_cases::xcm_payment_api_with_native_token_works::<
+		Runtime,
+		RuntimeCall,
+		RuntimeOrigin,
+		Block,
+	>();
+	asset_test_utils::test_cases::xcm_payment_api_with_pools_works::<
+		Runtime,
+		RuntimeCall,
+		RuntimeOrigin,
+		Block,
+	>();
+}

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

@@ -101,6 +101,7 @@ snowbridge-router-primitives = { workspace = true }
 
 [dev-dependencies]
 asset-test-utils = { workspace = true, default-features = true }
+parachains-runtimes-test-utils = { workspace = true, default-features = true }
 
 [build-dependencies]
 substrate-wasm-builder = { optional = true, workspace = true, default-features = true }

cumulus/parachains/runtimes/assets/asset-hub-westend/Cargo.toml

@@ -1528,38 +1528,31 @@ impl_runtime_apis! {
 			// We accept the native token to pay fees.
 			let mut acceptable_assets = vec![AssetId(native_token.clone())];
 			// We also accept all assets in a pool with the native token.
-			let assets_in_pool_with_native = assets_common::get_assets_in_pool_with::<
-				Runtime,
-				xcm::v5::Location
-			>(&native_token).map_err(|()| XcmPaymentApiError::VersionedConversionFailed)?.into_iter();
-			acceptable_assets.extend(assets_in_pool_with_native);
+			acceptable_assets.extend(
+				assets_common::PoolAdapter::<Runtime>::get_assets_in_pool_with(native_token)
+				.map_err(|()| XcmPaymentApiError::VersionedConversionFailed)?
+			);
 			PolkadotXcm::query_acceptable_payment_assets(xcm_version, acceptable_assets)
 		}
 
 		fn query_weight_to_asset_fee(weight: Weight, asset: VersionedAssetId) -> Result<u128, XcmPaymentApiError> {
 			let native_asset = xcm_config::WestendLocation::get();
 			let fee_in_native = WeightToFee::weight_to_fee(&weight);
-			match asset.try_as::<AssetId>() {
+			let latest_asset_id: Result<AssetId, ()> = asset.clone().try_into();
+			match latest_asset_id {
 				Ok(asset_id) if asset_id.0 == native_asset => {
 					// for native asset
 					Ok(fee_in_native)
 				},
 				Ok(asset_id) => {
-					// We recognize assets in a pool with the native one.
-					let assets_in_pool_with_this_asset: Vec<_> = assets_common::get_assets_in_pool_with::<
-						Runtime,
-						xcm::v5::Location
-					>(&asset_id.0).map_err(|()| XcmPaymentApiError::VersionedConversionFailed)?;
-					if assets_in_pool_with_this_asset
-						.into_iter()
-						.map(|asset_id| asset_id.0)
-						.any(|location| location == native_asset) {
-						pallet_asset_conversion::Pallet::<Runtime>::quote_price_tokens_for_exact_tokens(
-							asset_id.clone().0,
+					// Try to get current price of `asset_id` in `native_asset`.
+					if let Ok(Some(swapped_in_native)) = assets_common::PoolAdapter::<Runtime>::quote_price_tokens_for_exact_tokens(
+							asset_id.0.clone(),
 							native_asset,
 							fee_in_native,
 							true, // We include the fee.
-						).ok_or(XcmPaymentApiError::AssetNotFound)
+						) {
+						Ok(swapped_in_native)
 					} else {
 						log::trace!(target: "xcm::xcm_runtime_apis", "query_weight_to_asset_fee - unhandled asset_id: {asset_id:?}!");
 						Err(XcmPaymentApiError::AssetNotFound)

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

@@ -24,7 +24,7 @@ use asset_hub_westend_runtime::{
 		ForeignAssetFeeAsExistentialDepositMultiplierFeeCharger, LocationToAccountId, StakingPot,
 		TrustBackedAssetsPalletLocation, WestendLocation, XcmConfig,
 	},
-	AllPalletsWithoutSystem, Assets, Balances, ExistentialDeposit, ForeignAssets,
+	AllPalletsWithoutSystem, Assets, Balances, Block, ExistentialDeposit, ForeignAssets,
 	ForeignAssetsInstance, MetadataDepositBase, MetadataDepositPerByte, ParachainSystem,
 	PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent, RuntimeOrigin, SessionKeys,
 	TrustBackedAssetsInstance, XcmpQueue,
@@ -1446,3 +1446,19 @@ fn location_conversion_works() {
 		assert_eq!(got, expected, "{}", tc.description);
 	}
 }
+
+#[test]
+fn xcm_payment_api_works() {
+	parachains_runtimes_test_utils::test_cases::xcm_payment_api_with_native_token_works::<
+		Runtime,
+		RuntimeCall,
+		RuntimeOrigin,
+		Block,
+	>();
+	asset_test_utils::test_cases::xcm_payment_api_with_pools_works::<
+		Runtime,
+		RuntimeCall,
+		RuntimeOrigin,
+		Block,
+	>();
+}

