Cannot unmarshal hex string without 0x prefix

[MisaZ10]

Expected behavior

pragma solidity ^0.4.11;

contract Voting {
    mapping (bytes32 => uint8) public votesReceived;
    bytes32[] public candidateList;

    function Voting(bytes32[] candidateNames) {
        candidateList = candidateNames;
    }

    function totalVotesFor(bytes32 candidate) returns (uint8) {
        if (validCandidate(candidate) == false) throw;
        return votesReceived[candidate];
    }

    function voteForCandidate(bytes32 candidate) {
        if (validCandidate(candidate) == false) throw;
        votesReceived[candidate] += 1;
    }

    function validCandidate(bytes32 candidate) returns (bool) {
        for(uint i = 0; i < candidateList.length; i++) {
            if (candidateList[i] == candidate) {
                return true;
            }
        }
        return false;
    }
}

const Web3 = require('web3');
const solc = require('solc');
const fs = require('fs');

const provider = new Web3.providers.HttpProvider("http://localhost:8545")
const web3 = new Web3(provider);
const asciiToHex = Web3.utils.fromAscii;

const candidates = ['Rama', 'Nick', 'Jose'];

web3.eth.getAccounts()
.then((accounts) => {
  const code = fs.readFileSync('./voting.sol').toString();
  const compiledCode = solc.compile(code);
  const errors = [];
  const warnings = [];
  (compiledCode.errors || []).forEach((err) => {
    if (/\:\s*Warning\:/.test(err)) {
      warnings.push(err);
    } else {
      errors.push(err);
    }
  });

  if (errors.length) {
    throw new Error('solc.compile: ' + errors.join('\n'));
  }
  if (warnings.length) {
    console.warn('solc.compile: ' + warnings.join('\n'));
  }
  const byteCode = compiledCode.contracts[':Voting'].bytecode;
  const abiDefinition = JSON.parse(compiledCode.contracts[':Voting'].interface);

  const VotingContract = new web3.eth.Contract(abiDefinition,
    {data: byteCode, from: accounts[0], gas: 47}
  );

  let deployedContract = null;
  const votingHex = candidates.map(asciiToHex) // votingHex [ '0x52616d61', '0x4e69636b', '0x4a6f7365']
  VotingContract.deploy({
    data: byteCode,
    arguments: [votingHex]
  })
  .send(function (error, transactionHash) {
    if (error) new Error(error); // here return error
    console.log('transactionHash', transactionHash);
  })
  .catch((e) => {
    console.error(e)
    process.exit(1)
  })
});

This is a small example of a contract.
I want to deploy a smart contract and vote for candidate.

Actual behavior

I want to deploy a smart contract but in deploy function return error.

I am using Web3.js 1.0.0-beta.37 because with the version 1.0.0-beta.41 I have this issue
#2256

Steps to reproduce the behavior

1. Connect to private blockchain
2. Compile contract
3. Try to deploy contract with arguments (array to bytes32)

Error Logs

Error: Returned error: invalid argument 0: json: cannot unmarshal hex string without 0x prefix into Go struct field SendTxArgs.data of type hexutil.Bytes

Extra data

I created a private test blockchain with this genesis.json

{
  "config": {
    "chainId": 3,
    "homesteadBlock": 1,
    "eip150Block": 2,
    "eip150Hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "eip155Block": 3,
    "eip158Block": 3,
    "byzantiumBlock": 4,
    "clique": {
      "period": 5,
      "epoch": 30000
    }
  },
  "nonce": "0x0",
  "timestamp": "0x5a8efd25",
  "extraData": "0x00000000000000000000000000000000000000000000000000000000000000003590aca93338b0721966a8d0c96ebf2c4c87c5448cc5a1a0802db41db826c2fcb72423744338dcb00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  "gasLimit": "0xf42400",
  "difficulty": "0x1",
  "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "coinbase": "0x0000000000000000000000000000000000000000",
  "alloc": {
    "3590aca93338b0721966a8d0c96ebf2c4c87c544": {
      "balance": "0x200000000000000000000000000000000000000000000000000000000000000"
    },
    "8cc5a1a0802db41db826c2fcb72423744338dcb0": {
      "balance": "0x200000000000000000000000000000000000000000000000000000000000000"
    }
  },
  "number": "0x0",
  "gasUsed": "0x0",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000"
}

Versions

NPM 6.4.0
Node v8.11.1
Web3.js 1.0.0-beta.37
OS Ubuntu 18.04

[nivida]

Does this error still occur in the latest version (beta.44)? I've fixed issue #2256.

[MisaZ10]

With 1.0.0-beta.46 I have this result:

Error: invalid bytes32 value (arg="candidateNames", coderType="bytes32", value="0x52616d61", version=4.0.24)

[nivida]

Yes, this error happens because ethers.js added a strict validation for bytes* values.

Just change this line:

const votingHex = candidates.map(asciiToHex);

To:

const votingHex = candidates.map((value) => {
  return asciiToHex(value);
});

This is required because asciiToHex does have a default property for defining the bytes length the returned string should have. The default length is 32 bytes please check out the documentation for further details: web3.utils.asciiToHex.

Btw.: You could use the web3.utils.asciiToHex method directly instead of using the fromAscii alias.