gistfile1.rb

#!/usr/bin/env ruby
%w[rubygems sinatra jsmin cssmin].each{|l| require l}

configure do
  set :bundle, 'bundle'
end

configure :development do
  set :js_proc, proc {|f| "\n/* '#{f}' */\n" + File.read(f)}
  set :css_proc, proc {|f| "\n/* '#{f}' */\n" +File.read(f)}
end
configure :production do
  set :js_proc,
      proc{|f|"/* '#{File.basename(f)}' */\n" + JSMin.minify(File.read(f))}
  set :css_proc,
      proc{|f| "/* '#{File.basename(f)}' */\n"+ CSSMin.minify(File.read(f))}
end

def bundle(name, *files)
  # All the needed variables
  format = name.sub!(/.*\.(.*)$/, $1)
  file   = "#{options.public}/#{options.bundle}/#{files.join(',')}.#{format}"

  # Now, we read each file and concatenate it in an array
  files.map! { |f| options.public + "/#{f}.#{format}"} \
       .map! { |f| options.send("#{format}_proc",f)  }.join("\n")

  # If it does not exist
  dir = File.dirname(file)
  FileUtils.mkdir_p(dir) unless File.exists?(dir)
  File.open(file, 'w+').write(files)
end