convert.js

/*global require, module */
var aws = require('aws-sdk');
module.exports = function convert(bucket, fileKey, callback) {
	'use strict';
	var s3 = new aws.S3(),
		Transform = require('stream').Transform,
		uppercase = new Transform({decodeStrings: false}),
		stream;
	uppercase._transform = function (chunk, encoding, done) {
		done(null, chunk.toUpperCase());
	};
	stream = s3.getObject({
		Bucket: bucket,
		Key: fileKey
	}).createReadStream();
	stream.setEncoding('utf8');
	stream.pipe(uppercase);
	s3.upload({
		Bucket: bucket,
		Key: fileKey.replace(/^in/, 'out'),
		Body: uppercase,
		ACL: 'private'
	}, callback);

};