pr feedback

parachain/pallets/outbound-queue/src/lib.rs

@@ -429,7 +429,7 @@ pub mod pallet {
 			fee_per_gas.saturating_mul(max_gas_required.into()).saturating_add(reward)
 		}
 
-		/// Calculate fee in native currency for processing a message locally
+		/// The local component of the message processing fees in native currency
 		pub(crate) fn calculate_local_fee() -> T::Balance {
 			T::WeightToFee::weight_to_fee(
 				&T::WeightInfo::do_process_message().saturating_add(T::WeightInfo::commit_single()),

parachain/pallets/outbound-queue/src/send_message_impl.rs

@@ -8,7 +8,7 @@ use frame_support::{
 };
 use snowbridge_core::outbound::{
 	AggregateMessageOrigin, ExportOrigin, Fee, Message, QueuedMessage, SendError, SendMessage,
-	SendMessageFee, VersionedQueuedMessage,
+	SendMessageFeeProvider, VersionedQueuedMessage,
 };
 use sp_core::H256;
 use sp_runtime::BoundedVec;
@@ -26,9 +26,10 @@ pub struct Ticket<MaxMessageSize: Get<u32>> {
 
 impl<T: Config> SendMessage for Pallet<T> {
 	type Ticket = Ticket<MaxEnqueuedMessageSizeOf<T>>;
-	type Balance = T::Balance;
 
-	fn validate(message: &Message) -> Result<(Self::Ticket, Fee<Self::Balance>), SendError> {
+	fn validate(
+		message: &Message,
+	) -> Result<(Self::Ticket, Fee<<Self as SendMessageFeeProvider>::Balance>), SendError> {
 		// The inner payload should not be too large
 		let payload = message.command.abi_encode();
 
@@ -84,10 +85,10 @@ impl<T: Config> SendMessage for Pallet<T> {
 	}
 }
 
-impl<T: Config> SendMessageFee for Pallet<T> {
+impl<T: Config> SendMessageFeeProvider for Pallet<T> {
 	type Balance = T::Balance;
 
-	/// Calculate fee in native currency for processing a message locally
+	/// The local component of the message processing fees in native currency
 	fn local_fee() -> Self::Balance {
 		Self::calculate_local_fee()
 	}

parachain/primitives/core/src/outbound.rs

@@ -278,24 +278,25 @@ where
 }
 
 /// A trait for sending messages to Ethereum
-pub trait SendMessage {
+pub trait SendMessage: SendMessageFeeProvider {
 	type Ticket: Clone + Encode + Decode;
-	type Balance: BaseArithmetic + Unsigned + Copy;
 
 	/// Validate an outbound message and return a tuple:
 	/// 1. Ticket for submitting the message
 	/// 2. Delivery fee
-	fn validate(message: &Message) -> Result<(Self::Ticket, Fee<Self::Balance>), SendError>;
+	fn validate(
+		message: &Message,
+	) -> Result<(Self::Ticket, Fee<<Self as SendMessageFeeProvider>::Balance>), SendError>;
 
 	/// Submit the message ticket for eventual delivery to Ethereum
 	fn deliver(ticket: Self::Ticket) -> Result<H256, SendError>;
 }
 
 /// A trait for getting the local costs associated with sending a message.
-pub trait SendMessageFee {
+pub trait SendMessageFeeProvider {
 	type Balance: BaseArithmetic + Unsigned + Copy;
 
-	/// Calculate fee in native currency for processing a message locally
+	/// The local component of the message processing fees in native currency
 	fn local_fee() -> Self::Balance;
 }