ABIUtils.js

var Tx = require('ethereumjs-tx');

function makeRawTransaction(msgData, msgSender, hexPrivateKey, contractAddress) {
    var tx = new Tx({
        nonce: web3.toHex(web3.eth.getTransactionCount(msgSender)),
        gasPrice: web3.toHex(web3.toWei('20', 'gwei')),
        gasLimit: 1000000,
        to: contractAddress,
        value: 0,
        data: msgData,
    });
    var privateKey = Buffer.from(hexPrivateKey, 'hex');
    tx.sign(privateKey);
    var raw = '0x' + tx.serialize().toString('hex');
    return raw
}

function sendRawTransaction(raw) {
    return new Promise(function (resolve, reject) {
        web3.eth.sendRawTransaction(raw, function (err, transactionHash) {
            if (err !== null) return reject(err);
            resolve(transactionHash);
        });
    });
}

function functionSignature(methodName) {
    return web3.sha3(methodName).substr(0, 2 + 8);
}

function encodeAddress(address) {
    address = address.substr(2, address.length - 2);
    while (address.length < 64) address = "0" + address;
    return address;
}

function encodeUint(value) {
    value = value.toString(16);
    while (value.length < 64) value = "0" + value;
    return value;
}

// Create ABI calls for functions
function msgData0(methodName, value) {
    return functionSignature(methodName) + encodeUint(value);
}

function msgData(methodName, addressValue) {
    return functionSignature(methodName) + encodeAddress(addressValue);
}

function msgData1(methodName, address, value) {
    return functionSignature(methodName) + encodeAddress(address) + encodeUint(value);
}

function msgData2(methodName, address1, address2, value) {
    return functionSignature(methodName) + encodeAddress(address1) + encodeAddress(address2) + encodeUint(value);
}

function msgData3(methodName, address1, value1, address2, value2) {
    return functionSignature(methodName) + encodeAddress(address1) + encodeUint(value1) + encodeAddress(address2) + encodeUint(value2);
}

module.exports = {
    makeRawTransaction: makeRawTransaction,
    sendRawTransaction: sendRawTransaction,
    functionSignature: functionSignature,
    encodeAddress: encodeAddress,
    encodeUint: encodeUint,
    msgData0: msgData0,
    msgData: msgData,
    msgData1: msgData1,
    msgData2: msgData2,
    msgData3: msgData3
};