truffle-troubleshoot/src/revert-reason.js

A Truffle plugin to troubleshoot your smart contract problems

const abi = require('ethereumjs-abi')
const chalk = require('chalk')
const util = require('ethereumjs-util')

const { getRawTransactionReceipt } = require('./raw-requests')

function isValidTransactionHash (transactionHash) {
  return /^0x([A-Fa-f0-9]{64})$/.test(transactionHash)
}

async function checkTransactionStatus (transactionReceipt) {
  if (transactionReceipt.result === null) {
    throw new Error('Transaction does not exist in this network')
  }

  if (transactionReceipt.result.status !== '0x0') {
    throw new Error('The transaction did not revert, it finished successfully.')
  }
}

async function getRevertReason (web3, transactionReceipt) {
  // the raw revert reason consists of the function selector, and the encoded string with the message
  const encodedRevertReasonWithFunctionSelector = await getRawRevertReason(web3, transactionReceipt)

  const encodedRevertReason = util.toBuffer(encodedRevertReasonWithFunctionSelector).slice(4)

  // the decoding function returns an array because it can be used to decode several values at once
  const revertReason = abi.rawDecode(['string'], encodedRevertReason)

  if (revertReason.length !== 1) {
    throw new Error('Could not decode the received result')
  }

  // in this case there is only one decoded value, which is the revert reason
  return revertReason[0].length > 0 ? chalk.green.bold(revertReason[0]) : chalk.yellow.bold('Could not retrieve revert reason in this network')
}

async function getRawRevertReason (web3, transactionReceipt) {
  // some clients, like Besu, return the revert reason directly in the receipt
  if ('revertReason' in transactionReceipt.result) {
    return transactionReceipt.result.revertReason
  }

  // for all other we need to replay the transaction to get it
  return getRawRevertReasonByReplayingTransaction(web3, transactionReceipt)
}

async function getRawRevertReasonByReplayingTransaction (web3, transactionReceipt) {
  const transaction = await web3.eth.getTransaction(transactionReceipt.result.transactionHash)

  const transactionObject = {
    from: transaction.from,
    to: transaction.to,
    value: transaction.value,
    gas: transaction.gas,
    gasPrice: transaction.gasPrice,
    data: transaction.input
  }

  return web3.eth.call(transactionObject, transaction.blockNumber)
}

async function revertReason (web3, config, transactionHash) {
  if (!isValidTransactionHash(transactionHash)) {
    throw new Error(`TransactionHash ${transactionHash} is not valid`)
  }

  const network = config.networks[config.network]

  if (!Object.keys(network).includes('host')) {
    throw new Error(`Network ${config.network} does not have a 'host' value`)
  }

  const transactionReceipt = await getRawTransactionReceipt(
    network.host,
    transactionHash
  )

  await checkTransactionStatus(transactionReceipt)

  return getRevertReason(web3, transactionReceipt)
}

module.exports = revertReason