fix: 🐛 fix conversion calculation problem (#529)

* fix: 🐛 fix conversion calculation problem * fix: 🐛 fix
bifrost-finance · Apr 1, 2022 · 4c34ddf · 4c34ddf
1 parent 919007b
commit 4c34ddf
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Showing 2 changed files with 26 additions and 9 deletions.
diff --git a/pallets/vstoken-conversion/src/lib.rs b/pallets/vstoken-conversion/src/lib.rs
@@ -41,6 +41,7 @@ use node_primitives::{CurrencyId, TokenSymbol};
 use orml_traits::MultiCurrency;
 pub use pallet::*;
 pub use primitives::{VstokenConversionExchangeFee, VstokenConversionExchangeRate};
+use sp_arithmetic::per_things::Percent;
 pub use weights::WeightInfo;
 
 #[allow(type_alias_bounds)]
@@ -265,11 +266,17 @@ pub mod pallet {
 				remaining_due_lease = 0i32
 			}
 			let exchange_rate = ExchangeRate::<T>::get(remaining_due_lease);
+			ensure!(
+				exchange_rate.vsksm_convert_to_vsbond != Percent::from_percent(0),
+				Error::<T>::CalculationOverflow
+			);
+
 			let exchange_fee = ExchangeFee::<T>::get();
 			let vsksm_balance = vsksm_amount
 				.checked_sub(&exchange_fee.vsksm_exchange_fee)
 				.ok_or(Error::<T>::CalculationOverflow)?;
-			let vsbond_balance = exchange_rate.vsksm_convert_to_vsbond * vsksm_balance;
+			let vsbond_balance =
+				exchange_rate.vsksm_convert_to_vsbond.saturating_reciprocal_mul(vsksm_balance);
 			ensure!(vsbond_balance >= minimum_vsbond, Error::<T>::NotEnoughBalance);
 
 			T::MultiCurrency::transfer(
@@ -409,11 +416,17 @@ pub mod pallet {
 				remaining_due_lease = 0i32
 			}
 			let exchange_rate = ExchangeRate::<T>::get(remaining_due_lease);
+			ensure!(
+				exchange_rate.vsdot_convert_to_vsbond != Percent::from_percent(0),
+				Error::<T>::CalculationOverflow
+			);
+
 			let exchange_fee = ExchangeFee::<T>::get();
 			let vsdot_balance = vsdot_amount
 				.checked_sub(&exchange_fee.vsdot_exchange_fee)
 				.ok_or(Error::<T>::CalculationOverflow)?;
-			let vsbond_balance = exchange_rate.vsdot_convert_to_vsbond * vsdot_balance;
+			let vsbond_balance =
+				exchange_rate.vsdot_convert_to_vsbond.saturating_reciprocal_mul(vsdot_balance);
 			ensure!(vsbond_balance >= minimum_vsbond, Error::<T>::NotEnoughBalance);
 
 			T::MultiCurrency::transfer(

diff --git a/pallets/vstoken-conversion/src/tests.rs b/pallets/vstoken-conversion/src/tests.rs
@@ -45,12 +45,16 @@ fn vsksm_convert_to_vsbond() {
 			vsdot_convert_to_vsbond: EXCHANGE_RATE_PERCENTAGE,
 		};
 		assert_ok!(VstokenConversion::set_kusama_lease(Origin::signed(ALICE), 1));
-		assert_ok!(VstokenConversion::set_exchange_rate(Origin::signed(ALICE), 8, EXCHANGE_RATE));
-		assert_eq!(VstokenConversion::exchange_rate(8), EXCHANGE_RATE);
 		assert_noop!(
 			VstokenConversion::vsksm_convert_to_vsbond(Some(BOB).into(), vsBond, 1000, 1),
 			Error::<Runtime>::NotEnoughBalance
 		);
+		assert_noop!(
+			VstokenConversion::vsksm_convert_to_vsbond(Some(BOB).into(), vsBond, 100, 1),
+			Error::<Runtime>::CalculationOverflow
+		);
+		assert_ok!(VstokenConversion::set_exchange_rate(Origin::signed(ALICE), 8, EXCHANGE_RATE));
+		assert_eq!(VstokenConversion::exchange_rate(8), EXCHANGE_RATE);
 		assert_noop!(
 			VstokenConversion::vsksm_convert_to_vsbond(Some(BOB).into(), vsBond, 100, 1),
 			orml_tokens::Error::<Runtime>::BalanceTooLow
@@ -60,11 +64,11 @@ fn vsksm_convert_to_vsbond() {
 			Error::<Runtime>::NotSupportTokenType
 		);
 		let vsbond_account: AccountId = <Runtime as Config>::VsbondAccount::get().into_account();
-		assert_ok!(<Tokens as MultiCurrency<AccountId>>::deposit(vsBond, &vsbond_account, 100));
+		assert_ok!(<Tokens as MultiCurrency<AccountId>>::deposit(vsBond, &vsbond_account, 10000));
 		assert_ok!(VstokenConversion::vsksm_convert_to_vsbond(Some(BOB).into(), vsBond, 100, 1));
 		assert_eq!(Tokens::free_balance(vsKSM, &BOB), 0);
-		assert_eq!(Tokens::free_balance(vsBond, &vsbond_account), 96);
-		assert_eq!(Tokens::free_balance(vsBond, &BOB), 104);
+		assert_eq!(Tokens::free_balance(vsBond, &vsbond_account), 8200);
+		assert_eq!(Tokens::free_balance(vsBond, &BOB), 1900);
 
 		assert_ok!(<Tokens as MultiCurrency<AccountId>>::deposit(vsKSM, &BOB, 1000));
 		pub const EXCHANGE_RATE_PERCENTAGE_0: Percent = Percent::from_percent(100);
@@ -78,8 +82,8 @@ fn vsksm_convert_to_vsbond() {
 		assert_ok!(VstokenConversion::set_exchange_rate(Origin::signed(ALICE), 0, EXCHANGE_RATE_0));
 		assert_ok!(VstokenConversion::vsksm_convert_to_vsbond(Some(BOB).into(), vsBond, 100, 1));
 		assert_eq!(Tokens::free_balance(vsKSM, &BOB), 900);
-		assert_eq!(Tokens::free_balance(vsBond, &vsbond_account), 6);
-		assert_eq!(Tokens::free_balance(vsBond, &BOB), 194);
+		assert_eq!(Tokens::free_balance(vsBond, &vsbond_account), 8110);
+		assert_eq!(Tokens::free_balance(vsBond, &BOB), 1990);
 	});
 }