Use decl_error in common runtime modules

runtime/common/src/attestations.rs

@@ -21,7 +21,9 @@
 
 use rstd::prelude::*;
 use codec::{Encode, Decode};
-use frame_support::{decl_storage, decl_module, ensure, dispatch::DispatchResult, traits::Get};
+use frame_support::{
+	decl_storage, decl_module, decl_error, ensure, dispatch::DispatchResult, traits::Get
+};
 
 use primitives::{Hash, parachain::{AttestedCandidate, CandidateReceipt, Id as ParaId}};
 use sp_runtime::RuntimeDebug;
@@ -106,13 +108,22 @@ decl_storage! {
 	}
 }
 
+decl_error! {
+	pub enum Error for Module<T: Trait> {
+		/// More attestations can be added only once in a block.
+		TooManyAttestations,
+	}
+}
+
 decl_module! {
 	/// Parachain-attestations module.
 	pub struct Module<T: Trait> for enum Call where origin: <T as system::Trait>::Origin {
+		type Error = Error<T>;
+
 		/// Provide candidate receipts for parachains, in ascending order by id.
 		fn more_attestations(origin, _more: MoreAttestations) -> DispatchResult {
 			ensure_none(origin)?;
-			ensure!(!<DidUpdate>::exists(), "More attestations can be added only once in a block.");
+			ensure!(!<DidUpdate>::exists(), Error::<T>::TooManyAttestations);
 			<DidUpdate>::put(true);
 
 			Ok(())

runtime/common/src/claims.rs

@@ -18,7 +18,7 @@
 
 use rstd::prelude::*;
 use sp_io::{hashing::keccak_256, crypto::secp256k1_ecdsa_recover};
-use frame_support::{decl_event, decl_storage, decl_module};
+use frame_support::{decl_event, decl_storage, decl_module, decl_error};
 use frame_support::weights::SimpleDispatchInfo;
 use frame_support::traits::{Currency, Get, VestingCurrency};
 use system::{ensure_root, ensure_none};
@@ -102,6 +102,15 @@ decl_event!(
 	}
 );
 
+decl_error! {
+	pub enum Error for Module<T: Trait> {
+		/// Invalid Ethereum signature.
+		InvalidEthereumSignature,
+		/// Ethereum address has no claim.
+		SignerHasNoClaim,
+	}
+}
+
 decl_storage! {
 	// A macro for the Storage trait, and its implementation, for this module.
 	// This allows for type-safe usage of the Substrate storage database, so you can
@@ -126,6 +135,8 @@ decl_storage! {
 
 decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+		type Error = Error<T>;
+
 		/// The Prefix that is used in signed Ethereum messages for this network
 		const Prefix: &[u8] = T::Prefix::get();
 
@@ -139,10 +150,10 @@ decl_module! {
 
 			let data = dest.using_encoded(to_ascii_hex);
 			let signer = Self::eth_recover(&ethereum_signature, &data)
-				.ok_or("Invalid Ethereum signature")?;
+				.ok_or(Error::<T>::InvalidEthereumSignature)?;
 
 			let balance_due = <Claims<T>>::get(&signer)
-				.ok_or("Ethereum address has no claim")?;
+				.ok_or(Error::<T>::SignerHasNoClaim)?;
 
 			// Check if this claim should have a vesting schedule.
 			if let Some(vs) = <Vesting<T>>::get(&signer) {
@@ -415,7 +426,7 @@ mod tests {
 			assert_eq!(Balances::free_balance(&42), 0);
 			assert_noop!(
 				Claims::claim(Origin::NONE, 69, sig(&bob(), &69u64.encode())),
-				"Ethereum address has no claim"
+				Error::<Test>::SignerHasNoClaim
 			);
 			assert_ok!(Claims::mint_claim(Origin::ROOT, eth(&bob()), 200, None));
 			assert_ok!(Claims::claim(Origin::NONE, 69, sig(&bob(), &69u64.encode())));
@@ -434,7 +445,7 @@ mod tests {
 			assert_eq!(Balances::free_balance(&42), 0);
 			assert_noop!(
 				Claims::claim(Origin::NONE, 69, sig(&bob(), &69u64.encode())),
-				"Ethereum address has no claim"
+				Error::<Test>::SignerHasNoClaim
 			);
 			assert_ok!(Claims::mint_claim(Origin::ROOT, eth(&bob()), 200, Some((50, 10, 1))));
 			assert_ok!(Claims::claim(Origin::NONE, 69, sig(&bob(), &69u64.encode())));
@@ -459,23 +470,32 @@ mod tests {
 		new_test_ext().execute_with(|| {
 			assert_eq!(Balances::free_balance(&42), 0);
 			assert_ok!(Claims::claim(Origin::NONE, 42, sig(&alice(), &42u64.encode())));
-			assert_noop!(Claims::claim(Origin::NONE, 42, sig(&alice(), &42u64.encode())), "Ethereum address has no claim");
+			assert_noop!(
+				Claims::claim(Origin::NONE, 42, sig(&alice(), &42u64.encode())),
+				Error::<Test>::SignerHasNoClaim
+			);
 		});
 	}
 
 	#[test]
 	fn non_sender_sig_doesnt_work() {
 		new_test_ext().execute_with(|| {
 			assert_eq!(Balances::free_balance(&42), 0);
-			assert_noop!(Claims::claim(Origin::NONE, 42, sig(&alice(), &69u64.encode())), "Ethereum address has no claim");
+			assert_noop!(
+				Claims::claim(Origin::NONE, 42, sig(&alice(), &69u64.encode())),
+				Error::<Test>::SignerHasNoClaim
+			);
 		});
 	}
 
 	#[test]
 	fn non_claimant_doesnt_work() {
 		new_test_ext().execute_with(|| {
 			assert_eq!(Balances::free_balance(&42), 0);
-			assert_noop!(Claims::claim(Origin::NONE, 42, sig(&bob(), &69u64.encode())), "Ethereum address has no claim");
+			assert_noop!(
+				Claims::claim(Origin::NONE, 42, sig(&bob(), &69u64.encode())),
+				Error::<Test>::SignerHasNoClaim
+			);
 		});
 	}