Companion for #13352 (#2180)

* Assets balances

* Update docs

* AssetsApi with MultiLocation as preparation for multi pallet_assets instances (#2187)

* AssetsApi with MultiLocation for Westmint + assets-common

* AssetsApi with MultiLocation for Statemine/t

* typo

* typo for check-docs job

* WIP: AssetsApi return MultiAsset instead of (MultiLocation, Balance)

* WIP: assets_api + conversion refactor

* WIP: assets_api + conversion refactor

* Finished asset runtimes

* Refactor AssetsApi to FungiblesApi

* Refactor

* Fix check-rust-docs

* Removed todo

* Fix check-rust-doc

* Update parachains/runtimes/assets/common/Cargo.toml

Co-authored-by: Bastian Köcher <git@kchr.de>

* update lockfile for {"substrate", "polkadot"}

---------

Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: parity-processbot <>
Co-authored-by: Bastian Köcher <git@kchr.de>

cumulus/Cargo.toml

@@ -35,6 +35,7 @@ members = [
 	"parachains/runtimes/testing/rococo-parachain",
 	"parachains/runtimes/starters/shell",
 	"parachains/runtimes/starters/seedling",
+	"parachains/runtimes/assets/common",
 	"parachains/runtimes/assets/statemint",
 	"parachains/runtimes/assets/statemine",
 	"parachains/runtimes/assets/westmint",

cumulus/parachains/runtimes/assets/common/Cargo.toml

@@ -0,0 +1,38 @@
+[package]
+name = "assets-common"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2021"
+description = "Assets common utilities"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false, features = ["derive"] }
+
+# Substrate
+frame-support = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
+sp-api = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
+sp-std = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
+
+# Polkadot
+xcm = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
+xcm-builder = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
+xcm-executor = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
+
+# Cumulus
+parachains-common = { path = "../../../common", default-features = false }
+
+[build-dependencies]
+substrate-wasm-builder = { git = "https://github.com/paritytech/substrate", branch = "master" }
+
+[features]
+default = [ "std" ]
+std = [
+	"codec/std",
+	"frame-support/std",
+	"parachains-common/std",
+	"sp-api/std",
+	"sp-std/std",
+	"xcm/std",
+	"xcm-builder/std",
+	"xcm-executor/std",
+]

cumulus/parachains/runtimes/assets/common/src/fungible_conversion.rs

@@ -0,0 +1,136 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2018-2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Runtime API definition for assets.
+
+use crate::runtime_api::FungiblesAccessError;
+use sp_std::{borrow::Borrow, vec::Vec};
+use xcm::latest::{MultiAsset, MultiLocation};
+use xcm_builder::ConvertedConcreteId;
+use xcm_executor::traits::{Convert, MatchesFungibles};
+
+/// Converting any [`(AssetId, Balance)`] to [`MultiAsset`]
+pub trait MultiAssetConverter<AssetId, Balance, ConvertAssetId, ConvertBalance>:
+	MatchesFungibles<AssetId, Balance>
+where
+	AssetId: Clone,
+	Balance: Clone,
+	ConvertAssetId: Convert<MultiLocation, AssetId>,
+	ConvertBalance: Convert<u128, Balance>,
+{
+	fn convert_ref(
+		value: impl Borrow<(AssetId, Balance)>,
+	) -> Result<MultiAsset, FungiblesAccessError>;
+}
+
+impl<
+		AssetId: Clone,
+		Balance: Clone,
+		ConvertAssetId: Convert<MultiLocation, AssetId>,
+		ConvertBalance: Convert<u128, Balance>,
+	> MultiAssetConverter<AssetId, Balance, ConvertAssetId, ConvertBalance>
+	for ConvertedConcreteId<AssetId, Balance, ConvertAssetId, ConvertBalance>
+{
+	fn convert_ref(
+		value: impl Borrow<(AssetId, Balance)>,
+	) -> Result<MultiAsset, FungiblesAccessError> {
+		let (asset_id, balance) = value.borrow();
+		match ConvertAssetId::reverse_ref(asset_id) {
+			Ok(asset_id_as_multilocation) => match ConvertBalance::reverse_ref(balance) {
+				Ok(amount) => Ok((asset_id_as_multilocation, amount).into()),
+				Err(_) => Err(FungiblesAccessError::AmountToBalanceConversionFailed),
+			},
+			Err(_) => Err(FungiblesAccessError::AssetIdConversionFailed),
+		}
+	}
+}
+
+/// Helper function to convert collections with [`(AssetId, Balance)`] to [`MultiAsset`]
+pub fn convert<'a, AssetId, Balance, ConvertAssetId, ConvertBalance, Converter>(
+	items: impl Iterator<Item = &'a (AssetId, Balance)>,
+) -> Result<Vec<MultiAsset>, FungiblesAccessError>
+where
+	AssetId: Clone + 'a,
+	Balance: Clone + 'a,
+	ConvertAssetId: Convert<MultiLocation, AssetId>,
+	ConvertBalance: Convert<u128, Balance>,
+	Converter: MultiAssetConverter<AssetId, Balance, ConvertAssetId, ConvertBalance>,
+{
+	items.map(Converter::convert_ref).collect()
+}
+
+/// Helper function to convert `Balance` with MultiLocation` to `MultiAsset`
+pub fn convert_balance<
+	T: frame_support::pallet_prelude::Get<MultiLocation>,
+	Balance: TryInto<u128>,
+>(
+	balance: Balance,
+) -> Result<MultiAsset, FungiblesAccessError> {
+	match balance.try_into() {
+		Ok(balance) => Ok((T::get(), balance).into()),
+		Err(_) => Err(FungiblesAccessError::AmountToBalanceConversionFailed),
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	use xcm::latest::prelude::*;
+	use xcm_executor::traits::{Identity, JustTry};
+
+	type Converter = ConvertedConcreteId<MultiLocation, u64, Identity, JustTry>;
+
+	#[test]
+	fn converted_concrete_id_fungible_multi_asset_conversion_roundtrip_works() {
+		let location = MultiLocation::new(0, X1(GlobalConsensus(ByGenesis([0; 32]))));
+		let amount = 123456_u64;
+		let expected_multi_asset = MultiAsset {
+			id: Concrete(MultiLocation::new(0, X1(GlobalConsensus(ByGenesis([0; 32]))))),
+			fun: Fungible(123456_u128),
+		};
+
+		assert_eq!(
+			Converter::matches_fungibles(&expected_multi_asset).map_err(|_| ()),
+			Ok((location, amount))
+		);
+
+		assert_eq!(Converter::convert_ref((location, amount)), Ok(expected_multi_asset));
+	}
+
+	#[test]
+	fn converted_concrete_id_fungible_multi_asset_conversion_collection_works() {
+		let data = vec![
+			(MultiLocation::new(0, X1(GlobalConsensus(ByGenesis([0; 32])))), 123456_u64),
+			(MultiLocation::new(1, X1(GlobalConsensus(ByGenesis([1; 32])))), 654321_u64),
+		];
+
+		let expected_data = vec![
+			MultiAsset {
+				id: Concrete(MultiLocation::new(0, X1(GlobalConsensus(ByGenesis([0; 32]))))),
+				fun: Fungible(123456_u128),
+			},
+			MultiAsset {
+				id: Concrete(MultiLocation::new(1, X1(GlobalConsensus(ByGenesis([1; 32]))))),
+				fun: Fungible(654321_u128),
+			},
+		];
+
+		assert_eq!(convert::<_, _, _, _, Converter>(data.iter()), Ok(expected_data));
+	}
+}

