[XCM]XcmPaymentApi::query_delivery_fees() allow querying fee using custom asset

polkadot/xcm/xcm-runtime-apis/src/fees.rs

@@ -34,6 +34,7 @@ sp_api::decl_runtime_apis! {
 	///
 	/// To determine the execution weight of the calls required for
 	/// [`xcm::latest::Instruction::Transact`] instruction, `TransactionPaymentCallApi` can be used.
+	#[api_version(5)]
 	pub trait XcmPaymentApi {
 		/// Returns a list of acceptable payment assets.
 		///
@@ -65,7 +66,18 @@ sp_api::decl_runtime_apis! {
 		///   size of the message.
 		/// * `destination`: The destination to send the message to. Different destinations may use
 		///   different senders that charge different fees.
+		#[changed_in(5)]
 		fn query_delivery_fees(destination: VersionedLocation, message: VersionedXcm<()>) -> Result<VersionedAssets, Error>;
+
+		/// Get delivery fees for sending a specific `message` to a `destination`.
+		/// These always come in a specific asset, defined by the chain.
+		///
+		/// # Arguments
+		/// * `message`: The message that'll be sent, necessary because most delivery fees are based on the
+		///   size of the message.
+		/// * `destination`: The destination to send the message to. Different destinations may use
+		///   different senders that charge different fees.
+		fn query_delivery_fees(destination: VersionedLocation, message: VersionedXcm<()>, asset_id: VersionedAssetId) -> Result<VersionedAssets, Error>;
 	}
 }
 

polkadot/xcm/xcm-runtime-apis/tests/fee_estimation.rs

@@ -153,9 +153,15 @@ fn fee_estimation_for_teleport() {
 
 		let (destination, remote_messages) = forwarded_xcms_iter.next().unwrap();
 		let remote_message = &remote_messages[0];
+		let costum_asset = VersionedAssetId::from(AssetId(HereLocation::get()));
 
 		let delivery_fees = runtime_api
-			.query_delivery_fees(H256::zero(), destination.clone(), remote_message.clone())
+			.query_delivery_fees(
+				H256::zero(),
+				destination.clone(),
+				remote_message.clone(),
+				costum_asset,
+			)
 			.unwrap()
 			.unwrap();
 		assert_eq!(delivery_fees, VersionedAssets::from((Here, 20u128)));

polkadot/xcm/xcm-runtime-apis/tests/mock.rs

@@ -476,8 +476,10 @@ sp_api::mock_impl_runtime_apis! {
 			}
 		}
 
-		fn query_delivery_fees(destination: VersionedLocation, message: VersionedXcm<()>) -> Result<VersionedAssets, XcmPaymentApiError> {
-			XcmPallet::query_delivery_fees(destination, message)
+		fn query_delivery_fees(destination: VersionedLocation, message: VersionedXcm<()>, asset_id: VersionedAssetId) -> Result<VersionedAssets, XcmPaymentApiError> {
+			let delivery_fee_dot = XcmPallet::query_delivery_fees(destination, message)?;
+			quote_price_tokens_for_exact_tokens(delivery_fee_dot, asset_id)
+				.map_err(|_| XcmPaymentApiError::AssetNotFound)
 		}
 	}