fix: apply swap fee to token in/out amount for each hop in a multi ho…

…p scenario (#466) * fix: fix swap fee issue * test: fix unit tests
elys-network · Apr 23, 2024 · ffb0c9b · ffb0c9b
1 parent b34873e
commit ffb0c9b
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Showing 6 changed files with 10 additions and 8 deletions.
diff --git a/x/amm/keeper/keeper_swap_exact_amount_in.go b/x/amm/keeper/keeper_swap_exact_amount_in.go
@@ -59,7 +59,7 @@ func (k Keeper) SwapExactAmountIn(
 
 	// Settles balances between the tx sender and the pool to match the swap that was executed earlier.
 	// Also emits a swap event and updates related liquidity metrics.
-	_, err = k.UpdatePoolForSwap(ctx, pool, sender, recipient, tokenIn, tokenOutCoin, sdk.ZeroDec(), swapFee, weightBalanceBonus)
+	swapOutFee, err := k.UpdatePoolForSwap(ctx, pool, sender, recipient, tokenIn, tokenOutCoin, sdk.ZeroDec(), swapFee, weightBalanceBonus)
 	if err != nil {
 		return math.Int{}, err
 	}
@@ -68,5 +68,5 @@ func (k Keeper) SwapExactAmountIn(
 	k.TrackSlippage(ctx, pool.PoolId, sdk.NewCoin(tokenOutCoin.Denom, slippageAmount.RoundInt()))
 
 	// Subtract swap out fee from the token out amount.
-	return tokenOutAmount, nil
+	return tokenOutAmount.Sub(swapOutFee), nil
 }
diff --git a/x/amm/keeper/keeper_swap_exact_amount_in_test.go b/x/amm/keeper/keeper_swap_exact_amount_in_test.go
@@ -76,7 +76,7 @@ func (suite *KeeperTestSuite) TestSwapExactAmountIn() {
 			swapFeeOut:          sdk.ZeroDec(),
 			tokenIn:             sdk.NewInt64Coin("uusda", 10000),
 			tokenOutMin:         sdk.ZeroInt(),
-			tokenOut:            sdk.NewInt64Coin(ptypes.BaseCurrency, 9802),
+			tokenOut:            sdk.NewInt64Coin(ptypes.BaseCurrency, 9704),
 			weightBalanceBonus:  sdk.ZeroDec(),
 			isOraclePool:        false,
 			useNewRecipient:     false,

diff --git a/x/amm/keeper/keeper_swap_exact_amount_out.go b/x/amm/keeper/keeper_swap_exact_amount_out.go
@@ -55,12 +55,14 @@ func (k Keeper) SwapExactAmountOut(
 		return math.Int{}, errorsmod.Wrapf(types.ErrLimitMaxAmount, "swap requires %s, which is greater than the amount %s", tokenIn, tokenInMaxAmount)
 	}
 
-	_, err = k.UpdatePoolForSwap(ctx, pool, sender, recipient, tokenIn, tokenOut, swapFee, sdk.ZeroDec(), weightBalanceBonus)
+	swapOutFee, err := k.UpdatePoolForSwap(ctx, pool, sender, recipient, tokenIn, tokenOut, swapFee, sdk.ZeroDec(), weightBalanceBonus)
 	if err != nil {
 		return math.Int{}, err
 	}
 
 	// track slippage
 	k.TrackSlippage(ctx, pool.PoolId, sdk.NewCoin(tokenIn.Denom, slippageAmount.RoundInt()))
-	return tokenInAmount, nil
+
+	// Subtract swap out fee from the token out amount.
+	return tokenInAmount.Sub(swapOutFee), nil
 }
diff --git a/x/amm/keeper/msg_server_swap_by_denom_test.go b/x/amm/keeper/msg_server_swap_by_denom_test.go
@@ -28,7 +28,7 @@ func (suite *KeeperTestSuite) TestMsgServerSwapByDenom() {
 			swapFee:           sdk.NewDecWithPrec(1, 2), // 1%
 			tokenIn:           sdk.NewInt64Coin(ptypes.Elys, 10000),
 			tokenOutMin:       sdk.ZeroInt(),
-			tokenOut:          sdk.NewInt64Coin(ptypes.BaseCurrency, 9802),
+			tokenOut:          sdk.NewInt64Coin(ptypes.BaseCurrency, 9704),
 			expSenderBalance:  sdk.Coins{sdk.NewInt64Coin(ptypes.Elys, 990000), sdk.NewInt64Coin(ptypes.BaseCurrency, 1009704)},
 			expPass:           true,
 		},

diff --git a/x/amm/keeper/msg_server_swap_exact_amount_in_test.go b/x/amm/keeper/msg_server_swap_exact_amount_in_test.go
@@ -30,7 +30,7 @@ func (suite *KeeperTestSuite) TestMsgServerSwapExactAmountIn() {
 			swapFee:           sdk.NewDecWithPrec(1, 2), // 1%
 			tokenIn:           sdk.NewInt64Coin(ptypes.Elys, 10000),
 			tokenOutMin:       sdk.ZeroInt(),
-			tokenOut:          sdk.NewInt64Coin(ptypes.BaseCurrency, 9802),
+			tokenOut:          sdk.NewInt64Coin(ptypes.BaseCurrency, 9704),
 			swapRoute: []types.SwapAmountInRoute{
 				{
 					PoolId:        1,

diff --git a/x/amm/keeper/route_exact_amount_in_test.go b/x/amm/keeper/route_exact_amount_in_test.go
@@ -67,7 +67,7 @@ func (suite *KeeperTestSuite) TestRouteExactAmountIn() {
 			swapFeeOut:          sdk.ZeroDec(),
 			tokenIn:             sdk.NewInt64Coin(ptypes.Elys, 10000),
 			tokenOutMin:         sdk.ZeroInt(),
-			tokenOut:            sdk.NewInt64Coin(ptypes.BaseCurrency, 9802),
+			tokenOut:            sdk.NewInt64Coin(ptypes.BaseCurrency, 9704),
 			weightBalanceBonus:  sdk.ZeroDec(),
 			expSenderBalance:    sdk.Coins{sdk.NewInt64Coin(ptypes.Elys, 990000), sdk.NewInt64Coin(ptypes.BaseCurrency, 1009704)},
 			expPoolBalance:      sdk.Coins{sdk.NewInt64Coin(ptypes.Elys, 1010000), sdk.NewInt64Coin(ptypes.BaseCurrency, 990198)},