cumulus/parachains/runtimes/assets/common/src/lib.rs

@@ -0,0 +1,70 @@
+// Copyright (C) 2023 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+pub mod fungible_conversion;
+pub mod runtime_api;
+
+use parachains_common::AssetIdForTrustBackedAssets;
+use xcm_builder::{AsPrefixedGeneralIndex, ConvertedConcreteId};
+use xcm_executor::traits::JustTry;
+
+/// `MultiLocation` vs `AssetIdForTrustBackedAssets` converter for `TrustBackedAssets`
+pub type AssetIdForTrustBackedAssetsConvert<TrustBackedAssetsPalletLocation> =
+	AsPrefixedGeneralIndex<TrustBackedAssetsPalletLocation, AssetIdForTrustBackedAssets, JustTry>;
+
+/// [`ConvertedConcreteId`] converter dedicated for `TrustBackedAssets`
+pub type TrustBackedAssetsConvertedConcreteId<TrustBackedAssetsPalletLocation, Balance> =
+	ConvertedConcreteId<
+		AssetIdForTrustBackedAssets,
+		Balance,
+		AssetIdForTrustBackedAssetsConvert<TrustBackedAssetsPalletLocation>,
+		JustTry,
+	>;
+
+#[cfg(test)]
+mod tests {
+
+	use super::*;
+	use xcm::latest::prelude::*;
+	use xcm_executor::traits::Convert;
+
+	frame_support::parameter_types! {
+		pub TrustBackedAssetsPalletLocation: MultiLocation = MultiLocation::new(5, X1(PalletInstance(13)));
+	}
+
+	#[test]
+	fn asset_id_for_trust_backed_assets_convert_works() {
+		let local_asset_id = 123456789 as AssetIdForTrustBackedAssets;
+		let expected_reverse_ref =
+			MultiLocation::new(5, X2(PalletInstance(13), GeneralIndex(local_asset_id.into())));
+
+		assert_eq!(
+			AssetIdForTrustBackedAssetsConvert::<TrustBackedAssetsPalletLocation>::reverse_ref(
+				local_asset_id
+			)
+			.unwrap(),
+			expected_reverse_ref
+		);
+		assert_eq!(
+			AssetIdForTrustBackedAssetsConvert::<TrustBackedAssetsPalletLocation>::convert_ref(
+				expected_reverse_ref
+			)
+			.unwrap(),
+			local_asset_id
+		);
+	}
+}

cumulus/parachains/runtimes/assets/common/src/runtime_api.rs

@@ -0,0 +1,41 @@
+// Copyright (C) 2023 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Runtime API definition for fungibles.
+
+use codec::{Codec, Decode, Encode};
+use frame_support::RuntimeDebug;
+use sp_std::vec::Vec;
+use xcm::latest::MultiAsset;
+
+/// The possible errors that can happen querying the storage of assets.
+#[derive(Eq, PartialEq, Encode, Decode, RuntimeDebug)]
+pub enum FungiblesAccessError {
+	/// `MultiLocation` to `AssetId`/`ClassId` conversion failed.
+	AssetIdConversionFailed,
+	/// `u128` amount to currency `Balance` conversion failed.
+	AmountToBalanceConversionFailed,
+}
+
+sp_api::decl_runtime_apis! {
+	/// The API for querying account's balances from runtime.
+	pub trait FungiblesApi<AccountId>
+	where
+		AccountId: Codec,
+	{
+		/// Returns the list of all [`MultiAsset`] that an `AccountId` has.
+		fn query_account_balances(account: AccountId) -> Result<Vec<MultiAsset>, FungiblesAccessError>;
+	}
+}

cumulus/parachains/runtimes/assets/statemine/Cargo.toml

@@ -49,6 +49,7 @@ pallet-state-trie-migration = { git = "https://github.com/paritytech/substrate",
 # Polkadot
 kusama-runtime-constants = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 pallet-xcm = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
+pallet-xcm-benchmarks = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false, optional = true }
 polkadot-core-primitives = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 polkadot-parachain = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 polkadot-runtime-common = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
@@ -69,8 +70,7 @@ cumulus-primitives-utility = { path = "../../../../primitives/utility", default-
 pallet-collator-selection = { path = "../../../../pallets/collator-selection", default-features = false }
 parachain-info = { path = "../../../pallets/parachain-info", default-features = false }
 parachains-common = { path = "../../../common", default-features = false }
-pallet-xcm-benchmarks = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false, optional = true }
-
+assets-common = { path = "../common", default-features = false }
 
 [dev-dependencies]
 asset-test-utils = { path = "../test-utils"}
@@ -187,4 +187,5 @@ std = [
 	"pallet-collator-selection/std",
 	"parachain-info/std",
 	"parachains-common/std",
+	"assets-common/std",
 ]

cumulus/parachains/runtimes/assets/statemine/src/lib.rs

@@ -64,7 +64,7 @@ use parachains_common::{
 	Index, Signature, AVERAGE_ON_INITIALIZE_RATIO, HOURS, MAXIMUM_BLOCK_WEIGHT,
 	NORMAL_DISPATCH_RATIO, SLOT_DURATION,
 };
-use xcm_config::{KsmLocation, XcmConfig};
+use xcm_config::{KsmLocation, TrustBackedAssetsConvertedConcreteId, XcmConfig};
 
 #[cfg(any(feature = "std", test))]
 pub use sp_runtime::BuildStorage;
@@ -831,6 +831,34 @@ impl_runtime_apis! {
 		}
 	}
 
