Added 'rails plugin new' generator which generates gem plugin skeleton.

This command is based on enginex gem by José Valim. It generates gem structure
and ads dummy application into test/dummy. This can be used to start developing
any kind of extension for rails 3.

railties/lib/rails/cli.rb

@@ -11,4 +11,9 @@
 require 'rails/ruby_version_check'
 Signal.trap("INT") { puts; exit }
 
-require 'rails/commands/application'
+if ARGV.first == 'plugin'
+  ARGV.shift
+  require 'rails/commands/plugin_new'
+else
+  require 'rails/commands/application'
+end

railties/lib/rails/commands/plugin_new.rb

@@ -0,0 +1,16 @@
+require 'rails/version'
+if %w(--version -v).include? ARGV.first
+  puts "Rails #{Rails::VERSION::STRING}"
+  exit(0)
+end
+
+if ARGV.first != "new"
+  ARGV[0] = "--help"
+else
+  ARGV.shift
+end
+
+require 'rails/generators'
+require 'rails/generators/rails/plugin_new/plugin_new_generator'
+
+Rails::Generators::PluginNewGenerator.start

railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb

@@ -0,0 +1,225 @@
+require "rails/generators/rails/app/app_generator"
+
+module Rails
+  class PluginBuilder
+    def rakefile
+      template "Rakefile"
+    end
+
+    def readme
+      copy_file "README.rdoc"
+    end
+
+    def gemfile
+      template "Gemfile"
+    end
+
+    def license
+      template "MIT-LICENSE"
+    end
+
+    def gemspec
+      template "%name%.gemspec"
+    end
+
+    def gitignore
+      copy_file "gitignore", ".gitignore"
+    end
+
+    def lib
+      directory "lib"
+    end
+
+    def test
+      directory "test"
+    end
+
+    def test_dummy
+      invoke Rails::Generators::AppGenerator,
+        [ File.expand_path(dummy_path, destination_root) ]
+    end
+
+    def test_dummy_config
+      store_application_definition!
+      template "rails/boot.rb", "#{dummy_path}/config/boot.rb", :force => true
+      template "rails/application.rb", "#{dummy_path}/config/application.rb", :force => true
+    end
+
+    def test_dummy_clean
+      inside dummy_path do
+        remove_file ".gitignore"
+        remove_file "db/seeds.rb"
+        remove_file "doc"
+        remove_file "Gemfile"
+        remove_file "lib/tasks"
+        remove_file "public/images/rails.png"
+        remove_file "public/index.html"
+        remove_file "public/robots.txt"
+        remove_file "README"
+        remove_file "test"
+        remove_file "vendor"
+      end
+    end
+
+    def script
+      directory "script" do |content|
+        "#{shebang}\n" + content
+      end
+      chmod "script", 0755, :verbose => false
+    end
+  end
+
+  module Generators
+    class PluginNewGenerator < Base
+      attr_accessor :rails_template
+
+      add_shebang_option!
+
+      argument :plugin_path,            :type => :string
+
+      class_option :builder,            :type => :string, :aliases => "-b",
+                                        :desc => "Path to a plugin builder (can be a filesystem path or URL)"
+
+      class_option :skip_gemfile,       :type => :boolean, :default => false,
+                                        :desc => "Don't create a Gemfile"
+
+      class_option :skip_git,           :type => :boolean, :aliases => "-G", :default => false,
+                                        :desc => "Skip Git ignores and keeps"
+
+      class_option :help,               :type => :boolean, :aliases => "-h", :group => :rails,
+                                        :desc => "Show this help message and quit"
+
+      def self.say_step(message)
+        @step = (@step || 0) + 1
+        class_eval <<-METHOD, __FILE__, __LINE__ + 1
+          def step_#{@step}
+            #{"puts" if @step > 1}
+            say_status "STEP #{@step}", #{message.inspect}
+          end
+        METHOD
+      end
+
+      def initialize(*args)
+        raise Error, "Options should be given after plugin name. For details run: rails plugin --help" if args[0].blank?
+
+        @original_wd = Dir.pwd
+
+        super
+      end
+
+      say_step "Creating gem skeleton"
+
+      def create_root
+        self.destination_root = File.expand_path(plugin_path, destination_root)
+        valid_plugin_const?
+
+        empty_directory '.'
+        FileUtils.cd(destination_root) unless options[:pretend]
+      end
+
