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.
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 learnyounode installation directory:
Documentation for through2-map has been installed along with learnyounode on your system and you can read them by pointing your browser here: