gistfile1.coffee

fs = require 'fs'
{Transform} = require 'stream'

class Reverser extends Transform
  _transform: (data, encoding, done) ->
    @push data.toString().split('').reverse().join ''
    done()

class UpperCaser extends Transform
  _transform: (data, encoding, done) ->
    @push data.toString().toUpperCase()
    done()

textTransformer = ->
  reverser = new Reverser
  reverser.pipe new UpperCaser
  reverser

fileReadStream = fs.createReadStream 'package.json'

fileReadStream.pipe fs.createWriteStream 'package.json.backup'
fileReadStream
  .pipe(textTransformer())
  .pipe(process.stdout)