From 4fffe19c2829d3248e06d4258169d9509de27b3a Mon Sep 17 00:00:00 2001
From: Shawn Tabrizi <shawntabrizi@gmail.com>
Date: Fri, 20 Dec 2019 00:23:20 +0100
Subject: [PATCH] Update Balances Pallet for `decl_error!` (#4405)

* Update balances for `decl_error!`

* Update for new `decl_error`

* Fix staking tests

* Use `ok_or` over `match`
---
 substrate/frame/balances/src/lib.rs   | 52 +++++++++++-------
 substrate/frame/balances/src/mock.rs  | 22 ++++----
 substrate/frame/balances/src/tests.rs | 78 +++++++++++++--------------
 substrate/frame/staking/src/lib.rs    |  2 +-
 substrate/frame/staking/src/tests.rs  | 42 ++++++++++++---
 5 files changed, 120 insertions(+), 76 deletions(-)

diff --git a/substrate/frame/balances/src/lib.rs b/substrate/frame/balances/src/lib.rs
index 4b53f718981..1b89ae2b16a 100644
--- a/substrate/frame/balances/src/lib.rs
+++ b/substrate/frame/balances/src/lib.rs
@@ -163,7 +163,7 @@ use sp_std::prelude::*;
 use sp_std::{cmp, result, mem, fmt::Debug};
 use codec::{Codec, Encode, Decode};
 use frame_support::{
-	StorageValue, Parameter, decl_event, decl_storage, decl_module,
+	StorageValue, Parameter, decl_event, decl_storage, decl_module, decl_error,
 	traits::{
 		UpdateBalanceOutcome, Currency, OnFreeBalanceZero, OnUnbalanced, TryDrop,
 		WithdrawReason, WithdrawReasons, LockIdentifier, LockableCurrency, ExistenceRequirement,
@@ -272,6 +272,27 @@ decl_event!(
 	}
 );
 
+decl_error! {
+	pub enum Error for Module<T: Trait<I>, I: Instance> {
+		/// Vesting balance too high to send value
+		VestingBalance,
+		/// Account liquidity restrictions prevent withdrawal
+		LiquidityRestrictions,
+		/// Got an overflow after adding
+		Overflow,
+		/// Balance too low to send value
+		InsufficientBalance,
+		/// Value too low to create account due to existential deposit
+		ExistentialDeposit,
+		/// Transfer/payment would kill account
+		KeepAlive,
+		/// A vesting schedule already exists for this account
+		ExistingVestingSchedule,
+		/// Beneficiary account must pre-exist
+		DeadAccount,
+	}
+}
+
 /// Struct to encode the vesting schedule of an individual account.
 #[derive(Encode, Decode, Copy, Clone, PartialEq, Eq, RuntimeDebug)]
 pub struct VestingSchedule<Balance, BlockNumber> {
@@ -390,6 +411,8 @@ decl_storage! {
 
 decl_module! {
 	pub struct Module<T: Trait<I>, I: Instance = DefaultInstance> for enum Call where origin: T::Origin {
+		type Error = Error<T, I>;
+
 		/// The minimum amount required to keep an account open.
 		const ExistentialDeposit: T::Balance = T::ExistentialDeposit::get();
 
@@ -897,7 +920,7 @@ where
 		if reasons.intersects(WithdrawReason::Reserve | WithdrawReason::Transfer)
 			&& Self::vesting_balance(who) > new_balance
 		{
-			Err("vesting balance too high to send value")?
+			Err(Error::<T, I>::VestingBalance)?
 		}
 		let locks = Self::locks(who);
 		if locks.is_empty() {
@@ -914,7 +937,7 @@ where
 		{
 			Ok(())
 		} else {
-			Err("account liquidity restrictions prevent withdrawal".into())
+			Err(Error::<T, I>::LiquidityRestrictions.into())
 		}
 	}
 
@@ -928,31 +951,22 @@ where
 		let to_balance = Self::free_balance(dest);
 		let would_create = to_balance.is_zero();
 		let fee = if would_create { T::CreationFee::get() } else { T::TransferFee::get() };
-		let liability = match value.checked_add(&fee) {
-			Some(l) => l,
-			None => Err("got overflow after adding a fee to value")?,
-		};
+		let liability = value.checked_add(&fee).ok_or(Error::<T, I>::Overflow)?;
+		let new_from_balance = from_balance.checked_sub(&liability).ok_or(Error::<T, I>::InsufficientBalance)?;
 
