add OnNewAccount and OnKilledAccount to orml-tokens

Author: apopiak

tokens/src/lib.rs

@@ -68,7 +68,7 @@ use orml_traits::{
 	arithmetic::{self, Signed},
 	currency::TransferAll,
 	BalanceStatus, GetByKey, LockIdentifier, MultiCurrency, MultiCurrencyExtended, MultiLockableCurrency,
-	MultiReservableCurrency, NamedMultiReservableCurrency, OnDust,
+	MultiReservableCurrency, NamedMultiReservableCurrency, OnDust, OnNewAccount, OnKilledAccount,
 };
 
 mod imbalances;
@@ -216,6 +216,12 @@ pub mod module {
 		/// Handler to burn or transfer account's dust
 		type OnDust: OnDust<Self::AccountId, Self::CurrencyId, Self::Balance>;
 
+		/// Handler for when an account was created
+		type OnNewAccount: OnNewAccount<Self::AccountId, Self::CurrencyId>;
+
+		/// Handler for when an account was created
+		type OnKilledAccount: OnKilledAccount<Self::AccountId, Self::CurrencyId>;
+
 		#[pallet::constant]
 		type MaxLocks: Get<u32>;
 
@@ -747,9 +753,11 @@ impl<T: Config> Pallet<T> {
 				// Ignore the result, because if it failed then there are remaining consumers,
 				// and the account storage in frame_system shouldn't be reaped.
 				let _ = frame_system::Pallet::<T>::dec_providers(who);
+				T::OnKilledAccount::on_killed_account(&who, currency_id);
 			} else if !existed && exists {
 				// if new, increase account provider
 				frame_system::Pallet::<T>::inc_providers(who);
+				T::OnNewAccount::on_new_account(&who, currency_id);
 			}
 
 			if let Some(endowed) = maybe_endowed {

tokens/src/mock.rs

@@ -220,6 +220,43 @@ parameter_type_with_key! {
 	};
 }
 
+thread_local! {
+	pub static CREATED: RefCell<Vec<(AccountId, CurrencyId)>> = RefCell::new(vec![]);
+	pub static KILLED: RefCell<Vec<(AccountId, CurrencyId)>> = RefCell::new(vec![]);
+}
+
+pub struct TrackCreatedAccounts;
+impl TrackCreatedAccounts {
+	pub fn accounts() -> Vec<(AccountId, CurrencyId)> {
+		CREATED.clone()
+	}
+
+	pub fn reset() {
+		*CREATED = RefCell::new(vec![]);
+	}
+}
+impl OnNewAccount<AccountId, CurrencyId> for TrackCreatedAccounts {
+	fn on_new_account(who: &AccountId, currency: CurrencyId) {
+		CREATED.push((who, CurrencyId));
+	}
+}
+
+pub struct TrackKilledAccounts;
+impl TrackKilledAccounts {
+	pub fn accounts() -> Vec<(AccountId, CurrencyId)> {
+		KILLED.clone()
+	}
+
+	pub fn reset() {
+		*KILLED = RefCell::new(vec![]);
+	}
+}
+impl OnNewAccount<AccountId, CurrencyId> for TrackKilledAccounts {
+	fn on_new_account(who: &AccountId, currency: CurrencyId) {
+		KILLED.push((who, CurrencyId));
+	}
+}
+
 parameter_types! {
 	pub DustReceiver: AccountId = PalletId(*b"orml/dst").into_account();
 }
@@ -232,6 +269,8 @@ impl Config for Runtime {
 	type WeightInfo = ();
 	type ExistentialDeposits = ExistentialDeposits;
 	type OnDust = TransferDust<Runtime, DustReceiver>;
+	type OnNewAccount = TrackCreatedAccounts;
+	type OnKilledAccount = TrackKilledAccounts;
 	type MaxLocks = ConstU32<2>;
 	type MaxReserves = ConstU32<2>;
 	type ReserveIdentifier = ReserveIdentifier;
@@ -296,6 +335,9 @@ impl ExtBuilder {
 			.unwrap();
 		}
 
+		TrackCreatedAccounts::reset();
+		TrackKilledAccounts::reset();
+
 		let mut ext = sp_io::TestExternalities::new(t);
 		ext.execute_with(|| System::set_block_number(1));
 		ext

tokens/src/tests.rs

@@ -139,6 +139,7 @@ fn transfer_all_allow_death_should_work() {
 			}));
 			assert!(!Accounts::<Runtime>::contains_key(ALICE, DOT));
 			assert_eq!(Tokens::free_balance(DOT, &ALICE), 0);
+			assert_eq!(TrackKilledAccounts::accounts(), vec![(ALICE, DOT)]);
 
 			assert_ok!(Tokens::set_lock(ID_1, DOT, &BOB, 50));
 			assert_eq!(Tokens::accounts(&BOB, DOT).frozen, 50);
@@ -513,6 +514,7 @@ fn set_free_balance_should_work() {
 
 		Tokens::set_free_balance(DOT, &ALICE, 2);
 		assert!(Accounts::<Runtime>::contains_key(ALICE, DOT));
+		assert_eq!(TrackCreatedAccounts::accounts(), vec![(ALICE, DOT)]);
 		assert_eq!(Tokens::free_balance(DOT, &ALICE), 2);
 		assert_eq!(Tokens::free_balance(DOT, &DustReceiver::get()), 1);
 

traits/src/currency.rs

@@ -643,6 +643,24 @@ impl<AccountId, CurrencyId, Balance> OnDust<AccountId, CurrencyId, Balance> for
 	fn on_dust(_: &AccountId, _: CurrencyId, _: Balance) {}
 }
 
+/// Handler for a newly created account
+pub trait OnNewAccount<AccountId, CurrencyId> {
+	fn on_new_account(who: &AccountId, currency_id: CurrencyId);
+}
+
+impl<AccountId, CurrencyId, Balance> OnDust<AccountId, CurrencyId> for () {
+	fn on_new_account(_: &AccountId, _: CurrencyId) {}
+}
+
+/// Handler for an account that was removed
+pub trait OnKilledAccount<AccountId, CurrencyId> {
+	fn on_killed_account(who: &AccountId, currency_id: CurrencyId);
+}
+
+impl<AccountId, CurrencyId, Balance> OnDust<AccountId, CurrencyId> for () {
+	fn on_killed_account(_: &AccountId, _: CurrencyId) {}
+}
+
 pub trait TransferAll<AccountId> {
 	fn transfer_all(source: &AccountId, dest: &AccountId) -> DispatchResult;
 }