AWS API Gateway UTF-8 (unicode) workaround

aws API Gateway unicode workaround base64-util.js

// inspiration
// http://timnew.me/blog/2013/01/30/pitfall-in-node-crypto-and-base64-encoding/
// https://github.com/kevva/base64-regex
Base64Util = {
  encode64: function(text) {
    return new Buffer(text, 'utf8').toString('base64');
  },
  decode64: function(base64) {
    return new Buffer(base64, 'base64').toString('utf8');
  },
  test: function(base64) {
	var regex = '^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$';
	return new RegExp(regex).test(base64);
  } 
}; 

event.json

{
  "data": "YWJjw6XDpsO4"
}

lambda.js

// event.json:  'abcåæø' <-> 'YWJjw6XDpsO4'

require('base64-util.js)
var Base64 = new Base64Util();
exports.handler = function (event, context) {
    var data = event.data;
    if (Base64.test(event.data)) {
        data = Base64.decode64(event.data);
    }
    // your code 
}

playground.swift

//: Playground - noun: a place where people can play
// iOS Swift example for encoding to base64

import UIKit
import Foundation

var s : NSString = "abcåæø"
let data = s.dataUsingEncoding(NSUTF8StringEncoding)
let s64 = data?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)