-		let new_from_balance = match from_balance.checked_sub(&liability) {
-			None => Err("balance too low to send value")?,
-			Some(b) => b,
-		};
 		if would_create && value < T::ExistentialDeposit::get() {
-			Err("value too low to create account")?
+			Err(Error::<T, I>::ExistentialDeposit)?
 		}
 		Self::ensure_can_withdraw(transactor, value, WithdrawReason::Transfer.into(), new_from_balance)?;
 
 		// NOTE: total stake being stored in the same type means that this could never overflow
 		// but better to be safe than sorry.
-		let new_to_balance = match to_balance.checked_add(&value) {
-			Some(b) => b,
-			None => Err("destination balance too high to receive value")?,
-		};
+		let new_to_balance = to_balance.checked_add(&value).ok_or(Error::<T, I>::Overflow)?;
 
 		if transactor != dest {
 			if existence_requirement == ExistenceRequirement::KeepAlive {
 				if new_from_balance < Self::minimum_balance() {
-					Err("transfer would kill account")?
+					Err(Error::<T, I>::KeepAlive)?
 				}
 			}
 
@@ -1026,7 +1040,7 @@ where
 		value: Self::Balance
 	) -> result::Result<Self::PositiveImbalance, DispatchError> {
 		if Self::total_balance(who).is_zero() {
-			Err("beneficiary account must pre-exist")?
+			Err(Error::<T, I>::DeadAccount)?
 		}
 		Self::set_free_balance(who, Self::free_balance(who) + value);
 		Ok(PositiveImbalance::new(value))
@@ -1143,7 +1157,7 @@ where
 		value: Self::Balance,
 	) -> result::Result<Self::Balance, DispatchError> {
 		if Self::total_balance(beneficiary).is_zero() {
-			Err("beneficiary account must pre-exist")?
+			Err(Error::<T, I>::DeadAccount)?
 		}
 		let b = Self::reserved_balance(slashed);
 		let slash = cmp::min(b, value);
diff --git a/substrate/frame/balances/src/mock.rs b/substrate/frame/balances/src/mock.rs
index c54165d6ec0..f5664be7e85 100644
--- a/substrate/frame/balances/src/mock.rs
+++ b/substrate/frame/balances/src/mock.rs
@@ -27,7 +27,7 @@ use crate::{GenesisConfig, Module, Trait};
 
 use frame_system as system;
 impl_outer_origin!{
-	pub enum Origin for Runtime {}
+	pub enum Origin for Test {}
 }
 
 thread_local! {
@@ -53,14 +53,14 @@ impl Get<u64> for CreationFee {
 
 // Workaround for https://github.com/rust-lang/rust/issues/26925 . Remove when sorted.
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub struct Runtime;
+pub struct Test;
 parameter_types! {
 	pub const BlockHashCount: u64 = 250;
 	pub const MaximumBlockWeight: Weight = 1024;
 	pub const MaximumBlockLength: u32 = 2 * 1024;
 	pub const AvailableBlockRatio: Perbill = Perbill::one();
 }
-impl frame_system::Trait for Runtime {
+impl frame_system::Trait for Test {
 	type Origin = Origin;
 	type Index = u64;
 	type BlockNumber = u64;
@@ -82,15 +82,15 @@ parameter_types! {
 	pub const TransactionBaseFee: u64 = 0;
 	pub const TransactionByteFee: u64 = 1;
 }
-impl pallet_transaction_payment::Trait for Runtime {
-	type Currency = Module<Runtime>;
+impl pallet_transaction_payment::Trait for Test {
+	type Currency = Module<Test>;
 	type OnTransactionPayment = ();
 	type TransactionBaseFee = TransactionBaseFee;
 	type TransactionByteFee = TransactionByteFee;
 	type WeightToFee = ConvertInto;
 	type FeeMultiplierUpdate = ();
 }
-impl Trait for Runtime {
+impl Trait for Test {
 	type Balance = u64;
 	type OnFreeBalanceZero = ();
 	type OnNewAccount = ();
@@ -152,8 +152,8 @@ impl ExtBuilder {
 	}
 	pub fn build(self) -> sp_io::TestExternalities {
 		self.set_associated_consts();
-		let mut t = frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap();
-		GenesisConfig::<Runtime> {
+		let mut t = frame_system::GenesisConfig::default().build_storage::<Test>().unwrap();
+		GenesisConfig::<Test> {
 			balances: if self.monied {
 				vec![
 					(1, 10 * self.existential_deposit),
@@ -179,10 +179,10 @@ impl ExtBuilder {
 	}
 }
 
