callbackHell.js

// Callback Hell. You and I both know it's hell.
// Here's a secret: Escape Callback Hell...
// ... by using classes, you fucking jackass.

// This is shit:

fs.readdir('tmp', function(err, list) {
    async.map(list, function(item, cb) {
        cb(null, item.toUpperCase());
    }, function(err, results) {
        console.log(results);
    });
});

// This is how it has always supposed to be done

function LoudFiles() {
    fs.readdir('tmp', this.dir.bind(this));
}

LoudFiles.prototype.dir = function(err, list) {
    if (err) {
        return console.error(err);
    }
    
    async.map(list, this.embiggen.bind(this), this.results.bind(this));
};

LoudFiles.prototype.embiggen = function(item, callback) {
    callback(null, item.toUpperCase());
};

LoudFiles.prototype.results = function(err, results) {
    console.log(results);
};

var loud = new LoudFiles();

// Now, don't let me see you fuck around anymore.