callback, promise, async in JS

main.js

var request = require('request');

function requestUrl(url) {
    return new Promise((resolve, reject) => {
        request(url, (error, response, body) => {
            if (error) {
                reject(error);
            } else {
                resolve(response);
            }
        })
    });
}

(async () => {
    const result = await requestUrl('http://www.google.com');
    console.log('HEY');

    // console.log(result);
    console.log('HEY');
})();

// console.log('-> result: ', result);

// const result = requestUrl('http://www.google.com');

// console.log("=> Got promise!");
// console.log('Before: ', promise);

// promise.then(response => {
//     console.log("-> inside: ");
//     console.log('Real : ', promise);
// }).catch(e => console.log(e));

// console.log('After: ', promise);


// request('http://www.google.com', callback);
// function callback(error, response, body) {
//     console.log('error:', error); // Print the error if one occurred
//     console.log('statusCode:', response && response.statusCode); // Print the response status code if a response was received
//     console.log('body:', body); // Print the HTML for the Google homepage.
// }

// var promise1 = new Promise(function(resolve, reject) {
//     setTimeout(function() {
//       resolve('foo');
//     }, 300);
//   });