-pub type System = frame_system::Module<Runtime>;
-pub type Balances = Module<Runtime>;
+pub type System = frame_system::Module<Test>;
+pub type Balances = Module<Test>;
 
-pub const CALL: &<Runtime as frame_system::Trait>::Call = &();
+pub const CALL: &<Test as frame_system::Trait>::Call = &();
 
 /// create a transaction info struct from weight. Handy to avoid building the whole struct.
 pub fn info_from_weight(w: Weight) -> DispatchInfo {
diff --git a/substrate/frame/balances/src/tests.rs b/substrate/frame/balances/src/tests.rs
index fe0df11b3a0..d5cf35a212b 100644
--- a/substrate/frame/balances/src/tests.rs
+++ b/substrate/frame/balances/src/tests.rs
@@ -17,7 +17,7 @@
 //! Tests for the module.
 
 use super::*;
-use mock::{Balances, ExtBuilder, Runtime, System, info_from_weight, CALL};
+use mock::{Balances, ExtBuilder, Test, System, info_from_weight, CALL};
 use sp_runtime::traits::{SignedExtension, BadOrigin};
 use frame_support::{
 	assert_noop, assert_ok, assert_err,
@@ -38,7 +38,7 @@ fn basic_locking_should_work() {
 		Balances::set_lock(ID_1, &1, 9, u64::max_value(), WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 5, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 	});
 }
@@ -94,17 +94,17 @@ fn lock_value_extension_should_work() {
 		Balances::set_lock(ID_1, &1, 5, u64::max_value(), WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 6, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 		Balances::extend_lock(ID_1, &1, 2, u64::max_value(), WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 6, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 		Balances::extend_lock(ID_1, &1, 8, u64::max_value(), WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 3, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 	});
 }
@@ -119,11 +119,11 @@ fn lock_reasons_should_work() {
 			Balances::set_lock(ID_1, &1, 10, u64::max_value(), WithdrawReason::Transfer.into());
 			assert_noop!(
 				<Balances as Currency<_>>::transfer(&1, &2, 1, AllowDeath),
-				"account liquidity restrictions prevent withdrawal"
+				Error::<Test, _>::LiquidityRestrictions
 			);
 			assert_ok!(<Balances as ReservableCurrency<_>>::reserve(&1, 1));
 			// NOTE: this causes a fee payment.
-			assert!(<ChargeTransactionPayment<Runtime> as SignedExtension>::pre_dispatch(
+			assert!(<ChargeTransactionPayment<Test> as SignedExtension>::pre_dispatch(
 				ChargeTransactionPayment::from(1),
 				&1,
 				CALL,
@@ -135,9 +135,9 @@ fn lock_reasons_should_work() {
 			assert_ok!(<Balances as Currency<_>>::transfer(&1, &2, 1, AllowDeath));
 			assert_noop!(
 				<Balances as ReservableCurrency<_>>::reserve(&1, 1),
-				"account liquidity restrictions prevent withdrawal"
+				Error::<Test, _>::LiquidityRestrictions
 			);
-			assert!(<ChargeTransactionPayment<Runtime> as SignedExtension>::pre_dispatch(
+			assert!(<ChargeTransactionPayment<Test> as SignedExtension>::pre_dispatch(
 				ChargeTransactionPayment::from(1),
 				&1,
 				CALL,
@@ -148,7 +148,7 @@ fn lock_reasons_should_work() {
 			Balances::set_lock(ID_1, &1, 10, u64::max_value(), WithdrawReason::TransactionPayment.into());
 			assert_ok!(<Balances as Currency<_>>::transfer(&1, &2, 1, AllowDeath));
 			assert_ok!(<Balances as ReservableCurrency<_>>::reserve(&1, 1));
-			assert!(<ChargeTransactionPayment<Runtime> as SignedExtension>::pre_dispatch(
+			assert!(<ChargeTransactionPayment<Test> as SignedExtension>::pre_dispatch(
 				ChargeTransactionPayment::from(1),
 				&1,
 				CALL,
@@ -164,7 +164,7 @@ fn lock_block_number_should_work() {
 		Balances::set_lock(ID_1, &1, 10, 2, WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 1, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 
 		System::set_block_number(2);
@@ -178,18 +178,18 @@ fn lock_block_number_extension_should_work() {
 		Balances::set_lock(ID_1, &1, 10, 2, WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 6, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 		Balances::extend_lock(ID_1, &1, 10, 1, WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 6, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 		System::set_block_number(2);
 		Balances::extend_lock(ID_1, &1, 10, 8, WithdrawReasons::all());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 3, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 	});
 }
@@ -200,17 +200,17 @@ fn lock_reasons_extension_should_work() {
 		Balances::set_lock(ID_1, &1, 10, 10, WithdrawReason::Transfer.into());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 6, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 		Balances::extend_lock(ID_1, &1, 10, 10, WithdrawReasons::none());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 6, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 		Balances::extend_lock(ID_1, &1, 10, 10, WithdrawReason::Reserve.into());
 		assert_noop!(
 			<Balances as Currency<_>>::transfer(&1, &2, 6, AllowDeath),
-			"account liquidity restrictions prevent withdrawal"
+			Error::<Test, _>::LiquidityRestrictions
 		);
 	});
 }
@@ -227,7 +227,7 @@ fn default_indexing_on_new_accounts_should_not_work2() {
 			// ext_deposit is 10, value is 9, not satisfies for ext_deposit
 			assert_noop!(
 				Balances::transfer(Some(1).into(), 5, 9),
-				"value too low to create account",
+				Error::<Test, _>::ExistentialDeposit,
 			);
 			assert_eq!(Balances::is_dead_account(&5), true); // account 5 should not exist
 			assert_eq!(Balances::free_balance(&1), 100);
@@ -277,7 +277,7 @@ fn reward_should_work() {
 		assert_eq!(Balances::total_balance(&1), 10);
 		assert_ok!(Balances::deposit_into_existing(&1, 10).map(drop));
 		assert_eq!(Balances::total_balance(&1), 20);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 120);
+		assert_eq!(<TotalIssuance<Test>>::get(), 120);
 	});
 }
 
