Support Staking Payout to Any Account (#6832)

* Support staking payout to any account

* fix offences benchmarks

substrate/frame/offences/benchmarking/src/lib.rs

@@ -125,7 +125,7 @@ fn create_offender<T: Trait>(n: u32, nominators: u32) -> Result<Offender<T>, &'s
 			RawOrigin::Signed(nominator_stash.clone()).into(),
 			nominator_controller_lookup.clone(),
 			amount.clone(),
-			reward_destination,
+			reward_destination.clone(),
 		)?;
 
 		let selected_validators: Vec<LookupSourceOf<T>> = vec![controller_lookup.clone()];

substrate/frame/staking/src/lib.rs

@@ -425,16 +425,18 @@ pub enum StakerStatus<AccountId> {
 
 /// A destination account for payment.
 #[derive(PartialEq, Eq, Copy, Clone, Encode, Decode, RuntimeDebug)]
-pub enum RewardDestination {
+pub enum RewardDestination<AccountId> {
 	/// Pay into the stash account, increasing the amount at stake accordingly.
 	Staked,
 	/// Pay into the stash account, not increasing the amount at stake.
 	Stash,
 	/// Pay into the controller account.
 	Controller,
+	/// Pay into a specified account.
+	Account(AccountId),
 }
 
-impl Default for RewardDestination {
+impl<AccountId> Default for RewardDestination<AccountId> {
 	fn default() -> Self {
 		RewardDestination::Staked
 	}
@@ -1049,7 +1051,7 @@ decl_storage! {
 			=> Option<StakingLedger<T::AccountId, BalanceOf<T>>>;
 
 		/// Where the reward payment should be made. Keyed by stash.
-		pub Payee get(fn payee): map hasher(twox_64_concat) T::AccountId => RewardDestination;
+		pub Payee get(fn payee): map hasher(twox_64_concat) T::AccountId => RewardDestination<T::AccountId>;
 
 		/// The map from (wannabe) validator stash key to the preferences of that validator.
 		pub Validators get(fn validators):
@@ -1496,7 +1498,7 @@ decl_module! {
 		pub fn bond(origin,
 			controller: <T::Lookup as StaticLookup>::Source,
 			#[compact] value: BalanceOf<T>,
-			payee: RewardDestination,
+			payee: RewardDestination<T::AccountId>,
 		) {
 			let stash = ensure_signed(origin)?;
 
@@ -1830,7 +1832,7 @@ decl_module! {
 		///     - Write: Payee
 		/// # </weight>
 		#[weight = 11 * WEIGHT_PER_MICROS + T::DbWeight::get().reads_writes(1, 1)]
-		fn set_payee(origin, payee: RewardDestination) {
+		fn set_payee(origin, payee: RewardDestination<T::AccountId>) {
 			let controller = ensure_signed(origin)?;
 			let ledger = Self::ledger(&controller).ok_or(Error::<T>::NotController)?;
 			let stash = &ledger.stash;
@@ -2489,6 +2491,9 @@ impl<T: Trait> Module<T> {
 					Self::update_ledger(&controller, &l);
 					r
 				}),
+			RewardDestination::Account(dest_account) => {
+				Some(T::Currency::deposit_creating(&dest_account, amount))
+			}
 		}
 	}
 

substrate/frame/staking/src/tests.rs

@@ -4359,7 +4359,7 @@ fn test_payout_stakers() {
 	// We also test that `payout_extra_nominators` works.
 	ExtBuilder::default().has_stakers(false).build_and_execute(|| {
 		let balance = 1000;
-		// Create three validators:
+		// Create a validator:
 		bond_validator(11, 10, balance); // Default(64)
 
 		// Create nominators, targeting stash of validators
@@ -4597,15 +4597,12 @@ fn on_initialize_weight_is_correct() {
 	});
 }
 
-
 #[test]
 fn payout_creates_controller() {
-	// Here we will test validator can set `max_nominators_payout` and it works.
-	// We also test that `payout_extra_nominators` works.
 	ExtBuilder::default().has_stakers(false).build_and_execute(|| {
 		let balance = 1000;
-		// Create three validators:
-		bond_validator(11, 10, balance); // Default(64)
+		// Create a validator:
+		bond_validator(11, 10, balance);
 
 		// Create a stash/controller pair
 		bond_nominator(1234, 1337, 100, vec![11]);
@@ -4626,3 +4623,32 @@ fn payout_creates_controller() {
 		assert!(Balances::free_balance(1337) > 0);
 	})
 }
+
+#[test]
+fn payout_to_any_account_works() {
+	ExtBuilder::default().has_stakers(false).build_and_execute(|| {
+		let balance = 1000;
+		// Create a validator:
+		bond_validator(11, 10, balance); // Default(64)
+
+		// Create a stash/controller pair
+		bond_nominator(1234, 1337, 100, vec![11]);
+
+		// Update payout location
+		assert_ok!(Staking::set_payee(Origin::signed(1337), RewardDestination::Account(42)));
+
+		// Reward Destination account doesn't exist
+		assert_eq!(Balances::free_balance(42), 0);
+
+		mock::start_era(1);
+		Staking::reward_by_ids(vec![(11, 1)]);
+		// Compute total payout now for whole duration as other parameter won't change
+		let total_payout_0 = current_total_payout_for_duration(3 * 1000);
+		assert!(total_payout_0 > 100); // Test is meaningful if reward something
+		mock::start_era(2);
+		assert_ok!(Staking::payout_stakers(Origin::signed(1337), 11, 1));
+
+		// Payment is successful
+		assert!(Balances::free_balance(42) > 0);
+	})
+}