error handling

bin/node/runtime/src/lib.rs

@@ -52,6 +52,7 @@ use pallet_grandpa::{
 	fg_primitives, AuthorityId as GrandpaId, AuthorityList as GrandpaAuthorityList,
 };
 use pallet_im_online::sr25519::AuthorityId as ImOnlineId;
+use pallet_nomination_pools_rpc_runtime_api::NpApiError;
 use pallet_session::historical::{self as pallet_session_historical};
 pub use pallet_transaction_payment::{CurrencyAdapter, Multiplier, TargetedFeeAdjustment};
 use pallet_transaction_payment::{FeeDetails, RuntimeDispatchInfo};
@@ -1836,10 +1837,11 @@ impl_runtime_apis! {
 	}
 
 	impl pallet_nomination_pools_rpc_runtime_api::NominationPoolsApi<Block, AccountId, Balance> for Runtime {
-		fn pending_rewards(member_account: AccountId) -> Balance {
-			let member = pallet_nomination_pools::PoolMembers::<Runtime>::get(member_account).unwrap();
-
-			member.pending_rewards(member.last_recorded_reward_counter).unwrap()
+		fn pending_rewards(member_account: AccountId) -> Result<Balance, NpApiError> {
+			if let Some(member) = pallet_nomination_pools::PoolMembers::<Runtime>::get(member_account) {
+				return member.pending_rewards(member.last_recorded_reward_counter).map_err(|_| NpApiError::OverflowInPendingRewards);
+			}
+			Err(NpApiError::MemberNotFound)
 		}
 	}
 

frame/nomination-pools/rpc/runtime-api/src/lib.rs

@@ -19,14 +19,23 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use codec::Codec;
+use codec::{Codec, Decode, Encode};
 pub use pallet_nomination_pools::PoolId;
 
+/// The possible errors that may occur when getting the pending rewards.
+#[derive(Decode, Encode, Eq, PartialEq)]
+pub enum NpApiError {
+	/// The member was not found.
+	MemberNotFound,
+	/// An overflow occured when calculating the pending rewards.
+	OverflowInPendingRewards,
+}
+
 sp_api::decl_runtime_apis! {
 	pub trait NominationPoolsApi<AccountId, Balance>
 		where AccountId: Codec, Balance: Codec
 	{
 		/// Returns the pending rewards for the given member.
-		fn pending_rewards(member: AccountId) -> Balance;
+		fn pending_rewards(member: AccountId) -> Result<Balance, NpApiError>;
 	}
 }

frame/nomination-pools/rpc/src/lib.rs

@@ -22,6 +22,7 @@ use codec::Codec;
 use jsonrpc_core::Error;
 use jsonrpc_derive::rpc;
 pub use pallet_nomination_pools_rpc_runtime_api::NominationPoolsApi as NominationPoolsRuntimeApi;
+use pallet_nomination_pools_rpc_runtime_api::NpApiError;
 use sp_api::ProvideRuntimeApi;
 use sp_blockchain::HeaderBackend;
 use sp_runtime::{generic::BlockId, traits::Block as BlockT};
@@ -65,10 +66,19 @@ where
 		let api = self.client.runtime_api();
 		let at = BlockId::hash(at.unwrap_or_else(|| self.client.info().best_hash));
 
-		api.pending_rewards(&at, member).map_err(|e| Error {
-			code: jsonrpc_core::ErrorCode::ServerError(1),
-			message: format!("{:?}", e),
-			data: None,
+		api.pending_rewards(&at, member).map_err(|e| -> Error {
+			match e {
+				NpApiError::MemberNotFound => Error {
+					code: jsonrpc_core::ErrorCode::ServerError(1),
+					message: format!("Member with the given account was not found."),
+					data: None,
+				},
+				NpApiError::OverflowInPendingRewards => Error {
+					code: jsonrpc_core::ErrorCode::ServerError(2),
+					message: format!("An overflow occured when calculating the pending rewards."),
+					data: None,
+				},
+			}
 		})
 	}
 }