+	impl assets_common::runtime_api::FungiblesApi<
+		Block,
+		AccountId,
+	> for Runtime
+	{
+		fn query_account_balances(account: AccountId) -> Result<Vec<xcm::latest::MultiAsset>, assets_common::runtime_api::FungiblesAccessError> {
+			use assets_common::fungible_conversion::{convert, convert_balance};
+			Ok([
+				// collect pallet_balance
+				{
+					let balance = Balances::free_balance(account.clone());
+					if balance > 0 {
+						vec![convert_balance::<KsmLocation, Balance>(balance)?]
+					} else {
+						vec![]
+					}
+				},
+				// collect pallet_assets (TrustBackedAssets)
+				convert::<_, _, _, _, TrustBackedAssetsConvertedConcreteId>(
+					Assets::account_balances(account)
+						.iter()
+						.filter(|(_, balance)| balance > &0)
+				)?,
+				// collect ... e.g. pallet_assets ForeignAssets
+			].concat())
+		}
+	}
+
 	impl cumulus_primitives_core::CollectCollationInfo<Block> for Runtime {
 		fn collect_collation_info(header: &<Block as BlockT>::Header) -> cumulus_primitives_core::CollationInfo {
 			ParachainSystem::collect_collation_info(header)

cumulus/parachains/runtimes/assets/statemine/src/xcm_config.rs

@@ -14,9 +14,9 @@
 // limitations under the License.
 
 use super::{
-	AccountId, AllPalletsWithSystem, AssetIdForTrustBackedAssets, Assets, Authorship, Balance,
-	Balances, ParachainInfo, ParachainSystem, PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent,
-	RuntimeOrigin, TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
+	AccountId, AllPalletsWithSystem, Assets, Authorship, Balance, Balances, ParachainInfo,
+	ParachainSystem, PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent, RuntimeOrigin,
+	TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
 };
 use frame_support::{
 	match_types, parameter_types,
@@ -34,17 +34,13 @@ use sp_runtime::traits::ConvertInto;
 use xcm::latest::prelude::*;
 use xcm_builder::{
 	AccountId32Aliases, AllowExplicitUnpaidExecutionFrom, AllowKnownQueryResponses,
-	AllowSubscriptionsFrom, AllowTopLevelPaidExecutionFrom, AsPrefixedGeneralIndex,
-	ConvertedConcreteId, CurrencyAdapter, EnsureXcmOrigin, FungiblesAdapter, IsConcrete, LocalMint,
-	NativeAsset, ParentAsSuperuser, ParentIsPreset, RelayChainAsNative, SiblingParachainAsNative,
-	SiblingParachainConvertsVia, SignedAccountId32AsNative, SignedToAccountId32,
-	SovereignSignedViaLocation, TakeWeightCredit, UsingComponents, WeightInfoBounds,
-	WithComputedOrigin,
-};
-use xcm_executor::{
-	traits::{JustTry, WithOriginFilter},
-	XcmExecutor,
+	AllowSubscriptionsFrom, AllowTopLevelPaidExecutionFrom, CurrencyAdapter, EnsureXcmOrigin,
+	FungiblesAdapter, IsConcrete, LocalMint, NativeAsset, ParentAsSuperuser, ParentIsPreset,
+	RelayChainAsNative, SiblingParachainAsNative, SiblingParachainConvertsVia,
+	SignedAccountId32AsNative, SignedToAccountId32, SovereignSignedViaLocation, TakeWeightCredit,
+	UsingComponents, WeightInfoBounds, WithComputedOrigin,
 };
+use xcm_executor::{traits::WithOriginFilter, XcmExecutor};
 
 parameter_types! {
 	pub const KsmLocation: MultiLocation = MultiLocation::parent();
@@ -84,21 +80,16 @@ pub type CurrencyTransactor = CurrencyAdapter<
 	(),
 >;
 
+/// `AssetId/Balancer` converter for `TrustBackedAssets`
+pub type TrustBackedAssetsConvertedConcreteId =
+	assets_common::TrustBackedAssetsConvertedConcreteId<TrustBackedAssetsPalletLocation, Balance>;
+
 /// Means for transacting assets besides the native currency on this chain.
 pub type FungiblesTransactor = FungiblesAdapter<
 	// Use this fungibles implementation:
 	Assets,
 	// Use this currency when it is a fungible asset matching the given location or name:
-	ConvertedConcreteId<
-		AssetIdForTrustBackedAssets,
-		Balance,
-		AsPrefixedGeneralIndex<
-			TrustBackedAssetsPalletLocation,
-			AssetIdForTrustBackedAssets,
-			JustTry,
-		>,
-		JustTry,
-	>,
+	TrustBackedAssetsConvertedConcreteId,
 	// Convert an XCM MultiLocation into a local account id:
 	LocationToAccountId,
 	// Our chain's account ID type (we can't get away without mentioning it explicitly):
@@ -302,16 +293,7 @@ impl xcm_executor::Config for XcmConfig {
 		cumulus_primitives_utility::TakeFirstAssetTrader<
 			AccountId,
 			AssetFeeAsExistentialDepositMultiplierFeeCharger,
-			ConvertedConcreteId<
-				AssetIdForTrustBackedAssets,
-				Balance,
-				AsPrefixedGeneralIndex<
-					TrustBackedAssetsPalletLocation,
-					AssetIdForTrustBackedAssets,
-					JustTry,
-				>,
-				JustTry,
-			>,
+			TrustBackedAssetsConvertedConcreteId,
 			Assets,
 			cumulus_primitives_utility::XcmFeesTo32ByteAccount<
 				FungiblesTransactor,

cumulus/parachains/runtimes/assets/statemine/tests/tests.rs

@@ -3,20 +3,27 @@ use codec::Encode;
 use cumulus_primitives_utility::ChargeWeightInFungibles;
 use frame_support::{
 	assert_noop, assert_ok, sp_io,
-	traits::PalletInfo,
 	weights::{Weight, WeightToFee as WeightToFeeT},
 };
-use parachains_common::{AccountId, AuraId};
-use statemine_runtime::xcm_config::AssetFeeAsExistentialDepositMultiplierFeeCharger;
+use parachains_common::{AccountId, AuraId, Balance};
+use statemine_runtime::xcm_config::{
+	AssetFeeAsExistentialDepositMultiplierFeeCharger, KsmLocation, TrustBackedAssetsPalletLocation,
+};
 pub use statemine_runtime::{
 	constants::fee::WeightToFee, xcm_config::XcmConfig, Assets, Balances, ExistentialDeposit,
 	ReservedDmpWeight, Runtime, SessionKeys, System,
 };
 use xcm::latest::prelude::*;
-use xcm_executor::{traits::WeightTrader, XcmExecutor};
+use xcm_executor::{
+	traits::{Convert, WeightTrader},
+	XcmExecutor,
+};
 
 pub const ALICE: [u8; 32] = [1u8; 32];
 