@@ -379,7 +379,7 @@ fn balance_transfer_when_reserved_should_not_work() {
 		assert_ok!(Balances::reserve(&1, 69));
 		assert_noop!(
 			Balances::transfer(Some(1).into(), 2, 69),
-			"balance too low to send value",
+			Error::<Test, _>::InsufficientBalance,
 		);
 	});
 }
@@ -412,7 +412,7 @@ fn slashing_balance_should_work() {
 		assert!(Balances::slash(&1, 69).1.is_zero());
 		assert_eq!(Balances::free_balance(&1), 0);
 		assert_eq!(Balances::reserved_balance(&1), 42);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 42);
+		assert_eq!(<TotalIssuance<Test>>::get(), 42);
 	});
 }
 
@@ -424,7 +424,7 @@ fn slashing_incomplete_balance_should_work() {
 		assert_eq!(Balances::slash(&1, 69).1, 27);
 		assert_eq!(Balances::free_balance(&1), 0);
 		assert_eq!(Balances::reserved_balance(&1), 0);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 0);
+		assert_eq!(<TotalIssuance<Test>>::get(), 0);
 	});
 }
 
@@ -447,7 +447,7 @@ fn slashing_reserved_balance_should_work() {
 		assert_eq!(Balances::slash_reserved(&1, 42).1, 0);
 		assert_eq!(Balances::reserved_balance(&1), 69);
 		assert_eq!(Balances::free_balance(&1), 0);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 69);
+		assert_eq!(<TotalIssuance<Test>>::get(), 69);
 	});
 }
 
@@ -459,7 +459,7 @@ fn slashing_incomplete_reserved_balance_should_work() {
 		assert_eq!(Balances::slash_reserved(&1, 69).1, 27);
 		assert_eq!(Balances::free_balance(&1), 69);
 		assert_eq!(Balances::reserved_balance(&1), 0);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 69);
+		assert_eq!(<TotalIssuance<Test>>::get(), 69);
 	});
 }
 
@@ -482,7 +482,7 @@ fn transferring_reserved_balance_to_nonexistent_should_fail() {
 	ExtBuilder::default().build().execute_with(|| {
 		let _ = Balances::deposit_creating(&1, 111);
 		assert_ok!(Balances::reserve(&1, 111));
-		assert_noop!(Balances::repatriate_reserved(&1, &2, 42), "beneficiary account must pre-exist");
+		assert_noop!(Balances::repatriate_reserved(&1, &2, 42), Error::<Test, _>::DeadAccount);
 	});
 }
 
