Cakefile

fs = require 'fs'
{spawn, exec} = require 'child_process'


closureCompile = (mode, srcPath, destPath, callback = (->)) ->
  modeArgs = {
      pretty: ['--compilation_level', 'WHITESPACE_ONLY',
                 '--formatting', 'PRETTY_PRINT'],
      simple:   ['--compilation_level', 'SIMPLE_OPTIMIZATIONS'],
      advanced: ['--compilation_level', 'ADVANCED_OPTIMIZATIONS'],
  }[mode]
  args = [
    '/usr/bin/env',
    'java',
    '-jar', process.env['CLOSURE_JAR']
  ]
  for x in modeArgs
    args.push x
  args.push '--create_source_map', "#{destPath}.mapping"
  
  exec "cat #{srcPath} | /usr/bin/env #{args.join(' ')} > #{destPath}", (e, out, err) ->
    if e
      console.log out
      console.log err
    callback()


task 'build', () ->
  
  # foo.js
  exec "coffee -c .", () ->
    
    # Got cores?
    closureCompile 'pretty', 'foo.js', 'foo.pretty.js'
    closureCompile 'simple', 'foo.js', 'foo.simple.js', () ->
      closureCompile 'pretty', 'foo.simple.js', 'foo.simple.pretty.js'
    closureCompile 'advanced', 'foo.js', 'foo.advanced.js', () ->
      closureCompile 'pretty', 'foo.advanced.js', 'foo.advanced.pretty.js'

foo.js

(function() {
  var doubler, f, g;
  doubler = function(x) {
    return 2 * x;
  };
  g = function() {
    return JSON.parse("Ceci n'est pas JSON");
  };
  f = function() {
    var x, y;
    x = 1 + 2 + 3;
    y = 4 + g() + doubler(1);
    return x + y;
  };
  if (typeof window !== "undefined" && window !== null) {
    window.x = f();
  } else {
    exports.x = f();
  }
}).call(this);

foo.simple.js

(function(){var b,a,c;b=function(a){return 2*a};c=function(){return JSON.parse("Ceci n'est pas JSON")};a=function(){return 6+(4+c()+b(1))};typeof window!=="undefined"&&window!==null?window.x=a():exports.x=a()}).call(this);

foo.simple.js.mapping

{
"version":2,
"file":"foo.simple.js.mapping",
"lineCount":1,
"lineMaps":["gCEBQBABA/ACA+ADECA/cCABABA/ACUBEBA/ACA9EFA/cCEBABUBQDU/A/!AUDA9A+EHA/cCEBABUBEBE/ACA+AEE/A9AGA/ACA+A7A/YKYBI+oDE9UEI8MFA7UHE/A6AJE/A4YLE/A2ANE/B/QA+Q/A/NA2B/K"],
"mappings":[[0,20,7],
[0,20,1,0],
[0,1,9],
[0,1,9],
[0,1,12],
[0,2,6,1],
[0,2,15,2],
[0,2,18,3],
[0,3,2],
[0,3,2,1],
[0,3,20,1],
[0,3,20],
[0,3,21,4],
[0,3,24],
[0,4,4],
[0,4,11],
[0,4,15,4],
[0,6,2],
[0,6,2,3],
[0,6,14,3],
[0,6,14],
[0,6,17],
[0,7,4],
[0,7,21],
[0,7,11,5],
[0,7,11,6],
[0,7,22],
[0,9,2],
[0,9,2,2],
[0,9,14,2],
[0,9,14],
[0,9,17],
[0,13,4],
[0,11,14,4],
[0,12,8],
[0,12,13],
[0,12,12,3],
[0,12,25],
[0,12,18,1],
[0,12,26],
[0,15,2],
[0,15,6],
[0,15,13,7],
[0,15,24],
[0,15,39,7],
[0,15,50],
[0,16,4,4],
[0,16,4,7],
[0,16,16],
[0,16,15,2],
[0,18,4,4],
[0,18,4,8],
[0,18,17],
[0,18,16,2],
[0,20,8],
],
"sources":["stdin"],
"names":["call","doubler","f","g","x","parse","JSON","window","exports"]
}