Node.js Convert file in base64 code to original file

 var fs = require('fs');

var base64 = 'MTIz'; // String with ZIP source in base64.

var path = './original.zip'

    , buffer = new Buffer(base64, 'base64');

fs.open(path, 'w', function (error, file) {

    if (error) {

        throw 'Error opening file: ' + error;

    }

    fs.write(file, buffer, 0, buffer.length, null, function (error) {

        if (error) throw 'Error writing file: ' + error;

        fs.close(file, function () {

            console.log('File written');

        })

    });

});