Create and sends a raw ERC-20 token transaction with web3 v1.0 and Infura

sendRawTokenTransaction.js

const Web3 = require('web3');
const Tx = require('ethereumjs-tx');
const BigNumber = require('bignumber.js');
const abi = require('ethereumjs-abi');


// connect to Infura node
const web3 = new Web3(new Web3.providers.HttpProvider('https://ropsten.infura.io/v2/INFURA_PROJECT_ID'));
// the address that will send the test transaction
const addressFrom = 'SENDER_ADDRESS';
const privKey = 'SENDER_PRIVATE_KEY';
// the destination address
const addressTo = 'RECEIVER_ADDRESS';
// token details
const tokenAddress = 'TOKEN_CONTRACT_ADDRESS';
const amount = 0.5;
const tokenDecimal = 18; // default value

/** Create token transfer value as (10 ** token_decimal) * user_supplied_value
 * @dev BigNumber instead of BN to handle decimal user_supplied_value
 * @note web3.utils.toBigNumber is no more supported in web3@1.0.x
 */
const base = new BigNumber(10);
const valueToTransfer = base.pow(tokenDecimal)
  .times(amount);
/* Create token transfer ABI encoded data
 * `transfer()` method signature at https://eips.ethereum.org/EIPS/eip-20
 * ABI encoding ruleset at https://solidity.readthedocs.io/en/develop/abi-spec.html
 * Convert BigNumber to BN instance as ethereumjs-abi doesn't support BigNumber
 */
const rawData = abi.methodID('transfer', ['address', 'uint256']).toString('hex') +
  abi.rawEncode(['address', 'uint256'], [addressTo, web3.utils.toBN(valueToTransfer)]).toString('hex');

// get the number of transactions sent so far so we can create a fresh nonce
web3.eth.getTransactionCount(addressFrom)
  .then((txCount, err) => {
    // construct the transaction data
    const txData = {
      nonce: web3.utils.toHex(txCount),
      gasLimit: web3.utils.toHex(250000),
      gasPrice: web3.utils.toHex(10e9), // 10 Gwei
      to: tokenAddress,
      from: addressFrom,
      value: '0x00',
      data: `0x${rawData}`,
    };

    const privateKey = Buffer.from(privKey, 'hex');
    const transaction = new Tx(txData);
    transaction.sign(privateKey);
    const serializedTx = transaction.serialize().toString('hex');
    web3.eth.sendSignedTransaction('0x' + serializedTx).on('receipt', console.log);
  });