A JavaScript minifier and dependency loader in Ruby.

js_builder.rb

#!/usr/bin/env ruby

# Notes:
# * Your JS files in the "manifest" will be minified using Google's Closure Compiler
#   and added to the final build in the order listed.
# * Vendor libraries (like jQuery) and the "compiler.jar" must be in your
#   "vendor_lib_path" directory.
# * Write your JS in modules for best results!

# Running file directly
if __FILE__ == $0
  
  ##############################################################################
  # Configuration (YOU EDIT THIS PART!)

  # Source libraries
  # (Vendor libraries are NOT minified, only your source files)
  vendor_libs = ["jquery.min.js", "raphael.min.js"]
  # (Add your JS files here in the order to be loaded)
  # (DO NOT ADD THE .JS EXTENSION)
  manifest = ["file_1", "tests/file_2", "tests/other/file_3"]
  
  # Base paths
  scripts_path = "scripts/"
  vendor_lib_path = "vendor/"
  build_path = "public/js/" # Where you want the final JS build to end up
  
  # Content (add your own copyright or license)
  copyright = <<COPYRIGHT

/**
* My Product
* Your Name (c) 2012, All rights reserved.
*/

COPYRIGHT
  
  ##############################################################################
  # Start compilation (YOU DON'T EDIT THIS PART - UNLESS YOU WANT TO)
  
  # Start the timer
  beginning = Time.now
  
  puts "\n"
  
  # The final build containing all the JS
  js_build = ""
  
  # Load vendor libraries
  vendor_libs.each do |lib|
    js_build << File.read("#{vendor_lib_path}#{lib}") << "\n"
  end
  
  # Example:
  #   "java -jar compiler.jar --js hi.js --js_output_file hi.min.js"
  compiler_cmd = "java -jar #{vendor_lib_path}compiler.jar "
  
  manifest.each do |js_file|
    puts "Adding #{js_file}.js"
    compiler_cmd << "--js #{scripts_path}#{js_file}.js "
  end
  
  puts "\nCompiling...\n"
  
  js_build << copyright
  
  result = IO.popen(compiler_cmd)
  js_build << result.readlines.join
  
  File.open("#{build_path}main-build.js", "w") { |f| f.puts(js_build) }
  
  puts "\nAll done!"
  
  t_elapsed = (Time.now - beginning).round(2)
  puts "Finished in #{t_elapsed} seconds.\n\n"
  
end