+type AssetIdForTrustBackedAssetsConvert =
+	assets_common::AssetIdForTrustBackedAssetsConvert<TrustBackedAssetsPalletLocation>;
+
 #[test]
 fn test_asset_xcm_trader() {
 	ExtBuilder::<Runtime>::default()
@@ -48,16 +55,8 @@ fn test_asset_xcm_trader() {
 			));
 
 			// get asset id as multilocation
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(local_asset_id.into()),
-				),
-			);
+			let asset_multilocation =
+				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap();
 
 			// Set Alice as block author, who will receive fees
 			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));
@@ -95,12 +94,15 @@ fn test_asset_xcm_trader() {
 
 			// Make sure author(Alice) has received the amount
 			assert_eq!(
-				Assets::balance(1, AccountId::from(ALICE)),
+				Assets::balance(local_asset_id, AccountId::from(ALICE)),
 				minimum_asset_balance + asset_amount_needed
 			);
 
 			// We also need to ensure the total supply increased
-			assert_eq!(Assets::total_supply(1), minimum_asset_balance + asset_amount_needed);
+			assert_eq!(
+				Assets::total_supply(local_asset_id),
+				minimum_asset_balance + asset_amount_needed
+			);
 		});
 }
 
@@ -141,16 +143,7 @@ fn test_asset_xcm_trader_with_refund() {
 			// We are going to buy 4e9 weight
 			let bought = Weight::from_ref_time(4_000_000_000u64);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			// lets calculate amount needed
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
@@ -219,16 +212,7 @@ fn test_asset_xcm_trader_refund_not_possible_since_amount_less_than_ed() {
 			// We are going to buy small amount
 			let bought = Weight::from_ref_time(500_000_000u64);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
 
@@ -279,16 +263,7 @@ fn test_that_buying_ed_refund_does_not_refund() {
 			// We are gonna buy ED
 			let bought = Weight::from_ref_time(ExistentialDeposit::get().try_into().unwrap());
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
 
@@ -363,16 +338,7 @@ fn test_asset_xcm_trader_not_possible_for_non_sufficient_assets() {
 			// lets calculate amount needed
 			let asset_amount_needed = WeightToFee::weight_to_fee(&bought);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let asset: MultiAsset = (asset_multilocation, asset_amount_needed).into();
 
@@ -390,6 +356,75 @@ fn test_asset_xcm_trader_not_possible_for_non_sufficient_assets() {
 		});
 }
 
+#[test]
+fn test_assets_balances_api_works() {
+	use assets_common::runtime_api::runtime_decl_for_FungiblesApi::FungiblesApi;
+
+	ExtBuilder::<Runtime>::default()
+		.with_collators(vec![AccountId::from(ALICE)])
+		.with_session_keys(vec![(
+			AccountId::from(ALICE),
+			AccountId::from(ALICE),
+			SessionKeys { aura: AuraId::from(sp_core::sr25519::Public::from_raw(ALICE)) },
+		)])
+		.build()
+		.execute_with(|| {
+			let local_asset_id = 1;
+
+			// check before
+			assert_eq!(Assets::balance(local_asset_id, AccountId::from(ALICE)), 0);
+			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), 0);
+			assert!(Runtime::query_account_balances(AccountId::from(ALICE)).unwrap().is_empty());
+
+			// Drip some balance
+			use frame_support::traits::fungible::Mutate;
+			let some_currency = ExistentialDeposit::get();
+			Balances::mint_into(&AccountId::from(ALICE), some_currency).unwrap();
+
+			// We need root origin to create a sufficient asset
+			let minimum_asset_balance = 3333333_u128;
+			assert_ok!(Assets::force_create(
+				RuntimeHelper::<Runtime>::root_origin(),
+				local_asset_id.into(),
+				AccountId::from(ALICE).into(),
+				true,
+				minimum_asset_balance
+			));
+
+			// We first mint enough asset for the account to exist for assets
+			assert_ok!(Assets::mint(
+				RuntimeHelper::<Runtime>::origin_of(AccountId::from(ALICE)),
+				local_asset_id.into(),
+				AccountId::from(ALICE).into(),
+				minimum_asset_balance
+			));
+
+			// check after
+			assert_eq!(
+				Assets::balance(local_asset_id, AccountId::from(ALICE)),
+				minimum_asset_balance
+			);
+			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), some_currency);
+
+			let result = Runtime::query_account_balances(AccountId::from(ALICE)).unwrap();
+			assert_eq!(result.len(), 2);
+
+			// check currency
+			assert!(result.iter().any(|asset| asset.eq(
+				&assets_common::fungible_conversion::convert_balance::<KsmLocation, Balance>(
+					some_currency
+				)
+				.unwrap()
+			)));
+			// check trusted asset
+			assert!(result.iter().any(|asset| asset.eq(&(
+				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap(),
+				minimum_asset_balance
+			)
+				.into())));
+		});
+}
+
 #[test]
 fn receive_teleported_asset_works() {
 	ExtBuilder::<Runtime>::default()

cumulus/parachains/runtimes/assets/statemint/Cargo.toml

@@ -47,6 +47,7 @@ sp-version = { git = "https://github.com/paritytech/substrate", default-features
 
 # Polkadot
 pallet-xcm = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
+pallet-xcm-benchmarks = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false, optional = true }
 polkadot-core-primitives = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 polkadot-parachain = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 polkadot-runtime-common = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
@@ -68,7 +69,7 @@ cumulus-primitives-utility = { path = "../../../../primitives/utility", default-
 pallet-collator-selection = { path = "../../../../pallets/collator-selection", default-features = false }
 parachain-info = { path = "../../../pallets/parachain-info", default-features = false }
 parachains-common = { path = "../../../common", default-features = false }
-pallet-xcm-benchmarks = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false, optional = true }
+assets-common = { path = "../common", default-features = false }
 
 [dev-dependencies]
 hex-literal = "0.3.4"
@@ -176,4 +177,5 @@ std = [
 	"pallet-collator-selection/std",
 	"parachain-info/std",
 	"parachains-common/std",
+	"assets-common/std",
 ]

cumulus/parachains/runtimes/assets/statemint/src/lib.rs

@@ -93,7 +93,9 @@ use parachains_common::{
 	Signature, StatemintAuraId as AuraId, AVERAGE_ON_INITIALIZE_RATIO, HOURS, MAXIMUM_BLOCK_WEIGHT,
 	NORMAL_DISPATCH_RATIO, SLOT_DURATION,
 };
-use xcm_config::{DotLocation, XcmConfig, XcmOriginToTransactDispatchOrigin};
+use xcm_config::{
+	DotLocation, TrustBackedAssetsConvertedConcreteId, XcmConfig, XcmOriginToTransactDispatchOrigin,
+};
 
