Lesson 13 : VM Exception while processing transaction: reverted with reason string '31'

[BalamRamGas]

Hi everyone!!

When I run the aaveBorrow.js file I got the following error.

Error: VM Exception while processing transaction: reverted with reason string '31'

It seems that the function that is not working when called is borrowDai() because prior to that all the code was read properly but can't find the failure yet.

I consoled log the objects that the function need and everything seems to be correct.

By the way... I chose to work with aave V3.

aaveBorrow.js

const { getNamedAccounts, ethers } = require("hardhat")
const { getWeth, AMOUNT } = require("./getWeth")

async function main() {
    //The protocol treats everything as an ERC20
    await getWeth()
    const { deployer } = await getNamedAccounts()
    //abi , address
    //Aave - Pool Addresses Provider = 0x2f39d218133AFaB8F2B819B1066c7E434Ad94E9e
    //Lending pool
    const pool = await getPool(deployer)
    console.log(`Pool Address ${pool.address}`)

    const wethTokenAddress = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2"
    //aprove
    await approveERC20(wethTokenAddress, pool.address, AMOUNT, deployer)
    //deposit
    console.log(`Depositing ${AMOUNT} WETH...`)
    await pool.deposit(wethTokenAddress, AMOUNT, deployer, 0)
    console.log("Deposited!")
    //get user's data
    let { availableBorrowsBase, totalDebtBase } = await getBorrowUserData(pool, deployer)
    const daiEthPriceFeed = await getDaiPrice()
    const amountDaiToBorrow =
        availableBorrowsBase.toString() * 0.95 * (1 / daiEthPriceFeed.toString())
    console.log(`You can borrow ${amountDaiToBorrow * 1e6} DAI.`)
    const amountDaiToBorrowWei = ethers.utils.parseEther((amountDaiToBorrow * 1e6).toString())
    console.log(amountDaiToBorrowWei.toString())
    //Borrow Time!
    const daiTokenAddress = "0x6B175474E89094C44Da98b954EedeAC495271d0F"
    await borrowDai(daiTokenAddress, pool, amountDaiToBorrowWei, deployer)
    await getBorrowUserData(pool, deployer)
}

async function borrowDai(daiAddress, pool, amountDaiToBorrowWei, account) {
    const borrowTx = await pool.borrow(daiAddress, amountDaiToBorrowWei, 1, 0, account)
    await borrowTx.wait(1)
    console.log("You've borrowed!!!")
}

async function getDaiPrice() {
    //We don't need to use the deployer address since we are not going to sign any transaction, we are going to read only
    const daiEthPriceFeed = await ethers.getContractAt(
        "AggregatorV3Interface",
        "0x773616E4d11A78F511299002da57A0a94577F1f4"
    )
    const price = (await daiEthPriceFeed.latestRoundData())[1]
    console.log(`The DAI/ETH price is ${price.toString()}`)
    return price
}

async function getBorrowUserData(pool, account) {
    const { totalCollateralBase, totalDebtBase, availableBorrowsBase } =
        await pool.getUserAccountData(account)
    console.log(`You have ${totalCollateralBase} worth of ETH deposited.`)
    console.log(`You have ${totalDebtBase} of ETH borrowed.`)
    console.log(`You can borrow ${availableBorrowsBase} worth of ETH.`)
    return { availableBorrowsBase, totalDebtBase }
}

async function getPool(account) {
    const poolAddressesProvider = await ethers.getContractAt(
        "IPoolAddressesProvider",
        "0x2f39d218133AFaB8F2B819B1066c7E434Ad94E9e",
        account
    )
    const poolAddress = await poolAddressesProvider.getPool()
    const pool = await ethers.getContractAt("IPool", poolAddress, account)
    return pool
}

async function approveERC20(erc20Address, spenderAddress, amounToSpend, account) {
    const erc20Token = await ethers.getContractAt("IERC20", erc20Address, account)
    const transactionResponse = await erc20Token.approve(spenderAddress, amounToSpend)
    await transactionResponse.wait(1)
    console.log("Approved!")
}

main()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error)
        process.exit(1)
    })

It seems that someone else asked for the same question but didn't got a solution. I've been tinkering around for a while but not finding the answer out.

[BalamRamGas]

Not sure why... But this error only comes when the "borrow" function is called on the IPool.sol with the third parameter (uint256 InterestRateMode) settled as "1" (Stable). On the other hand... when I called the function with the number "2" (variable) the code didn't break.

How can we know there is a mistake on aave's side? or There was something wrong in my code?

In the meantime I will use the Variable Rate to continue the project.

[haoleo10]

same question. And I have a question for v3, do you know the unit of "totalCollateralBase" in "getUserAccountData" function ? USDC or USD dollar? Thank you so much

[Marcrus813]

Same problem and same "Work around" here, found anything yet?

[NIAZELOPER]

@haoleo10 getUserAccountData() method returns the values in markets base fees which means that it returns the value in the currency of the network on which it is called, for example on ethereum network the method returns value in ETH and also in hardhat local network the returned value are in ETH. But the problem I am facing is that this method is not returning that much collateral that I deposited. The returned value is much less.

[Nlferu]

Hello @BalamRamGas @haoleo10 @Marcrus813

Please be informed that Aave got updated and you should amend your codes accordingly to get those running.
Please see below:

async function borrowAsset(assetAddress, lendingPool, amountToBorrow, account) {
    /** @dev ILendingPool: function borrow(address asset, uint256 amount, uint256 interestRateMode, uint16 referralCode, address onBehalfOf) external; */
    /** Stable Interest Rate: 1 Variable Interest Rate: 2 (New Aave allows "2" variable now) */
    const borrowTx = await lendingPool.borrow(assetAddress, amountToBorrow, 2, 0, account)
    await borrowTx.wait(1)
}

Please also check following link

[0xdothis]

You should set the parameter for the 3rd argument which is interestRate to 2
1 is for stables and it has been disabled by aave.
works for me that way