Command line script to compress & combine javascript files using the google closure compiler. "sources" needs to be a plain text file with urls of each javascript file to compress on a new line, comments are fine.

min.rb

require 'rubygems'
require 'rest_client'

sources = "sources"
output = "scripts.min.js"

output_path = (File.expand_path(File.dirname(__FILE__))) + "/" + output
sources_path = (File.expand_path(File.dirname(__FILE__))) + "/" + sources

# TODO: only open file if no errors, maybe save a tmp file, then copy it over the real one?
js = File.new(output_path, "w")

# write credits at the top
js.write("\n/*\n * " + output + " generated by min.rb \n * " + Time.new.inspect + "\n */\n")

File.new(sources_path).readlines.each do |line|
  
  next if line.match(/^#/) # skip comments
  
  # compress javascript
  if line.match(/\.js$/)
    
    puts "compressing: " + line 
    
    response = RestClient.post("http://closure-compiler.appspot.com/compile", {
      :code_url => line, 
      :compilation_level => "SIMPLE_OPTIMIZATIONS", 
      :output_format => "text", 
      :output_info => "compiled_code"
    })
    
    # save the compressed js if no errors were thrown
    unless response.match(/^Error/)
      js.write("\n// " + File.basename(line) + "// source: " + line + response)
    else
      puts response
    end
  
  end
  
  # TODO: compress css
  if line.match(/\.css$/)
    puts "no css support yet, skipping " + line
  end
  
end

puts "result: " + output_path