fix: handle breaking change in monitoring.

state-chain/custom-rpc/src/monitoring.rs

@@ -4,6 +4,7 @@ use crate::{
 use cf_chains::{dot::PolkadotAccountId, sol::SolAddress};
 use jsonrpsee::{core::RpcResult, proc_macros::rpc};
 use sc_client_api::{BlockchainEvents, HeaderBackend};
+use serde::{Deserialize, Serialize};
 use sp_core::{bounded_vec::BoundedVec, ConstU32};
 use state_chain_runtime::{
 	chainflip::Offence,
@@ -14,6 +15,25 @@ use state_chain_runtime::{
 	},
 };
 
+// Temporary struct to hold the deprecated blocks_per_epoch field.
+// Can be deleted after v1.7 is released (meaning: after the version is bumped to 1.8).
+#[derive(Serialize, Deserialize)]
+pub struct RpcEpochState {
+	#[deprecated(
+		since = "1.8.0",
+		note = "This field is deprecated and will be removed in v1.8. Use blocks_per_epoch instead."
+	)]
+	blocks_per_epoch: u32,
+	#[serde(flatten)]
+	epoch_state: EpochState,
+}
+
+impl From<EpochState> for RpcEpochState {
+	fn from(epoch_state: EpochState) -> Self {
+		Self { blocks_per_epoch: epoch_state.epoch_duration, epoch_state }
+	}
+}
+
 #[rpc(server, client, namespace = "cf_monitoring")]
 pub trait MonitoringApi {
 	#[method(name = "authorities")]
@@ -33,7 +53,7 @@ pub trait MonitoringApi {
 		at: Option<state_chain_runtime::Hash>,
 	) -> RpcResult<Vec<(Offence, u32)>>;
 	#[method(name = "epoch_state")]
-	fn cf_epoch_state(&self, at: Option<state_chain_runtime::Hash>) -> RpcResult<EpochState>;
+	fn cf_epoch_state(&self, at: Option<state_chain_runtime::Hash>) -> RpcResult<RpcEpochState>;
 	#[method(name = "redemptions")]
 	fn cf_redemptions(&self, at: Option<state_chain_runtime::Hash>) -> RpcResult<RedemptionsInfo>;
 	#[method(name = "pending_broadcasts")]
@@ -86,13 +106,14 @@ pub trait MonitoringApi {
 }
 
 macro_rules! pass_through {
-	($( $name:ident -> $result_type:ty ),+) => {
+	($( $name:ident -> $result_type:ty $([with: $map_fn:expr])? ),+) => {
 
 		$(
 			fn $name(&self, at: Option<state_chain_runtime::Hash>) -> RpcResult<$result_type> {
 				self.client
 					.runtime_api()
 					.$name(self.unwrap_or_best(at))
+					$( .map($map_fn) )?
 					.map_err(to_rpc_error)
 			}
 		)+
@@ -116,7 +137,7 @@ where
 		cf_btc_utxos -> BtcUtxos,
 		cf_dot_aggkey -> PolkadotAccountId,
 		cf_suspended_validators -> Vec<(Offence, u32)>,
-		cf_epoch_state -> EpochState,
+		cf_epoch_state -> RpcEpochState [with: RpcEpochState::from],
 		cf_redemptions -> RedemptionsInfo,
 		cf_pending_broadcasts_count -> PendingBroadcasts,
 		cf_pending_tss_ceremonies_count -> PendingTssCeremonies,