just study code. url file health checker.

fileChecker.js

// it just study code...

const axios = require('axios');

module.exports = {
/**
 * check url file health. if request return 40X code, then chacker return false.  
 * @param {string} targetUrl target url string
 * @param {object} headerInfo header info  
 * @returns {object} return object {result : (boolean)fileHealth, info : (object)headerInfo}
 */
    checkerFile : function (targetUrl, headerInfo) {
        let resultInfo = {
            result : false,
            info : null
        };
        axios.head(targetUrl, {
            headers : header
        }).then(response => {
            resultInfo.result = true;
            resultInfo.info = response;
            return resultInfo;
        }).catch(err => {
            resultInfo.info = err;
            return resultInfo;
        })
    }
}