utils.js

const axios = require('axios');
const { parseUnits, formatUnits } = require('ethers').utils;

function notUndefined(para) {
    if (typeof para === 'undefined') {
        return false;
    }
    return true;
}

const sleepMs = (ms) => new Promise((res) => setTimeout(res, ms));
const axiosConfig = {
    headers: {
        'Content-Type': 'application/json',
    },
};

async function getUrlRequest(queryURL, defaultResponse) {
    let response;

    try {
        response = await axios.get(queryURL);
        if (response.statusCode < 200 || response.statusCode > 299) {
            return defaultResponse;
        }
    } catch (err) {
        console.log('axios.get() EXCEPTION:');
        return defaultResponse;
    }

    if (notUndefined(response.data)) {
        return response.data;
    } else {
        console.log('getPassword() ERROR: ' + JSON.stringify(response.data));
        return defaultResponse;
    }
}

async function postUrlRequest(queryURL, payload, defaultResponse) {
    let response;

    try {
        response = await axios.post(queryURL, payload, axiosConfig);
        if (response.statusCode < 200 || response.statusCode > 299) {
            return defaultResponse;
        }
    } catch (err) {
        console.log('axios.post() EXCEPTION:');
        return defaultResponse;
    }

    if (notUndefined(response.data)) {
        return response.data;
    } else {
        console.log('getPassword() ERROR: ' + JSON.stringify(response.data));
        return defaultResponse;
    }
}

// Do NOT access it frequently, otherwise request might be blocked
async function getGasPrice(debug) {
    const defaultGasPrice = {
        code: 200,
        data: {
            rapid: parseUnits('122', 'gwei'),
            fast: parseUnits('116', 'gwei'),
            standard: parseUnits('100', 'gwei'),
            slow: parseUnits('93', 'gwei'),
            timestamp: new Date('2021-04-15T00:59:04.593Z').getTime(),
        },
    };
    // Alternative: https://docs.ethgasstation.info/gas-price
    // https://ethgasstation.info/api/ethgasAPI.json?api-key=XXAPI_Key_HereXXX
    // ***Note: To convert the provided values to gwei, divide by 10.***

    // https://taichi.network/#gasnow
    const queryURL = 'https://www.gasnow.org/api/v3/gas/price?utm_source=:AutomaticTraders';
    const resonse = await getUrlRequest(queryURL, defaultGasPrice);
    const priceList = resonse.data;
    // console.log(priceList);
    if (debug) {
        console.log('gas price', {
            rapid: formatUnits(priceList.rapid, 'gwei'),
            fast: formatUnits(priceList.fast, 'gwei'),
            standard: formatUnits(priceList.standard, 'gwei'),
            slow: formatUnits(priceList.slow, 'gwei'),
        });
    }
    return priceList;
}

module.exports = {
    notUndefined,
    sleepMs,
    getUrlRequest,
    postUrlRequest,
    getGasPrice,
};