Add arithmetic dispatch errors. (#8726)

* Add arithmetic dispatch errors.

* Replace custom overflow errors.

* Replace custom underflow and division by zero errors.

* Replace overflow/underflow in token error.

* Add token and arithmetic errors in dispatch error equality test.

* Trigger CI.

substrate/frame/assets/README.md

@@ -71,6 +71,7 @@ Import the Assets module and types and derive your runtime's configuration trait
 use pallet_assets as assets;
 use frame_support::{decl_module, dispatch, ensure};
 use frame_system::ensure_signed;
+use sp_runtime::ArithmeticError;
 
 pub trait Config: assets::Config { }
 
@@ -84,7 +85,7 @@ decl_module! {
 			const COUNT_AIRDROP_RECIPIENTS: u64 = 2;
 			const TOKENS_FIXED_SUPPLY: u64 = 100;
 
-			ensure!(!COUNT_AIRDROP_RECIPIENTS.is_zero(), "Divide by zero error.");
+			ensure!(!COUNT_AIRDROP_RECIPIENTS.is_zero(), ArithmeticError::DivisionByZero);
 
 			let asset_id = Self::next_asset_id();
 

substrate/frame/assets/src/functions.rs

@@ -47,7 +47,7 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		who: &T::AccountId,
 		d: &mut AssetDetails<T::Balance, T::AccountId, DepositBalanceOf<T, I>>,
 	) -> Result<bool, DispatchError> {
-		let accounts = d.accounts.checked_add(1).ok_or(Error::<T, I>::Overflow)?;
+		let accounts = d.accounts.checked_add(1).ok_or(ArithmeticError::Overflow)?;
 		let is_sufficient = if d.is_sufficient {
 			frame_system::Pallet::<T>::inc_sufficients(who);
 			d.sufficients += 1;
@@ -162,7 +162,7 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		id: T::AssetId,
 		who: &T::AccountId,
 		keep_alive: bool,
-	) -> Result<T::Balance, Error<T, I>> {
+	) -> Result<T::Balance, DispatchError> {
 		let details = Asset::<T, I>::get(id).ok_or_else(|| Error::<T, I>::Unknown)?;
 		ensure!(!details.is_frozen, Error::<T, I>::Frozen);
 
@@ -173,7 +173,7 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 			// Frozen balance: account CANNOT be deleted
 			let required = frozen
 				.checked_add(&details.min_balance)
-				.ok_or(Error::<T, I>::Overflow)?;
+				.ok_or(ArithmeticError::Overflow)?;
 			account.balance.saturating_sub(required)
 		} else {
 			let is_provider = false;

substrate/frame/assets/src/lib.rs

@@ -140,7 +140,7 @@ pub use types::*;
 
 use sp_std::{prelude::*, borrow::Borrow};
 use sp_runtime::{
-	RuntimeDebug, TokenError, traits::{
+	RuntimeDebug, TokenError, ArithmeticError, traits::{
 		AtLeast32BitUnsigned, Zero, StaticLookup, Saturating, CheckedSub, CheckedAdd, Bounded,
 		StoredMapError,
 	}
@@ -326,8 +326,6 @@ pub mod pallet {
 		BadWitness,
 		/// Minimum balance should be non-zero.
 		MinBalanceZero,
-		/// A mint operation lead to an overflow.
-		Overflow,
 		/// No provider reference exists to allow a non-zero balance of a non-self-sufficient asset.
 		NoProvider,
 		/// Invalid metadata given.