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

@@ -28,7 +28,7 @@ extern crate alloc;
 use crate::matching::{LocalLocationPattern, ParentLocation};
 use alloc::vec::Vec;
 use codec::{Decode, EncodeLike};
-use core::cmp::PartialEq;
+use core::{cmp::PartialEq, marker::PhantomData};
 use frame_support::traits::{Equals, EverythingBut};
 use parachains_common::{AssetIdForTrustBackedAssets, CollectionId, ItemId};
 use sp_runtime::traits::TryConvertInto;
@@ -137,24 +137,62 @@ pub type PoolAssetsConvertedConcreteId<PoolAssetsPalletLocation, Balance> =
 		TryConvertInto,
 	>;
 
-/// Returns an iterator of all assets in a pool with `asset`.
-///
-/// Should only be used in runtime APIs since it iterates over the whole
-/// `pallet_asset_conversion::Pools` map.
-///
-/// It takes in any version of an XCM Location but always returns the latest one.
-/// This is to allow some margin of migrating the pools when updating the XCM version.
-///
-/// An error of type `()` is returned if the version conversion fails for XCM locations.
-/// This error should be mapped by the caller to a more descriptive one.
-pub fn get_assets_in_pool_with<
-	Runtime: pallet_asset_conversion::Config<PoolId = (L, L)>,
-	L: TryInto<Location> + Clone + Decode + EncodeLike + PartialEq,
->(
-	asset: &L,
-) -> Result<Vec<AssetId>, ()> {
-	pallet_asset_conversion::Pools::<Runtime>::iter_keys()
-		.filter_map(|(asset_1, asset_2)| {
+/// Adapter implementation for accessing pools (`pallet_asset_conversion`) that uses `AssetKind` as
+/// a `xcm::v*` which could be different from the `xcm::latest`.
+pub struct PoolAdapter<Runtime>(PhantomData<Runtime>);
+impl<
+		Runtime: pallet_asset_conversion::Config<PoolId = (L, L), AssetKind = L>,
+		L: TryFrom<Location> + TryInto<Location> + Clone + Decode + EncodeLike + PartialEq,
+	> PoolAdapter<Runtime>
+{
+	/// Returns a vector of all assets in a pool with `asset`.
+	///
+	/// Should only be used in runtime APIs since it iterates over the whole
+	/// `pallet_asset_conversion::Pools` map.
+	///
+	/// It takes in any version of an XCM Location but always returns the latest one.
+	/// This is to allow some margin of migrating the pools when updating the XCM version.
+	///
+	/// An error of type `()` is returned if the version conversion fails for XCM locations.
+	/// This error should be mapped by the caller to a more descriptive one.
+	pub fn get_assets_in_pool_with(asset: Location) -> Result<Vec<AssetId>, ()> {
+		// convert latest to the `L` version.
+		let asset: L = asset.try_into().map_err(|_| ())?;
+		Self::iter_assets_in_pool_with(&asset)
+			.map(|location| {
+				// convert `L` to the latest `AssetId`
+				location.try_into().map_err(|_| ()).map(AssetId)
+			})
+			.collect::<Result<Vec<_>, _>>()
+	}
+
+	/// Provides a current prices. Wrapper over
+	/// `pallet_asset_conversion::Pallet::<T>::quote_price_tokens_for_exact_tokens`.
+	///
+	/// An error of type `()` is returned if the version conversion fails for XCM locations.
+	/// This error should be mapped by the caller to a more descriptive one.
+	pub fn quote_price_tokens_for_exact_tokens(
+		asset_1: Location,
+		asset_2: Location,
+		amount: Runtime::Balance,
+		include_fees: bool,
+	) -> Result<Option<Runtime::Balance>, ()> {
+		// Convert latest to the `L` version.
+		let asset_1: L = asset_1.try_into().map_err(|_| ())?;
+		let asset_2: L = asset_2.try_into().map_err(|_| ())?;
+
+		// Quote swap price.
+		Ok(pallet_asset_conversion::Pallet::<Runtime>::quote_price_tokens_for_exact_tokens(
+			asset_1,
+			asset_2,
+			amount,
+			include_fees,
+		))
+	}
+
+	/// Helper function for filtering pool.
+	pub fn iter_assets_in_pool_with(asset: &L) -> impl Iterator<Item = L> + '_ {
+		pallet_asset_conversion::Pools::<Runtime>::iter_keys().filter_map(|(asset_1, asset_2)| {
 			if asset_1 == *asset {
 				Some(asset_2)
 			} else if asset_2 == *asset {
@@ -163,8 +201,7 @@ pub fn get_assets_in_pool_with<
 				None
 			}
 		})
-		.map(|location| location.try_into().map_err(|_| ()).map(AssetId))
-		.collect::<Result<Vec<_>, _>>()
+	}
 }
 
 #[cfg(test)]