problem.md

Write an HTTP server that receives only POST requests and converts incoming POST body characters to upper-case and returns it to the client.

Your server should listen on the port provided by the first argument to your program.

---

HINTS

While you're not restricted to using the streaming capabilities of the request and response objects, it will be much easier if you do.

There are a number of different packages in npm that you can use to "transform" stream data as it's passing through. For this exercise the through2-map package offers the simplest API.

through2-map allows you to create a transform stream using only a single function that takes a chunk of data and returns a chunk of data. It's designed to work much like Array#map() but for streams:

var map = require('through2-map')
inStream.pipe(map(function (chunk) {
  return chunk.toString().split('').reverse().join('')
})).pipe(outStream)

In the above example, the incoming data from inStream is converted to a String (if it isn't already), the characters are reversed and the result is passed through to outStream. So we've made a chunk character reverser! Remember though that the chunk size is determined up-stream and you have little control over it for incoming data.

To install through2-map type:

$ npm install through2-map

If you don't have an Internet connection, simply make a node_modules directory and copy the entire directory for the module you want to use from inside the {appname} installation directory:

{rootdir:/node_modules/through2-map}

Documentation for through2-map has been installed along with {appname} on your system and you can read them by pointing your browser here:

{rootdir:/docs/through2-map.html}

---