fix overflow in grant instruction (#179)

Author: 0xShuk

VoteStakeRegistry/actions/getGrantInstruction.ts

@@ -13,6 +13,7 @@ import {
   TOKEN_PROGRAM_ID,
 } from '@solana/spl-token'
 import { VsrClient } from 'VoteStakeRegistry/sdk/client'
+import { fmtDecimalToBN } from '@utils/formatting'
 
 export const getGrantInstruction = async ({
   fromPk,
@@ -21,6 +22,7 @@ export const getGrantInstruction = async ({
   grantMintPk,
   communityMintPk,
   amount,
+  decimals,
   lockupPeriod,
   startTime,
   lockupKind,
@@ -36,6 +38,7 @@ export const getGrantInstruction = async ({
   realmPk: PublicKey
   tokenAuthority: PublicKey
   amount: number
+  decimals: number
   //days or months in case of monthly vesting lockup type
   lockupPeriod: number
   lockupKind: LockupType
@@ -73,7 +76,7 @@ export const getGrantInstruction = async ({
       new BN(startTime),
       lockupPeriod,
       allowClawback,
-      new BN(amount),
+      fmtDecimalToBN(amount, decimals)
     )
     .accounts({
       registrar,

VoteStakeRegistry/components/instructions/Grant.tsx

@@ -4,7 +4,6 @@ import Input from '@components/inputs/Input'
 import useRealm from '@hooks/useRealm'
 import {
   getMintMinAmountAsDecimal,
-  parseMintNaturalAmountFromDecimal,
 } from '@tools/sdk/units'
 import { PublicKey, TransactionInstruction } from '@solana/web3.js'
 import { precision } from '@utils/formatting'
@@ -151,10 +150,6 @@ const Grant = ({
       const sourceAccount =
         form.governedTokenAccount.extensions.token?.account.address
       const destinationAccount = new PublicKey(form.destinationAccount)
-      const mintAmount = parseMintNaturalAmountFromDecimal(
-        form.amount!,
-        form.governedTokenAccount.extensions.mint.account.decimals,
-      )
 
       const destinationTokenOwnerRecordPk = await getTokenOwnerRecordAddress(
         realm.owner,
@@ -194,7 +189,8 @@ const Grant = ({
         tokenAuthority:
           form.governedTokenAccount.extensions.token.account.owner,
         grantMintPk: form.governedTokenAccount.extensions.mint.publicKey,
-        amount: mintAmount,
+        amount: form.amount!,
+        decimals: form.governedTokenAccount.extensions.mint.account.decimals,
         lockupPeriod: form.periods,
         startTime: form.startDateUnixSeconds,
         lockupKind: form.lockupKind.value,

utils/formatting.tsx

@@ -82,3 +82,18 @@ export const fmtTimeToString = ({
 }
 
 export { abbreviateAddress }
+
+export const fmtDecimalToBN = (
+  num: number,
+  decimals: number,
+) => {
+  const value = num.toString()
+  const decimalIndex = value.indexOf('.')
+  const decimalPlaces = decimalIndex !== -1 ? value.length - decimalIndex - 1 : 0
+  let wholeNumber = value.replace('.', '')
+  wholeNumber = decimals > decimalPlaces 
+    ? wholeNumber + '0'.repeat(decimals - decimalPlaces) 
+    : wholeNumber.slice(0, decimalIndex) + wholeNumber.slice(decimalIndex + 1, decimals + decimalIndex + 1)
+  
+  return new BN(wholeNumber)
+}