Watch both Sass and Coffee files and compile on change (for Node.js)

Cakefile

###
  Modified from https://github.com/jashkenas/coffee-script/blob/master/Cakefile

  Part of an upcoming PeepCode screencast. This snippet is MIT Licensed.
###

{spawn, exec} = require 'child_process'

task 'assets:watch', 'Watch source files and build JS & CSS', (options) ->
  runCommand = (name, args) ->
    proc =           spawn name, args
    proc.stderr.on   'data', (buffer) -> console.log buffer.toString()
    proc.stdout.on   'data', (buffer) -> console.log buffer.toString()
    proc.on          'exit', (status) -> process.exit(1) if status != 0

  runCommand 'sass', ['--watch', 'public/css/sass:public/css']
  runCommand 'coffee',  ['-wc', 'public/js', 'test-js']