cancelPendingTx.js

const Web3 = require("web3");
const Tx = require("ethereumjs-tx");

const acct = "";
const receiver = "";
const chainId = 42;

const privateKey = new Buffer(
  "PRIVATE_KEY",
  "hex"
);
const web3 = new Web3(
  new Web3.providers.HttpProvider(
    "https://kovan.infura.io"
  )
);

const sendRawTx = async function(_rawTx) {
  return new Promise(function(resolve, reject) {
    let tx = new Tx(_rawTx);
    tx.sign(privateKey);
    let serializedTx = tx.serialize();
    console.log("send raw now");

    web3.eth.sendSignedTransaction(
      "0x" + serializedTx.toString("hex"),
      (err, res) => {
        if (!err) {
          resolve(res);
        } else {
          if (
            err.message ===
            "Transaction with the same hash was already imported."
          )
            reject(
              "Please wait for the recent transaction being mined before make another transaction"
            );
          else reject("Cant sendRawTrasaction, message : " + err.message);
        }
      }
    );
  });
};

const getTransactionCount = async function(address) {
  return new Promise(function(resolve, reject) {
    web3.eth.getTransactionCount(address, "latest", (err, res) => {
      if (err) {
        reject(err.message);
      } else {
        resolve(res);
      }
    });
  });
};

async function sendEth(_toAddress, _amount, gasChosen) {
  let txCount;
  try {
    txCount = await getTransactionCount(acct);
    console.log('txCount :', txCount);
    
  } catch (error) {
    console.log("getTransactionCount fail:", txCount, error);
    return {
      error: error
    };
  }

  // console.log('res ether :', txCount, _amount);
  var rawTransaction = {
    from: acct,
    nonce: web3.utils.toHex(txCount),
    gasPrice: parseInt(gasChosen),
    gasLimit: 100000,
    to: _toAddress,
    value: _amount,
    chainId
  };

  // console.log('rawTransaction: ', rawTransaction);
  let withDrawEtherTx;
  try {
    withDrawEtherTx = await sendRawTx(rawTransaction);
    console.log("withDrawEtherTx success:", withDrawEtherTx);
    return withDrawEtherTx;
  } catch (error) {
    console.log("withDrawEtherTx fail:", withDrawEtherTx, error);
    return {
      error: error
    };
  }
}

const gas = 5  10 * 9;
function main() {
  sendEth(receiver, 0, gas);
}

main();