swaps: fix max native check

src/hooks/useSwapInputHandlers.ts

@@ -3,12 +3,7 @@ import { useCallback } from 'react';
 import { useDispatch, useSelector } from 'react-redux';
 import { Alert } from '../components/alerts';
 import { isNativeAsset } from '@/handlers/assets';
-import {
-  greaterThan,
-  multiply,
-  subtract,
-  toFixedDecimals,
-} from '@/helpers/utilities';
+import { greaterThan, toFixedDecimals } from '@/helpers/utilities';
 import { useGas } from '@/hooks';
 import { AppState } from '@/redux/store';
 import {
@@ -20,7 +15,6 @@ import { ethereumUtils } from '@/utils';
 
 export default function useSwapInputHandlers() {
   const dispatch = useDispatch();
-  const type = useSelector((state: AppState) => state.swap.type);
 
   const { selectedGasFee, l1GasFeeOptimism } = useGas();
 
@@ -40,6 +34,7 @@ export default function useSwapInputHandlers() {
       isNativeAsset(inputCurrencyAddress, inputCurrencyNetwork) &&
       accountAsset
     ) {
+      // this subtracts gas from the balance of the asset
       newAmount = toFixedDecimals(
         ethereumUtils.getBalanceAmount(
           selectedGasFee,
@@ -48,14 +43,9 @@ export default function useSwapInputHandlers() {
         ),
         6
       );
-      const transactionFee = subtract(oldAmount, newAmount);
-      const newAmountMinusFee = toFixedDecimals(
-        subtract(newAmount, multiply(transactionFee, 1.5)),
-        6
-      );
 
-      if (greaterThan(newAmountMinusFee, 0)) {
-        dispatch(updateSwapInputAmount(newAmountMinusFee));
+      if (greaterThan(newAmount, 0)) {
+        dispatch(updateSwapInputAmount(newAmount));
       } else {
         Alert({
           message: lang.t(