+      def create_root_files
+        build(:readme)
+        build(:rakefile)
+        build(:gemspec)
+        build(:license)
+        build(:gitignore) unless options[:skip_git]
+        build(:gemfile)   unless options[:skip_gemfile]
+      end
+
+      def create_config_files
+        build(:config)
+      end
+
+      def create_lib_files
+        build(:lib)
+      end
+
+      def create_script_files
+        build(:script)
+      end
+
+      def create_test_files
+        build(:test) unless options[:skip_test_unit]
+      end
+
+      say_step "Vendoring Rails application at test/dummy"
+
+      def create_test_dummy_files
+        build(:test_dummy)
+      end
+
+      say_step "Configuring Rails application"
+
+      def change_config_files
+        build(:test_dummy_config)
+      end
+
+      say_step "Removing unneeded files"
+
+      def remove_uneeded_rails_files
+        build(:test_dummy_clean)
+      end
+
+    protected
+
+      def self.banner
+        "rails plugin new #{self.arguments.map(&:usage).join(' ')} [options]"
+      end
+
+      def builder
+        @builder ||= begin
+          if path = options[:builder]
+            if URI(path).is_a?(URI::HTTP)
+              contents = open(path, "Accept" => "application/x-thor-template") {|io| io.read }
+            else
+              contents = open(File.expand_path(path, @original_wd)) {|io| io.read }
+            end
+
+            prok = eval("proc { #{contents} }", TOPLEVEL_BINDING, path, 1)
+            instance_eval(&prok)
+          end
+
+          builder_class = defined?(::PluginBuilder) ? ::PluginBuilder : Rails::PluginBuilder
+          builder_class.send(:include, ActionMethods)
+          builder_class.new(self)
+        end
+      end
+
+      def build(meth, *args)
+        builder.send(meth, *args) if builder.respond_to?(meth)
+      end
+
+      def name
+        @name ||= File.basename(destination_root)
+      end
+
+      def camelized
+        @camelized ||= name.gsub(/\W/, '_').squeeze('_').camelize
+      end
+
+      def valid_plugin_const?
+        if camelized =~ /^\d/
+          raise Error, "Invalid plugin name #{name}. Please give a name which does not start with numbers."
+        elsif RESERVED_NAMES.include?(name)
+          raise Error, "Invalid plugin name #{name}. Please give a name which does not match one of the reserved rails words."
+        elsif Object.const_defined?(camelized)
+          raise Error, "Invalid plugin name #{name}, constant #{camelized} is already in use. Please choose another application name."
+        end
+      end
+
+      def dummy_path
+        "test/dummy"
+      end
+
+      def application_definition
+        @application_definition ||= begin
+          unless options[:pretend]
+            contents = File.read(File.expand_path("#{dummy_path}/config/application.rb", destination_root))
+            contents[(contents.index("module Dummy"))..-1]
+          end
+        end
+      end
+      alias :store_application_definition! :application_definition
+    end
+  end
+end

railties/lib/rails/generators/rails/plugin_new/templates/%name%.gemspec

@@ -0,0 +1,9 @@
+# Provide a simple gemspec so you can easily use your
+# project in your rails apps through git.
+Gem::Specification.new do |s|
+  s.name = "<%= name %>"
+  s.summary = "Insert <%= camelized %> summary."
+  s.description = "Insert <%= camelized %> description."
+  s.files = Dir["lib/**/*"] + ["MIT-LICENSE", "Rakefile", "README.rdoc"]
+  s.version = "0.0.1"
+end

railties/lib/rails/generators/rails/plugin_new/templates/Gemfile

@@ -0,0 +1,11 @@
+source "http://rubygems.org"
+
+gem "rails", :git => "http://github.com/rails/rails.git"
+gem "arel" , :git => "http://github.com/rails/arel.git"
+gem "rack" , :git => "http://github.com/rack/rack.git"
+gem "capybara", ">= 0.3.9"
+gem "sqlite3-ruby", :require => "sqlite3"
+
+if RUBY_VERSION < '1.9'
+  gem "ruby-debug", ">= 0.10.3"
+end

railties/lib/rails/generators/rails/plugin_new/templates/MIT-LICENSE

@@ -0,0 +1,20 @@
+Copyright <%= Date.today.year %> YOURNAME
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

railties/lib/rails/generators/rails/plugin_new/templates/README.rdoc

@@ -0,0 +1,3 @@
+= <%= camelized %>
+
+This project rocks and uses MIT-LICENSE.

