escrow-bitcoin/lib/transaction.js

A service to make possible escrow transactions using BTC (Bitcoin)

const explorers = require('bitcore-explorers');
const bitcore = require("bitcore-lib");

/**
 * Make a bitcoin transaction 
 * 
 * @param {Address} addressFrom - Address to withdraw
 * @param {PrivateKey} privateKeyFrom - PrivateKey from Address to withdraw to sign transaction
 * @param {Address} addressTo - Address to send
 * @param {Number} amount - Amount (in satoshis)
 * @param {Networks} [network=bitcore.Networks.testnet] - Network to make transaction
 * @returns string (transaction id)
 */
function Transaction(addressFrom, privateKeyFrom, addressTo, amount, network = bitcore.Networks.testnet) {
    return new Promise(function (resolve, reject) {
        const insight = new explorers.Insight(network);
        insight.getUnspentUtxos(addressFrom, function (err, utxos) {
            if (err) {
                reject(err)
            } else {
                if (utxos.length == 0) {
                    return reject(new Error("if no transactions have happened, there is no balance on the address"))
                }
                var transaction = new bitcore.Transaction()
                    .from(utxos)
                    .to(addressTo, amount)
                    .change(addressFrom)
                    .sign(privateKeyFrom);
                insight.broadcast(transaction, function (error, body) {
                    if (error) {
                        reject(error)
                    } else {
                        resolve(body)
                    }
                });
            }
        });
    })
}

module.exports = Transaction;