Add transfer_all to Currencies

currencies/src/default_weight.rs

@@ -12,6 +12,11 @@ impl crate::WeightInfo for () {
 			.saturating_add(DbWeight::get().reads(5 as Weight))
 			.saturating_add(DbWeight::get().writes(2 as Weight))
 	}
+	fn transfer_all_non_native_currency() -> Weight {
+		(172_011_000 as Weight)
+			.saturating_add(DbWeight::get().reads(5 as Weight))
+			.saturating_add(DbWeight::get().writes(2 as Weight))
+	}
 	fn transfer_native_currency() -> Weight {
 		(43_023_000 as Weight)
 	}

currencies/src/lib.rs

@@ -77,6 +77,7 @@ pub mod module {
 
 	pub trait WeightInfo {
 		fn transfer_non_native_currency() -> Weight;
+		fn transfer_all_non_native_currency() -> Weight;
 		fn transfer_native_currency() -> Weight;
 		fn update_balance_non_native_currency() -> Weight;
 		fn update_balance_native_currency_creating() -> Weight;
@@ -156,6 +157,24 @@ pub mod module {
 			Ok(().into())
 		}
 
+		/// Transfer all remaining balance to the given account under `currency_id`.
+		///
+		/// The dispatch origin for this call must be `Signed` by the
+		/// transactor.
+		#[pallet::weight(T::WeightInfo::transfer_all_non_native_currency())]
+		pub fn transfer_all(
+			origin: OriginFor<T>,
+			dest: <T::Lookup as StaticLookup>::Source,
+			currency_id: CurrencyIdOf<T>,
+		) -> DispatchResultWithPostInfo {
+			let from = ensure_signed(origin)?;
+			let to = T::Lookup::lookup(dest)?;
+			let balance = <Self as MultiCurrency<T::AccountId>>::free_balance(currency_id, &from);
+			<Self as MultiCurrency<T::AccountId>>::transfer(currency_id, &from, &to, balance)?;
+
+			Ok(().into())
+		}
+
 		/// Transfer some native currency to another account.
 		///
 		/// The dispatch origin for this call must be `Signed` by the

currencies/src/tests.rs

@@ -98,6 +98,18 @@ fn multi_currency_should_work() {
 		});
 }
 
+#[test]
+fn transfer_all_should_work() {
+	ExtBuilder::default()
+		.one_hundred_for_alice_n_bob()
+		.build()
+		.execute_with(|| {
+			assert_ok!(Currencies::transfer_all(Some(ALICE).into(), BOB, X_TOKEN_ID));
+			assert_eq!(Currencies::free_balance(X_TOKEN_ID, &ALICE), 0);
+			assert_eq!(Currencies::free_balance(X_TOKEN_ID, &BOB), 200);
+		});
+}
+
 #[test]
 fn multi_currency_extended_should_work() {
 	ExtBuilder::default()