Download file without extra libraries

download-file.js

var http      = require("http");
var fs        = require("fs");

function getFile(url, saveFile, cb) {
    var request = http.get(url, response => {
        var write$ = fs.createWriteStream(saveFile);
        write$.on("error", cb);
        write$.on("finish", () => cb(null));

        response.pipe(write$);
    });
    request.on("error", cb);
}

// Get assets for the 
// getFile("http://i3.ytimg.com/vi/J---aiyznGQ/mqdefault.jpg", "./tmp/test.jpg", err => {
//     if (err) console.log(err);
// });