better handling of rounding issues in borrow and withdraw

components/WithdrawModal.tsx

@@ -7,7 +7,8 @@ import useMangoStore from '../stores/useMangoStore'
 import useMarketList from '../hooks/useMarketList'
 import {
   getSymbolForTokenMintAddress,
-  formatBalanceDisplay,
+  displayDepositsForMarginAccount,
+  floorToDecimal,
 } from '../utils/index'
 import useConnection from '../hooks/useConnection'
 import { borrowAndWithdraw, withdraw } from '../utils/mango'
@@ -59,7 +60,11 @@ const WithdrawModal = ({ isOpen, onClose }) => {
   const getMaxForSelectedAccount = () => {
     const marginAccount = useMangoStore.getState().selectedMarginAccount.current
     const mangoGroup = useMangoStore.getState().selectedMangoGroup.current
-    return marginAccount.getUiDeposit(mangoGroup, tokenIndex)
+    return displayDepositsForMarginAccount(
+      marginAccount,
+      mangoGroup,
+      tokenIndex
+    )
   }
 
   const setMaxForSelectedAccount = () => {
@@ -72,26 +77,27 @@ const WithdrawModal = ({ isOpen, onClose }) => {
   }
 
   const setMaxBorrowForSelectedAccount = async () => {
+    // get index prices
     const prices = await selectedMangoGroup.getPrices(connection)
-    const assetsValBeforeTokenBal = selectedMarginAccount.getAssetsVal(
-      selectedMangoGroup,
-      prices
-    )
+    // get value of margin account assets minus the selected token
     const assetsVal =
-      assetsValBeforeTokenBal - getMaxForSelectedAccount() * prices[tokenIndex]
-
+      selectedMarginAccount.getAssetsVal(selectedMangoGroup, prices) -
+      getMaxForSelectedAccount() * prices[tokenIndex]
     const currentLiabs = selectedMarginAccount.getLiabsVal(
       selectedMangoGroup,
       prices
     )
+    // multiply by 0.99 and subtract 0.01 to account for rounding issues
     const liabsAvail = (assetsVal / 1.2 - currentLiabs) * 0.99 - 0.01
-
     const amountToWithdraw =
       liabsAvail / prices[tokenIndex] + getMaxForSelectedAccount()
-    const decimals = mintDecimals[getTokenIndex(mintAddress)]
+
     if (amountToWithdraw > 0) {
       setInputAmount(
-        formatBalanceDisplay(amountToWithdraw, decimals).toString()
+        floorToDecimal(
+          amountToWithdraw,
+          mintDecimals[getTokenIndex(mintAddress)]
+        ).toString()
       )
     } else {
       setInputAmount('0')

hooks/useBalances.tsx

@@ -3,6 +3,11 @@ import { Balances } from '../@types/types'
 import { nativeToUi } from '@blockworks-foundation/mango-client'
 import useMarketList from './useMarketList'
 import useMangoStore from '../stores/useMangoStore'
+import {
+  displayBorrowsForMarginAccount,
+  displayDepositsForMarginAccount,
+  floorToDecimal,
+} from '../utils'
 
 export function useBalances(): Balances[] {
   const { baseCurrency, quoteCurrency, market } = useMarket()
@@ -47,10 +52,14 @@ export function useBalances(): Balances[] {
   const tokenIndex = marketIndex
 
   const net = (borrows, currencyIndex) => {
-    return (
+    const amount =
       marginAccount.getNativeDeposit(mangoGroup, currencyIndex) +
       borrows -
       marginAccount.getNativeBorrow(mangoGroup, currencyIndex)
+
+    return floorToDecimal(
+      nativeToUi(amount, mangoGroup.mintDecimals[currencyIndex]),
+      mangoGroup.mintDecimals[currencyIndex]
     )
   }
 