 #[cfg(any(feature = "std", test))]
 pub use sp_runtime::BuildStorage;
@@ -828,6 +830,34 @@ impl_runtime_apis! {
 		}
 	}
 
+	impl assets_common::runtime_api::FungiblesApi<
+		Block,
+		AccountId,
+	> for Runtime
+	{
+		fn query_account_balances(account: AccountId) -> Result<Vec<xcm::latest::MultiAsset>, assets_common::runtime_api::FungiblesAccessError> {
+			use assets_common::fungible_conversion::{convert, convert_balance};
+			Ok([
+				// collect pallet_balance
+				{
+					let balance = Balances::free_balance(account.clone());
+					if balance > 0 {
+						vec![convert_balance::<DotLocation, Balance>(balance)?]
+					} else {
+						vec![]
+					}
+				},
+				// collect pallet_assets (TrustBackedAssets)
+				convert::<_, _, _, _, TrustBackedAssetsConvertedConcreteId>(
+					Assets::account_balances(account)
+						.iter()
+						.filter(|(_, balance)| balance > &0)
+				)?,
+				// collect ... e.g. pallet_assets ForeignAssets
+			].concat())
+		}
+	}
+
 	impl cumulus_primitives_core::CollectCollationInfo<Block> for Runtime {
 		fn collect_collation_info(header: &<Block as BlockT>::Header) -> cumulus_primitives_core::CollationInfo {
 			ParachainSystem::collect_collation_info(header)

cumulus/parachains/runtimes/assets/statemint/src/xcm_config.rs

@@ -14,9 +14,9 @@
 // limitations under the License.
 
 use super::{
-	AccountId, AllPalletsWithSystem, AssetIdForTrustBackedAssets, Assets, Authorship, Balance,
-	Balances, ParachainInfo, ParachainSystem, PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent,
-	RuntimeOrigin, TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
+	AccountId, AllPalletsWithSystem, Assets, Authorship, Balance, Balances, ParachainInfo,
+	ParachainSystem, PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent, RuntimeOrigin,
+	TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
 };
 use frame_support::{
 	match_types, parameter_types,
@@ -34,17 +34,13 @@ use sp_runtime::traits::ConvertInto;
 use xcm::latest::prelude::*;
 use xcm_builder::{
 	AccountId32Aliases, AllowExplicitUnpaidExecutionFrom, AllowKnownQueryResponses,
-	AllowSubscriptionsFrom, AllowTopLevelPaidExecutionFrom, AsPrefixedGeneralIndex,
-	ConvertedConcreteId, CurrencyAdapter, EnsureXcmOrigin, FungiblesAdapter, IsConcrete, LocalMint,
-	NativeAsset, ParentAsSuperuser, ParentIsPreset, RelayChainAsNative, SiblingParachainAsNative,
-	SiblingParachainConvertsVia, SignedAccountId32AsNative, SignedToAccountId32,
-	SovereignSignedViaLocation, TakeWeightCredit, UsingComponents, WeightInfoBounds,
-	WithComputedOrigin,
-};
-use xcm_executor::{
-	traits::{JustTry, WithOriginFilter},
-	XcmExecutor,
+	AllowSubscriptionsFrom, AllowTopLevelPaidExecutionFrom, CurrencyAdapter, EnsureXcmOrigin,
+	FungiblesAdapter, IsConcrete, LocalMint, NativeAsset, ParentAsSuperuser, ParentIsPreset,
+	RelayChainAsNative, SiblingParachainAsNative, SiblingParachainConvertsVia,
+	SignedAccountId32AsNative, SignedToAccountId32, SovereignSignedViaLocation, TakeWeightCredit,
+	UsingComponents, WeightInfoBounds, WithComputedOrigin,
 };
+use xcm_executor::{traits::WithOriginFilter, XcmExecutor};
 
 parameter_types! {
 	pub const DotLocation: MultiLocation = MultiLocation::parent();
@@ -84,21 +80,16 @@ pub type CurrencyTransactor = CurrencyAdapter<
 	(),
 >;
 
+/// `AssetId/Balancer` converter for `TrustBackedAssets``
+pub type TrustBackedAssetsConvertedConcreteId =
+	assets_common::TrustBackedAssetsConvertedConcreteId<TrustBackedAssetsPalletLocation, Balance>;
+
 /// Means for transacting assets besides the native currency on this chain.
 pub type FungiblesTransactor = FungiblesAdapter<
 	// Use this fungibles implementation:
 	Assets,
 	// Use this currency when it is a fungible asset matching the given location or name:
-	ConvertedConcreteId<
-		AssetIdForTrustBackedAssets,
-		Balance,
-		AsPrefixedGeneralIndex<
-			TrustBackedAssetsPalletLocation,
-			AssetIdForTrustBackedAssets,
-			JustTry,
-		>,
-		JustTry,
-	>,
+	TrustBackedAssetsConvertedConcreteId,
 	// Convert an XCM MultiLocation into a local account id:
 	LocationToAccountId,
 	// Our chain's account ID type (we can't get away without mentioning it explicitly):
@@ -302,16 +293,7 @@ impl xcm_executor::Config for XcmConfig {
 		cumulus_primitives_utility::TakeFirstAssetTrader<
 			AccountId,
 			AssetFeeAsExistentialDepositMultiplierFeeCharger,
-			ConvertedConcreteId<
-				AssetIdForTrustBackedAssets,
-				Balance,
-				AsPrefixedGeneralIndex<
-					TrustBackedAssetsPalletLocation,
-					AssetIdForTrustBackedAssets,
-					JustTry,
-				>,
-				JustTry,
-			>,
+			TrustBackedAssetsConvertedConcreteId,
 			Assets,
 			cumulus_primitives_utility::XcmFeesTo32ByteAccount<
 				FungiblesTransactor,

cumulus/parachains/runtimes/assets/statemint/tests/tests.rs

@@ -3,20 +3,27 @@ use codec::Encode;
 use cumulus_primitives_utility::ChargeWeightInFungibles;
 use frame_support::{
 	assert_noop, assert_ok, sp_io,
-	traits::PalletInfo,
 	weights::{Weight, WeightToFee as WeightToFeeT},
 };
-use parachains_common::{AccountId, StatemintAuraId as AuraId};
-use statemint_runtime::xcm_config::AssetFeeAsExistentialDepositMultiplierFeeCharger;
+use parachains_common::{AccountId, Balance, StatemintAuraId as AuraId};
+use statemint_runtime::xcm_config::{
+	AssetFeeAsExistentialDepositMultiplierFeeCharger, DotLocation, TrustBackedAssetsPalletLocation,
+};
 pub use statemint_runtime::{
 	constants::fee::WeightToFee, xcm_config::XcmConfig, Assets, Balances, ExistentialDeposit,
 	ReservedDmpWeight, Runtime, SessionKeys, System,
 };
 use xcm::latest::prelude::*;
-use xcm_executor::{traits::WeightTrader, XcmExecutor};
+use xcm_executor::{
+	traits::{Convert, WeightTrader},
+	XcmExecutor,
+};
 
 pub const ALICE: [u8; 32] = [1u8; 32];
 
