Script to convert a Rails/Redmine plugin to a RubyGem

plugin_to_gem.rb

#!/usr/bin/env ruby
# Usage:
#  ruby plugin_to_gem.rb my_plugin_directory
require 'fileutils'

@plugin_dir = ARGV[0]
@plugin_name = ARGV[0]

def rakefile_content
  description = 'TODO'
  redmine_init_content = File.read('init.rb')
  if redmine_init_content.match(/description (.*$)/)
    description = $1.gsub("'",'').gsub('"','')
  end

  content =<<-EORAKE
begin
  require 'jeweler'
  Jeweler::Tasks.new do |s|
    s.name = "#{@plugin_name}"
    s.summary = "#{description}"
    s.email = "edavis@littlestreamsoftware.com"
    s.homepage = "https://projects.littlestreamsoftware.com/projects/TODO"
    s.description = "#{description}"
    s.authors = ["Eric Davis"]
    s.rubyforge_project = "#{@plugin_name}" # TODO
    s.files =  FileList[
                        "[A-Z]*",
                        "init.rb",
                        "rails/init.rb",
                        "{bin,generators,lib,test,app,assets,config,lang}/**/*",
                        'lib/jeweler/templates/.gitignore'
                       ]
  end
  Jeweler::GemcutterTasks.new
  Jeweler::RubyforgeTasks.new do |rubyforge|
    rubyforge.doc_task = "rdoc"
  end
rescue LoadError
  puts "Jeweler, or one of its dependencies, is not available. Install it with: sudo gem install technicalpickles-jeweler -s http://gems.github.com"
end

EORAKE
end

FileUtils.cd(@plugin_dir, :verbose => true) do |dir|
  system('rake clean')
  system('git status')
  system('git checkout master')
  system('git merge origin/master')
  system('git checkout -b gem')

  # Rakefile
  File.open('Rakefile','a') do |file|
    file.puts(rakefile_content)
  end
  system('git commit -am "Updated rakefile for jeweler"')

  # VERSION
  File.open('VERSION','w') do |version_file|
    redmine_init_content = File.read('init.rb')
    if redmine_init_content.match(/version (.*$)/)
      version = $1.gsub("'",'').gsub('"','')
      version_file.puts version
    end
  end
  system('git add VERSION')
  system('git commit -am "Added Version file"')

  # Rails GemPlugin init.rb
  FileUtils.mkdir_p('rails')
  system('git mv init.rb rails/init.rb')
  File.open('init.rb','w') do |init_file|
    init_file.puts('require File.dirname(__FILE__) + "/rails/init"')
  end
  system('git add init.rb')
  system('git commit -am "Added init file for Rails GemPlugin"')



  # Gemspec
  system('rake gemspec')
  system("git add #{@plugin_name}.gemspec")
  system('git commit -am "Added generated gemspec"')

  # Install to test
  system('rake install')

  # Back to master to allow merging
  system('git checkout master')
end