sprocketize.rb

#!/usr/bin/env ruby
require 'rubygems'
require 'Sprockets'
require 'Jsmin'
 
MINFILE = 'app/webroot/js/build-min.js'
CONCATFILE = 'app/webroot/js/concat.js'
 
secretary = Sprockets::Secretary.new(
  :asset_root => 'app/webroot',
  :load_path => ['app/webroot/js', 'plugins/*/vendors/js/**', 'app/plugins/*/vendors/js/**'],
  :source_files => ['app/webroot/js/*.js', 'plugins/*/vendors/js/**/*.js', 'app/plugins/*/vendors/js/**/*.js'],
  :strip_comments => true
)
 
# generate the concatenation object
concatenation = secretary.concatenation
 
# write to disk
gluedFiles = concatenation.to_s
concatenation.save_to(CONCATFILE)
 
# Run through JSMin
File.open(MINFILE, 'w') { |file| file.write(JSMin.minify(gluedFiles)) }

Plugin paths to js files was updated in CakePHP 1.3. This example is for CakePHP 1.2