Proguard plugin for Apache Buildr

proguard.rb

#
# Usage:
#
#  Add the following at the top of your buildfile,
#
#     require 'proguard.rb'
#
#  And specify your proguard jar in your project,
#
#   package(:proguard).tap do |proguard|
#     proguard.keep << 'class Hello'
#     # other options ...
#   end
#

module Buildr
  module Proguard

    REQUIRES = [ "net.sf.proguard:proguard-base:jar:4.8" ]

    Java.classpath << lambda { REQUIRES }

    class ProguardTask < Rake::FileTask

      attr_accessor :dependencies
      attr_accessor :libraries
      attr_accessor :keep

      def initialize(*args)
        super

        @dependencies ||= []
        @keep ||= []

        rt_jar ||= begin
          home = ENV['JAVA_HOME'] or fail 'Are we forgetting something? JAVA_HOME not set.'
          ['jre/lib/rt.jar', '../lib/rt.jar'].map { |path| File.expand_path(path, home) }.find { |path| File.exist?(path) }
        end

        @libraries ||= [rt_jar]

        enhance do
          Java.load

          cmd_args = [
            '-libraryjars', libraries.join(File::PATH_SEPARATOR),
            '-injars', dependencies.join(File::PATH_SEPARATOR),
            '-outjar', self.to_s,
            '-keep', Array(keep).join(",")
          ]
          trace "ProGuard.main #{cmd_args.inspect}"
          Java.proguard.ProGuard.main(cmd_args.to_java(Java.java.lang.String))

        end
      end
    end
  end

  def package_as_proguard(file_name)
    Proguard::ProguardTask.define_task(file_name).tap do |proguard|
      proguard.dependencies = [compile.target]
    end
  end

  def package_as_proguard_spec(spec) #:nodoc:
    spec.merge(:type => :jar)
  end

  class Project
    include Proguard
  end
end