@@ -59,31 +68,38 @@ export function useBalances(): Balances[] {
       market,
       key: `${baseCurrency}${quoteCurrency}${baseCurrency}`,
       coin: baseCurrency,
-      marginDeposits:
-        mangoGroup && marginAccount
-          ? marginAccount.getUiDeposit(mangoGroup, baseCurrencyIndex)
-          : null,
-      borrows: marginAccount.getUiBorrow(mangoGroup, baseCurrencyIndex),
+      marginDeposits: displayDepositsForMarginAccount(
+        marginAccount,
+        mangoGroup,
+        baseCurrencyIndex
+      ),
+      borrows: displayBorrowsForMarginAccount(
+        marginAccount,
+        mangoGroup,
+        baseCurrencyIndex
+      ),
       orders: nativeToUi(nativeBaseLocked, mangoGroup.mintDecimals[tokenIndex]),
       openOrders,
       unsettled: nativeToUi(
         nativeBaseUnsettled,
         mangoGroup.mintDecimals[tokenIndex]
       ),
-      net: nativeToUi(
-        net(nativeBaseLocked, tokenIndex),
-        mangoGroup.mintDecimals[tokenIndex]
-      ),
+      net: net(nativeBaseLocked, tokenIndex),
     },
     {
       market,
       key: `${quoteCurrency}${baseCurrency}${quoteCurrency}`,
       coin: quoteCurrency,
-      marginDeposits:
-        mangoGroup && marginAccount
-          ? marginAccount.getUiDeposit(mangoGroup, quoteCurrencyIndex)
-          : null,
-      borrows: marginAccount.getUiBorrow(mangoGroup, quoteCurrencyIndex),
+      marginDeposits: displayDepositsForMarginAccount(
+        marginAccount,
+        mangoGroup,
+        quoteCurrencyIndex
+      ),
+      borrows: displayBorrowsForMarginAccount(
+        marginAccount,
+        mangoGroup,
+        quoteCurrencyIndex
+      ),
       openOrders,
       orders: nativeToUi(
         nativeQuoteLocked,
@@ -93,10 +109,7 @@ export function useBalances(): Balances[] {
         nativeQuoteUnsettled,
         mangoGroup.mintDecimals[quoteCurrencyIndex]
       ),
-      net: nativeToUi(
-        net(nativeQuoteLocked, quoteCurrencyIndex),
-        mangoGroup.mintDecimals[quoteCurrencyIndex]
-      ),
+      net: net(nativeQuoteLocked, quoteCurrencyIndex),
     },
   ]
 }

utils/index.ts

@@ -24,6 +24,26 @@ export const percentFormat = new Intl.NumberFormat(undefined, {
   maximumFractionDigits: 2,
 })
 
+export function displayDepositsForMarginAccount(
+  marginAccount,
+  mangoGroup,
+  tokenIndex
+) {
+  const deposit = marginAccount.getUiDeposit(mangoGroup, tokenIndex)
+  const decimals = mangoGroup.mintDecimals[tokenIndex]
+  return floorToDecimal(deposit, decimals)
+}
+
+export function displayBorrowsForMarginAccount(
+  marginAccount,
+  mangoGroup,
+  tokenIndex
+) {
+  const borrow = marginAccount.getUiBorrow(mangoGroup, tokenIndex)
+  const decimals = mangoGroup.mintDecimals[tokenIndex]
+  return ceilToDecimal(borrow, decimals)
+}
+
 export function floorToDecimal(
   value: number,
   decimals: number | undefined | null
@@ -33,6 +53,15 @@ export function floorToDecimal(
     : Math.floor(value)
 }
 
+export function ceilToDecimal(
+  value: number,
+  decimals: number | undefined | null
+) {
+  return decimals
+    ? Math.ceil(value * 10 ** decimals) / 10 ** decimals
+    : Math.ceil(value)
+}
+
 export function roundToDecimal(
   value: number,
   decimals: number | undefined | null

utils/mango.tsx

@@ -389,9 +389,10 @@ export async function borrowAndWithdraw(
   const tokenBalance = marginAccount.getUiDeposit(mangoGroup, tokenIndex)
   const borrowQuantity = withdrawQuantity - tokenBalance
 
-  const nativeBorrowQuantity = uiToNative(
-    borrowQuantity,
-    mangoGroup.mintDecimals[tokenIndex]
+  const nativeBorrowQuantity = new BN(
+    Math.ceil(
+      borrowQuantity * Math.pow(10, mangoGroup.mintDecimals[tokenIndex])
+    )
   )
 
   const borrowInstruction = makeBorrowInstruction(