+type AssetIdForTrustBackedAssetsConvert =
+	assets_common::AssetIdForTrustBackedAssetsConvert<TrustBackedAssetsPalletLocation>;
+
 #[test]
 fn test_asset_xcm_trader() {
 	ExtBuilder::<Runtime>::default()
@@ -48,16 +55,8 @@ fn test_asset_xcm_trader() {
 			));
 
 			// get asset id as multilocation
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(local_asset_id.into()),
-				),
-			);
+			let asset_multilocation =
+				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap();
 
 			// Set Alice as block author, who will receive fees
 			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));
@@ -98,12 +97,15 @@ fn test_asset_xcm_trader() {
 
 			// Make sure author(Alice) has received the amount
 			assert_eq!(
-				Assets::balance(1, AccountId::from(ALICE)),
+				Assets::balance(local_asset_id, AccountId::from(ALICE)),
 				minimum_asset_balance + asset_amount_needed
 			);
 
 			// We also need to ensure the total supply increased
-			assert_eq!(Assets::total_supply(1), minimum_asset_balance + asset_amount_needed);
+			assert_eq!(
+				Assets::total_supply(local_asset_id),
+				minimum_asset_balance + asset_amount_needed
+			);
 		});
 }
 
@@ -147,16 +149,7 @@ fn test_asset_xcm_trader_with_refund() {
 			// bit more of weight
 			let bought = Weight::from_ref_time(400_000_000_000u64);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			// lets calculate amount needed
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
@@ -228,16 +221,7 @@ fn test_asset_xcm_trader_refund_not_possible_since_amount_less_than_ed() {
 			// bit more of weight
 			let bought = Weight::from_ref_time(50_000_000_000u64);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
 
@@ -288,16 +272,7 @@ fn test_that_buying_ed_refund_does_not_refund() {
 			// We are gonna buy ED
 			let bought = Weight::from_ref_time(ExistentialDeposit::get().try_into().unwrap());
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
 
@@ -375,16 +350,7 @@ fn test_asset_xcm_trader_not_possible_for_non_sufficient_assets() {
 			// lets calculate amount needed
 			let asset_amount_needed = WeightToFee::weight_to_fee(&bought);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let asset: MultiAsset = (asset_multilocation, asset_amount_needed).into();
 
@@ -402,6 +368,75 @@ fn test_asset_xcm_trader_not_possible_for_non_sufficient_assets() {
 		});
 }
 
+#[test]
+fn test_assets_balances_api_works() {
+	use assets_common::runtime_api::runtime_decl_for_FungiblesApi::FungiblesApi;
+
+	ExtBuilder::<Runtime>::default()
+		.with_collators(vec![AccountId::from(ALICE)])
+		.with_session_keys(vec![(
+			AccountId::from(ALICE),
+			AccountId::from(ALICE),
+			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
+		)])
+		.build()
+		.execute_with(|| {
+			let local_asset_id = 1;
+
+			// check before
+			assert_eq!(Assets::balance(local_asset_id, AccountId::from(ALICE)), 0);
+			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), 0);
+			assert!(Runtime::query_account_balances(AccountId::from(ALICE)).unwrap().is_empty());
+
+			// Drip some balance
+			use frame_support::traits::fungible::Mutate;
+			let some_currency = ExistentialDeposit::get();
+			Balances::mint_into(&AccountId::from(ALICE), some_currency).unwrap();
+
+			// We need root origin to create a sufficient asset
+			let minimum_asset_balance = 3333333_u128;
+			assert_ok!(Assets::force_create(
+				RuntimeHelper::<Runtime>::root_origin(),
+				local_asset_id.into(),
+				AccountId::from(ALICE).into(),
+				true,
+				minimum_asset_balance
+			));
+
+			// We first mint enough asset for the account to exist for assets
+			assert_ok!(Assets::mint(
+				RuntimeHelper::<Runtime>::origin_of(AccountId::from(ALICE)),
+				local_asset_id.into(),
+				AccountId::from(ALICE).into(),
+				minimum_asset_balance
+			));
+
+			// check after
+			assert_eq!(
+				Assets::balance(local_asset_id, AccountId::from(ALICE)),
+				minimum_asset_balance
+			);
+			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), some_currency);
+
+			let result = Runtime::query_account_balances(AccountId::from(ALICE)).unwrap();
+			assert_eq!(result.len(), 2);
+
+			// check currency
+			assert!(result.iter().any(|asset| asset.eq(
+				&assets_common::fungible_conversion::convert_balance::<DotLocation, Balance>(
+					some_currency
+				)
+				.unwrap()
+			)));
+			// check trusted asset
+			assert!(result.iter().any(|asset| asset.eq(&(
+				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap(),
+				minimum_asset_balance
+			)
+				.into())));
+		});
+}
+
 #[test]
 fn receive_teleported_asset_works() {
 	ExtBuilder::<Runtime>::default()

cumulus/parachains/runtimes/assets/westmint/Cargo.toml

@@ -49,6 +49,7 @@ sp-version = { git = "https://github.com/paritytech/substrate", default-features
 
 # Polkadot
 pallet-xcm = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
+pallet-xcm-benchmarks = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false, optional = true }
 polkadot-core-primitives = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 polkadot-parachain = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 polkadot-runtime-common = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
@@ -70,7 +71,7 @@ cumulus-primitives-utility = { path = "../../../../primitives/utility", default-
 pallet-collator-selection = { path = "../../../../pallets/collator-selection", default-features = false }
 parachain-info = { path = "../../../pallets/parachain-info", default-features = false }
 parachains-common = { path = "../../../common", default-features = false }
-pallet-xcm-benchmarks = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false, optional = true }
+assets-common = { path = "../common", default-features = false }
 
