error Dai/insufficient-allowance even when sufficient amount has been approved

Question

I am testing smart contract interaction with Gains.trade on hardhat mainnet fork. However i always got this error Error: VM Exception while processing transaction: reverted with reason string 'Dai/insufficient-allowance'. I have approve the contract but still got the error.

async function main() {

await helpers.impersonateAccount(mimic);
const impersonate = await ethers.getSigner(mimic);


console.log(
    "Vitalik account before transaction",
    ethers.formatEther(await ethers.provider.getBalance(impersonate))
  );

const gns = new ethers.Contract(gainsAddress, gainsTrading, provider)
const dai = new ethers.Contract(DaiAddress, DaiABI, provider)

const price = await getGainsPrice();

// const convPrice = parseInt(ethers.parseUnits(price.toString(), 8));


const convPrice = price / (10 ** 8);
const tp = convPrice + (0.01 * convPrice * (15 / 5));
console.log(`tp: ${tp}`)
const tpCov = tp * (10 ** 10)

const contractPrice =  convPrice * (10 ** 10);
// const floor = Math.floor(contractPrice);


console.log(`contract price: ${contractPrice}`);
console.log(`tp conversion: ${tpCov}`)


const tradeTuple = {
    'trader': mimic,
    'pairIndex': 0,
    'index': 0,  //tradeIndex
    'initialPosToken': 0,
    'positionSizeDai': ethers.parseUnits('2000', 18).toString(),  // collateral in 1e18
    'openPrice': BigInt(contractPrice),
    'buy': true,
    'leverage': 5,  //leverage adjustable by slider on frontend
    'tp': BigInt(tpCov),
    'sl': 0
}

console.log(contractPrice)


const daiTransaction = await dai.connect(impersonate).approve(
    gainsAddress,
    ethers.parseUnits('2000', 18).toString()
)
const daiReceipt = await daiTransaction.wait()
console.log(daiReceipt.blockNumber)

const trade = await gns.connect(impersonate).openTrade(
    tradeTuple, 0, 0, '12492725505', '0x0000000000000000000000000000000000000000'
)
const tradeReceipt = await trade.wait()
console.log(tradeReceipt.blockNumber)

}

Answer 1

Try waiting for the first apporve transaction to get executed on the blockchain as it may be in progress when you are calling the trade function .