@@ -503,12 +503,12 @@ fn transferring_incomplete_reserved_balance_should_work() {
 #[test]
 fn transferring_too_high_value_should_not_panic() {
 	ExtBuilder::default().build().execute_with(|| {
-		<FreeBalance<Runtime>>::insert(1, u64::max_value());
-		<FreeBalance<Runtime>>::insert(2, 1);
+		<FreeBalance<Test>>::insert(1, u64::max_value());
+		<FreeBalance<Test>>::insert(2, 1);
 
 		assert_err!(
 			Balances::transfer(Some(1).into(), 2, u64::max_value()),
-			"destination balance too high to receive value",
+			Error::<Test, _>::Overflow,
 		);
 
 		assert_eq!(Balances::free_balance(&1), u64::max_value());
@@ -520,12 +520,12 @@ fn transferring_too_high_value_should_not_panic() {
 fn account_create_on_free_too_low_with_other() {
 	ExtBuilder::default().existential_deposit(100).build().execute_with(|| {
 		let _ = Balances::deposit_creating(&1, 100);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 100);
+		assert_eq!(<TotalIssuance<Test>>::get(), 100);
 
 		// No-op.
 		let _ = Balances::deposit_creating(&2, 50);
 		assert_eq!(Balances::free_balance(&2), 0);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 100);
+		assert_eq!(<TotalIssuance<Test>>::get(), 100);
 	})
 }
 
@@ -536,14 +536,14 @@ fn account_create_on_free_too_low() {
 		// No-op.
 		let _ = Balances::deposit_creating(&2, 50);
 		assert_eq!(Balances::free_balance(&2), 0);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 0);
+		assert_eq!(<TotalIssuance<Test>>::get(), 0);
 	})
 }
 
 #[test]
 fn account_removal_on_free_too_low() {
 	ExtBuilder::default().existential_deposit(100).build().execute_with(|| {
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 0);
+		assert_eq!(<TotalIssuance<Test>>::get(), 0);
 
 		// Setup two accounts with free balance above the existential threshold.
 		let _ = Balances::deposit_creating(&1, 110);
@@ -551,7 +551,7 @@ fn account_removal_on_free_too_low() {
 
 		assert_eq!(Balances::free_balance(&1), 110);
 		assert_eq!(Balances::free_balance(&2), 110);
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 220);
+		assert_eq!(<TotalIssuance<Test>>::get(), 220);
 
 		// Transfer funds from account 1 of such amount that after this transfer
 		// the balance of account 1 will be below the existential threshold.
@@ -563,7 +563,7 @@ fn account_removal_on_free_too_low() {
 		assert_eq!(Balances::free_balance(&2), 130);
 
 		// Verify that TotalIssuance tracks balance removal when free balance is too low.
-		assert_eq!(<TotalIssuance<Runtime>>::get(), 130);
+		assert_eq!(<TotalIssuance<Test>>::get(), 130);
 	});
 }
 
@@ -575,7 +575,7 @@ fn transfer_overflow_isnt_exploitable() {
 
 		assert_err!(
 			Balances::transfer(Some(1).into(), 5, evil_value),
-			"got overflow after adding a fee to value",
+			Error::<Test, _>::Overflow,
 		);
 	});
 }
@@ -656,7 +656,7 @@ fn unvested_balance_should_not_transfer() {
 			assert_eq!(Balances::vesting_balance(&1), 45);
 			assert_noop!(
 				Balances::transfer(Some(1).into(), 2, 56),
-				"vesting balance too high to send value",
+				Error::<Test, _>::VestingBalance,
 			); // Account 1 cannot send more than vested amount
 		});
 }
@@ -751,7 +751,7 @@ fn transfer_keep_alive_works() {
 		let _ = Balances::deposit_creating(&1, 100);
 		assert_err!(
 			Balances::transfer_keep_alive(Some(1).into(), 2, 100),
-			"transfer would kill account"
+			Error::<Test, _>::KeepAlive
 		);
 		assert_eq!(Balances::is_dead_account(&1), false);
 		assert_eq!(Balances::total_balance(&1), 100);
@@ -763,8 +763,8 @@ fn transfer_keep_alive_works() {
 #[should_panic="the balance of any account should always be more than existential deposit."]
 fn cannot_set_genesis_value_below_ed() {
 	mock::EXISTENTIAL_DEPOSIT.with(|v| *v.borrow_mut() = 11);
-	let mut t = frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap();
-	let _ = GenesisConfig::<Runtime> {
+	let mut t = frame_system::GenesisConfig::default().build_storage::<Test>().unwrap();
+	let _ = GenesisConfig::<Test> {
 		balances: vec![(1, 10)],
 		vesting: vec![],
 	}.assimilate_storage(&mut t).unwrap();
diff --git a/substrate/frame/staking/src/lib.rs b/substrate/frame/staking/src/lib.rs
index 2acbe28a0ae..f8cdd270591 100644
--- a/substrate/frame/staking/src/lib.rs
+++ b/substrate/frame/staking/src/lib.rs
@@ -784,7 +784,7 @@ decl_event!(
 );
 