 [dev-dependencies]
 hex-literal = "0.3.4"
@@ -182,4 +183,5 @@ std = [
 	"pallet-collator-selection/std",
 	"parachain-info/std",
 	"parachains-common/std",
+	"assets-common/std",
 ]

cumulus/parachains/runtimes/assets/westmint/src/lib.rs

@@ -68,7 +68,10 @@ use parachains_common::{
 	Index, Signature, AVERAGE_ON_INITIALIZE_RATIO, DAYS, HOURS, MAXIMUM_BLOCK_WEIGHT,
 	NORMAL_DISPATCH_RATIO, SLOT_DURATION,
 };
-use xcm_config::{XcmConfig, XcmOriginToTransactDispatchOrigin};
+use xcm_config::{
+	TrustBackedAssetsConvertedConcreteId, WestendLocation, XcmConfig,
+	XcmOriginToTransactDispatchOrigin,
+};
 
 #[cfg(any(feature = "std", test))]
 pub use sp_runtime::BuildStorage;
@@ -890,6 +893,34 @@ impl_runtime_apis! {
 		}
 	}
 
+	impl assets_common::runtime_api::FungiblesApi<
+		Block,
+		AccountId,
+	> for Runtime
+	{
+		fn query_account_balances(account: AccountId) -> Result<Vec<xcm::latest::MultiAsset>, assets_common::runtime_api::FungiblesAccessError> {
+			use assets_common::fungible_conversion::{convert, convert_balance};
+			Ok([
+				// collect pallet_balance
+				{
+					let balance = Balances::free_balance(account.clone());
+					if balance > 0 {
+						vec![convert_balance::<WestendLocation, Balance>(balance)?]
+					} else {
+						vec![]
+					}
+				},
+				// collect pallet_assets (TrustBackedAssets)
+				convert::<_, _, _, _, TrustBackedAssetsConvertedConcreteId>(
+					Assets::account_balances(account)
+						.iter()
+						.filter(|(_, balance)| balance > &0)
+				)?,
+				// collect ... e.g. pallet_assets ForeignAssets
+			].concat())
+		}
+	}
+
 	impl cumulus_primitives_core::CollectCollationInfo<Block> for Runtime {
 		fn collect_collation_info(header: &<Block as BlockT>::Header) -> cumulus_primitives_core::CollationInfo {
 			ParachainSystem::collect_collation_info(header)

cumulus/parachains/runtimes/assets/westmint/src/xcm_config.rs

@@ -14,9 +14,9 @@
 // limitations under the License.
 
 use super::{
-	AccountId, AllPalletsWithSystem, AssetIdForTrustBackedAssets, Assets, Authorship, Balance,
-	Balances, ParachainInfo, ParachainSystem, PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent,
-	RuntimeOrigin, TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
+	AccountId, AllPalletsWithSystem, Assets, Authorship, Balance, Balances, ParachainInfo,
+	ParachainSystem, PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent, RuntimeOrigin,
+	TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
 };
 use frame_support::{
 	match_types, parameter_types,
@@ -34,17 +34,13 @@ use sp_runtime::traits::ConvertInto;
 use xcm::latest::prelude::*;
 use xcm_builder::{
 	AccountId32Aliases, AllowExplicitUnpaidExecutionFrom, AllowKnownQueryResponses,
-	AllowSubscriptionsFrom, AllowTopLevelPaidExecutionFrom, AsPrefixedGeneralIndex,
-	ConvertedConcreteId, CurrencyAdapter, EnsureXcmOrigin, FungiblesAdapter, IsConcrete, LocalMint,
-	NativeAsset, ParentAsSuperuser, ParentIsPreset, RelayChainAsNative, SiblingParachainAsNative,
-	SiblingParachainConvertsVia, SignedAccountId32AsNative, SignedToAccountId32,
-	SovereignSignedViaLocation, TakeWeightCredit, UsingComponents, WeightInfoBounds,
-	WithComputedOrigin,
-};
-use xcm_executor::{
-	traits::{JustTry, WithOriginFilter},
-	XcmExecutor,
+	AllowSubscriptionsFrom, AllowTopLevelPaidExecutionFrom, CurrencyAdapter, EnsureXcmOrigin,
+	FungiblesAdapter, IsConcrete, LocalMint, NativeAsset, ParentAsSuperuser, ParentIsPreset,
+	RelayChainAsNative, SiblingParachainAsNative, SiblingParachainConvertsVia,
+	SignedAccountId32AsNative, SignedToAccountId32, SovereignSignedViaLocation, TakeWeightCredit,
+	UsingComponents, WeightInfoBounds, WithComputedOrigin,
 };
+use xcm_executor::{traits::WithOriginFilter, XcmExecutor};
 
 parameter_types! {
 	pub const WestendLocation: MultiLocation = MultiLocation::parent();
@@ -84,21 +80,16 @@ pub type CurrencyTransactor = CurrencyAdapter<
 	(),
 >;
 
+/// `AssetId/Balancer` converter for `TrustBackedAssets`
+pub type TrustBackedAssetsConvertedConcreteId =
+	assets_common::TrustBackedAssetsConvertedConcreteId<TrustBackedAssetsPalletLocation, Balance>;
+
 /// Means for transacting assets besides the native currency on this chain.
 pub type FungiblesTransactor = FungiblesAdapter<
 	// Use this fungibles implementation:
 	Assets,
 	// Use this currency when it is a fungible asset matching the given location or name:
-	ConvertedConcreteId<
-		AssetIdForTrustBackedAssets,
-		Balance,
-		AsPrefixedGeneralIndex<
-			TrustBackedAssetsPalletLocation,
-			AssetIdForTrustBackedAssets,
-			JustTry,
-		>,
-		JustTry,
-	>,
+	TrustBackedAssetsConvertedConcreteId,
 	// Convert an XCM MultiLocation into a local account id:
 	LocationToAccountId,
 	// Our chain's account ID type (we can't get away without mentioning it explicitly):
@@ -297,16 +288,7 @@ impl xcm_executor::Config for XcmConfig {
 		cumulus_primitives_utility::TakeFirstAssetTrader<
 			AccountId,
 			AssetFeeAsExistentialDepositMultiplierFeeCharger,
-			ConvertedConcreteId<
-				AssetIdForTrustBackedAssets,
-				Balance,
-				AsPrefixedGeneralIndex<
-					TrustBackedAssetsPalletLocation,
-					AssetIdForTrustBackedAssets,
-					JustTry,
-				>,
-				JustTry,
-			>,
+			TrustBackedAssetsConvertedConcreteId,
 			Assets,
 			cumulus_primitives_utility::XcmFeesTo32ByteAccount<
 				FungiblesTransactor,

