override conversion rate in estimate-message-fee RPC (#1189)

bridges/bin/millau/runtime/src/lib.rs

@@ -52,7 +52,7 @@ use sp_runtime::{
 	create_runtime_str, generic, impl_opaque_keys,
 	traits::{Block as BlockT, IdentityLookup, Keccak256, NumberFor, OpaqueKeys},
 	transaction_validity::{TransactionSource, TransactionValidity},
-	ApplyExtrinsicResult, FixedPointNumber, MultiSignature, MultiSigner, Perquintill,
+	ApplyExtrinsicResult, FixedPointNumber, FixedU128, MultiSignature, MultiSigner, Perquintill,
 };
 use sp_std::prelude::*;
 #[cfg(feature = "std")]
@@ -744,10 +744,12 @@ impl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			_lane_id: bp_messages::LaneId,
 			payload: ToRialtoMessagePayload,
+			rialto_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<Balance> {
 			estimate_message_dispatch_and_delivery_fee::<WithRialtoMessageBridge>(
 				&payload,
 				WithRialtoMessageBridge::RELAYER_FEE_PERCENT,
+				rialto_to_this_conversion_rate,
 			).ok()
 		}
 

bridges/bin/millau/runtime/src/rialto_messages.rs

@@ -91,11 +91,14 @@ impl MessageBridge for WithRialtoMessageBridge {
 	type ThisChain = Millau;
 	type BridgedChain = Rialto;
 
-	fn bridged_balance_to_this_balance(bridged_balance: bp_rialto::Balance) -> bp_millau::Balance {
-		bp_millau::Balance::try_from(
-			RialtoToMillauConversionRate::get().saturating_mul_int(bridged_balance),
-		)
-		.unwrap_or(bp_millau::Balance::MAX)
+	fn bridged_balance_to_this_balance(
+		bridged_balance: bp_rialto::Balance,
+		bridged_to_this_conversion_rate_override: Option<FixedU128>,
+	) -> bp_millau::Balance {
+		let conversion_rate = bridged_to_this_conversion_rate_override
+			.unwrap_or_else(|| RialtoToMillauConversionRate::get());
+		bp_millau::Balance::try_from(conversion_rate.saturating_mul_int(bridged_balance))
+			.unwrap_or(bp_millau::Balance::MAX)
 	}
 }