 decl_error! {
-	/// Error for the stacking module.
+	/// Error for the staking module.
 	pub enum Error for Module<T: Trait> {
 		/// Not a controller account.
 		NotController,
diff --git a/substrate/frame/staking/src/tests.rs b/substrate/frame/staking/src/tests.rs
index 109f2e086f6..9bb10610a08 100644
--- a/substrate/frame/staking/src/tests.rs
+++ b/substrate/frame/staking/src/tests.rs
@@ -20,7 +20,11 @@ use super::*;
 use mock::*;
 use sp_runtime::{assert_eq_error_rate, traits::{OnInitialize, BadOrigin}};
 use sp_staking::offence::OffenceDetails;
-use frame_support::{assert_ok, assert_noop, traits::{Currency, ReservableCurrency}};
+use frame_support::{
+	assert_ok, assert_noop,
+	traits::{Currency, ReservableCurrency},
+	dispatch::DispatchError,
+};
 use substrate_test_utils::assert_eq_uvec;
 
 #[test]
@@ -32,7 +36,11 @@ fn force_unstake_works() {
 		// Cant transfer
 		assert_noop!(
 			Balances::transfer(Origin::signed(11), 1, 10),
-			"account liquidity restrictions prevent withdrawal"
+			DispatchError::Module {
+				index: 0,
+				error: 1,
+				message: Some("LiquidityRestrictions"),
+			}
 		);
 		// Force unstake requires root.
 		assert_noop!(Staking::force_unstake(Origin::signed(11), 11), BadOrigin);
@@ -326,7 +334,14 @@ fn staking_should_work() {
 				Some(StakingLedger { stash: 3, total: 1500, active: 1500, unlocking: vec![] })
 			);
 			// e.g. it cannot spend more than 500 that it has free from the total 2000
-			assert_noop!(Balances::reserve(&3, 501), "account liquidity restrictions prevent withdrawal");
+			assert_noop!(
+				Balances::reserve(&3, 501),
+				DispatchError::Module {
+					index: 0,
+					error: 1,
+					message: Some("LiquidityRestrictions"),
+				}
+			);
 			assert_ok!(Balances::reserve(&3, 409));
 		});
 }
@@ -817,7 +832,11 @@ fn cannot_transfer_staked_balance() {
 		// Confirm account 11 cannot transfer as a result
 		assert_noop!(
 			Balances::transfer(Origin::signed(11), 20, 1),
-			"account liquidity restrictions prevent withdrawal",
+			DispatchError::Module {
+				index: 0,
+				error: 1,
+				message: Some("LiquidityRestrictions"),
+			}
 		);
 
 		// Give account 11 extra free balance
@@ -842,7 +861,11 @@ fn cannot_transfer_staked_balance_2() {
 		// Confirm account 21 can transfer at most 1000
 		assert_noop!(
 			Balances::transfer(Origin::signed(21), 20, 1001),
-			"account liquidity restrictions prevent withdrawal",
+			DispatchError::Module {
+				index: 0,
+				error: 1,
+				message: Some("LiquidityRestrictions"),
+			}
 		);
 		assert_ok!(Balances::transfer(Origin::signed(21), 20, 1000));
 	});
@@ -859,7 +882,14 @@ fn cannot_reserve_staked_balance() {
 		// Confirm account 11 (via controller 10) is totally staked
 		assert_eq!(Staking::stakers(&11).own, 1000);
 		// Confirm account 11 cannot transfer as a result
-		assert_noop!(Balances::reserve(&11, 1), "account liquidity restrictions prevent withdrawal");
+		assert_noop!(
+			Balances::reserve(&11, 1),
+			DispatchError::Module {
+				index: 0,
+				error: 1,
+				message: Some("LiquidityRestrictions"),
+			}
+		);
 
 		// Give account 11 extra free balance
 		let _ = Balances::make_free_balance_be(&11, 10000);
-- 
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