cumulus/parachains/runtimes/assets/westmint/tests/tests.rs

@@ -3,20 +3,29 @@ use codec::{DecodeLimit, Encode};
 use cumulus_primitives_utility::ChargeWeightInFungibles;
 use frame_support::{
 	assert_noop, assert_ok, sp_io,
-	traits::PalletInfo,
 	weights::{Weight, WeightToFee as WeightToFeeT},
 };
-use parachains_common::{AccountId, AuraId};
+use parachains_common::{AccountId, AuraId, Balance};
 pub use westmint_runtime::{
-	constants::fee::WeightToFee, xcm_config::XcmConfig, Assets, Balances, ExistentialDeposit,
-	ReservedDmpWeight, Runtime, SessionKeys, System,
+	constants::fee::WeightToFee,
+	xcm_config::{TrustBackedAssetsPalletLocation, XcmConfig},
+	Assets, Balances, ExistentialDeposit, ReservedDmpWeight, Runtime, SessionKeys, System,
+};
+use westmint_runtime::{
+	xcm_config::{AssetFeeAsExistentialDepositMultiplierFeeCharger, WestendLocation},
+	RuntimeCall,
 };
-use westmint_runtime::{xcm_config::AssetFeeAsExistentialDepositMultiplierFeeCharger, RuntimeCall};
 use xcm::{latest::prelude::*, VersionedXcm, MAX_XCM_DECODE_DEPTH};
-use xcm_executor::{traits::WeightTrader, XcmExecutor};
+use xcm_executor::{
+	traits::{Convert, WeightTrader},
+	XcmExecutor,
+};
 
 pub const ALICE: [u8; 32] = [1u8; 32];
 
+type AssetIdForTrustBackedAssetsConvert =
+	assets_common::AssetIdForTrustBackedAssetsConvert<TrustBackedAssetsPalletLocation>;
+
 #[test]
 fn test_asset_xcm_trader() {
 	ExtBuilder::<Runtime>::default()
@@ -48,16 +57,8 @@ fn test_asset_xcm_trader() {
 			));
 
 			// get asset id as multilocation
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(local_asset_id.into()),
-				),
-			);
+			let asset_multilocation =
+				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap();
 
 			// Set Alice as block author, who will receive fees
 			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));
@@ -95,12 +96,15 @@ fn test_asset_xcm_trader() {
 
 			// Make sure author(Alice) has received the amount
 			assert_eq!(
-				Assets::balance(1, AccountId::from(ALICE)),
+				Assets::balance(local_asset_id, AccountId::from(ALICE)),
 				minimum_asset_balance + asset_amount_needed
 			);
 
 			// We also need to ensure the total supply increased
-			assert_eq!(Assets::total_supply(1), minimum_asset_balance + asset_amount_needed);
+			assert_eq!(
+				Assets::total_supply(local_asset_id),
+				minimum_asset_balance + asset_amount_needed
+			);
 		});
 }
 
@@ -140,16 +144,7 @@ fn test_asset_xcm_trader_with_refund() {
 
 			// We are going to buy 4e9 weight
 			let bought = Weight::from_ref_time(4_000_000_000u64);
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			// lets calculate amount needed
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
@@ -218,16 +213,7 @@ fn test_asset_xcm_trader_refund_not_possible_since_amount_less_than_ed() {
 			// We are going to buy 5e9 weight
 			let bought = Weight::from_ref_time(500_000_000u64);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
 
@@ -277,16 +263,7 @@ fn test_that_buying_ed_refund_does_not_refund() {
 
 			let bought = Weight::from_ref_time(500_000_000u64);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let amount_bought = WeightToFee::weight_to_fee(&bought);
 
@@ -361,16 +338,7 @@ fn test_asset_xcm_trader_not_possible_for_non_sufficient_assets() {
 			// lets calculate amount needed
 			let asset_amount_needed = WeightToFee::weight_to_fee(&bought);
 
-			let asset_multilocation = MultiLocation::new(
-				0,
-				X2(
-					PalletInstance(
-						<Runtime as frame_system::Config>::PalletInfo::index::<Assets>().unwrap()
-							as u8,
-					),
-					GeneralIndex(1),
-				),
-			);
+			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();
 
 			let asset: MultiAsset = (asset_multilocation, asset_amount_needed).into();
 
@@ -388,6 +356,75 @@ fn test_asset_xcm_trader_not_possible_for_non_sufficient_assets() {
 		});
 }
 
+#[test]
+fn test_assets_balances_api_works() {
+	use assets_common::runtime_api::runtime_decl_for_FungiblesApi::FungiblesApi;
+
+	ExtBuilder::<Runtime>::default()
+		.with_collators(vec![AccountId::from(ALICE)])
+		.with_session_keys(vec![(
+			AccountId::from(ALICE),
+			AccountId::from(ALICE),
+			SessionKeys { aura: AuraId::from(sp_core::sr25519::Public::from_raw(ALICE)) },
+		)])
+		.build()
+		.execute_with(|| {
+			let local_asset_id = 1;
+
+			// check before
+			assert_eq!(Assets::balance(local_asset_id, AccountId::from(ALICE)), 0);
+			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), 0);
+			assert!(Runtime::query_account_balances(AccountId::from(ALICE)).unwrap().is_empty());
+
+			// Drip some balance
+			use frame_support::traits::fungible::Mutate;
+			let some_currency = ExistentialDeposit::get();
+			Balances::mint_into(&AccountId::from(ALICE), some_currency).unwrap();
+
+			// We need root origin to create a sufficient asset
+			let minimum_asset_balance = 3333333_u128;
+			assert_ok!(Assets::force_create(
+				RuntimeHelper::<Runtime>::root_origin(),
+				local_asset_id.into(),
+				AccountId::from(ALICE).into(),
+				true,
+				minimum_asset_balance
+			));
+
+			// We first mint enough asset for the account to exist for assets
+			assert_ok!(Assets::mint(
+				RuntimeHelper::<Runtime>::origin_of(AccountId::from(ALICE)),
+				local_asset_id.into(),
+				AccountId::from(ALICE).into(),
+				minimum_asset_balance
+			));
+
+			// check after
+			assert_eq!(
+				Assets::balance(local_asset_id, AccountId::from(ALICE)),
+				minimum_asset_balance
+			);
+			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), some_currency);
+
+			let result = Runtime::query_account_balances(AccountId::from(ALICE)).unwrap();
+			assert_eq!(result.len(), 2);
+
+			// check currency
+			assert!(result.iter().any(|asset| asset.eq(
+				&assets_common::fungible_conversion::convert_balance::<WestendLocation, Balance>(
+					some_currency
+				)
+				.unwrap()
+			)));
+			// check trusted asset
+			assert!(result.iter().any(|asset| asset.eq(&(
+				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap(),
+				minimum_asset_balance
+			)
+				.into())));
+		});
+}
+
 #[test]
 fn receive_teleported_asset_works() {
 	ExtBuilder::<Runtime>::default()