NodeJS - Read in a json file asynchronously

readJsonFileAsync.js

/*
 * @param {String} filepath
 * @param {function} callback function(err, data){}
 */
function readJsonFileAsync(filepath, callback) {
    var fs = require('fs');
    fs.readFile(filepath, 'utf-8', function(err, data) {
        if (err) { callback(err, null); }
        else {
            result = JSON.parse(data);
            if (result) {
                callback(null, result);
            } else {
                callback('parse error', null);
            }
        }
    });
}