railties/lib/rails/generators/rails/plugin_new/templates/Rakefile

@@ -0,0 +1,46 @@
+# encoding: UTF-8
+require 'rubygems'
+begin
+  require 'bundler/setup'
+rescue LoadError
+  puts 'You must `gem install bundler` and `bundle install` to run rake tasks'
+end
+
+require 'rake'
+require 'rake/rdoctask'
+require 'rake/gempackagetask'
+
+require 'rake/testtask'
+
+Rake::TestTask.new(:test) do |t|
+  t.libs << 'lib'
+  t.libs << 'test'
+  t.pattern = 'test/**/*_test.rb'
+  t.verbose = false
+end
+
+task :default => :test
+
+Rake::RDocTask.new(:rdoc) do |rdoc|
+  rdoc.rdoc_dir = 'rdoc'
+  rdoc.title    = '<%= camelized %>'
+  rdoc.options << '--line-numbers' << '--inline-source'
+  rdoc.rdoc_files.include('README.rdoc')
+  rdoc.rdoc_files.include('lib/**/*.rb')
+end
+
+spec = Gem::Specification.new do |s|
+  s.name = "<%= name %>"
+  s.summary = "Insert <%= camelized %> summary."
+  s.description = "Insert <%= camelized %> description."
+  s.files =  FileList["[A-Z]*", "lib/**/*"]
+  s.version = "0.0.1"
+end
+
+Rake::GemPackageTask.new(spec) do |pkg|
+end
+
+desc "Install the gem #{spec.name}-#{spec.version}.gem"
+task :install do
+  system("gem install pkg/#{spec.name}-#{spec.version}.gem --no-ri --no-rdoc")
+end

railties/lib/rails/generators/rails/plugin_new/templates/gitignore

@@ -0,0 +1,6 @@
+.bundle/
+log/*.log
+pkg/
+test/dummy/db/*.sqlite3
+test/dummy/log/*.log
+test/dummy/tmp/

railties/lib/rails/generators/rails/plugin_new/templates/lib/%name%.rb.tt

@@ -0,0 +1,2 @@
+module <%= camelized %>
+end

railties/lib/rails/generators/rails/plugin_new/templates/rails/application.rb

@@ -0,0 +1,12 @@
+require File.expand_path('../boot', __FILE__)
+
+require "active_model/railtie"
+require "active_record/railtie"
+require "action_controller/railtie"
+require "action_view/railtie"
+require "action_mailer/railtie"
+
+Bundler.require
+require "<%= name %>"
+
+<%= application_definition %>

railties/lib/rails/generators/rails/plugin_new/templates/rails/boot.rb

@@ -0,0 +1,10 @@
+require 'rubygems'
+gemfile = File.expand_path('../../../../Gemfile', __FILE__)
+
+if File.exist?(gemfile)
+  ENV['BUNDLE_GEMFILE'] = gemfile
+  require 'bundler'
+  Bundler.setup
+end
+
+$:.unshift File.expand_path('../../../../lib', __FILE__)

railties/lib/rails/generators/rails/plugin_new/templates/script/rails.tt

@@ -0,0 +1,5 @@
+#!/usr/bin/env ruby
+# This command will automatically be run when you run "rails" with Rails 3 gems installed from the root of your application.
+
+ENGINE_PATH = File.expand_path('../..',  __FILE__)
+load File.expand_path('../../test/dummy/script/rails',  __FILE__)

railties/lib/rails/generators/rails/plugin_new/templates/test/%name%_test.rb.tt

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class <%= camelized %>Test < ActiveSupport::TestCase
+  test "truth" do
+    assert_kind_of Module, <%= camelized %>
+  end
+end