3 files changed, 153 insertions, 0 deletions
diff --git a/railties/lib/rails/engine/commands.rb b/railties/lib/rails/engine/commands.rb
new file mode 100644
index 0000000000..f39f926109
--- /dev/null
+++ b/railties/lib/rails/engine/commands.rb
@@ -0,0 +1,41 @@
+ARGV << '--help' if ARGV.empty?
+
+aliases = {
+  "g" => "generate",
+  "d" => "destroy"
+}
+
+command = ARGV.shift
+command = aliases[command] || command
+
+require ENGINE_PATH
+engine = ::Rails::Engine.find(ENGINE_ROOT)
+
+case command
+when 'generate', 'destroy'
+  require 'rails/generators'
+  Rails::Generators.namespace = engine.railtie_namespace
+  engine.load_generators
+  require "rails/commands/#{command}"
+
+when '--version', '-v'
+  ARGV.unshift '--version'
+  require 'rails/commands/application'
+
+else
+  puts "Error: Command not recognized" unless %w(-h --help).include?(command)
+  puts <<-EOT
+Usage: rails COMMAND [ARGS]
+
+The common Rails commands available for engines are:
+ generate    Generate new code (short-cut alias: "g")
+ destroy     Undo code generated with "generate" (short-cut alias: "d")
+
+All commands can be run with -h for more information.
+
+If you want to run any commands that need to be run in context
+of the application, like `rails server` or `rails console`,
+you should do it from application's directory (typically test/dummy).
+  EOT
+  exit(1)
+end
diff --git a/railties/lib/rails/engine/configuration.rb b/railties/lib/rails/engine/configuration.rb
new file mode 100644
index 0000000000..10d1821709
--- /dev/null
+++ b/railties/lib/rails/engine/configuration.rb
@@ -0,0 +1,91 @@
+require 'rails/railtie/configuration'
+
+module Rails
+  class Engine
+    class Configuration < ::Rails::Railtie::Configuration
+      attr_reader :root
+      attr_writer :middleware, :eager_load_paths, :autoload_once_paths, :autoload_paths
+
+      def initialize(root=nil)
+        super()
+        @root = root
+        @generators = app_generators.dup
+      end
+
+      # Returns the middleware stack for the engine.
+      def middleware
+        @middleware ||= Rails::Configuration::MiddlewareStackProxy.new
+      end
+
+      # Holds generators configuration:
+      #
+      #   config.generators do |g|
+      #     g.orm             :data_mapper, migration: true
+      #     g.template_engine :haml
+      #     g.test_framework  :rspec
+      #   end
+      #
+      # If you want to disable color in console, do:
+      #
+      #   config.generators.colorize_logging = false
+      #
+      def generators #:nodoc:
+        @generators ||= Rails::Configuration::Generators.new
+        yield(@generators) if block_given?
+        @generators
+      end
+
+      def paths
+        @paths ||= begin
+          paths = Rails::Paths::Root.new(@root)
+
+          paths.add "app",                 eager_load: true, glob: "*"
+          paths.add "app/assets",          glob: "*"
+          paths.add "app/controllers",     eager_load: true
+          paths.add "app/helpers",         eager_load: true
+          paths.add "app/models",          eager_load: true
+          paths.add "app/mailers",         eager_load: true
+          paths.add "app/views"
+
+          paths.add "app/controllers/concerns", eager_load: true
+          paths.add "app/models/concerns",      eager_load: true
+
+          paths.add "lib",                 load_path: true
+          paths.add "lib/assets",          glob: "*"
+          paths.add "lib/tasks",           glob: "**/*.rake"
+
+          paths.add "config"
+          paths.add "config/environments", glob: "#{Rails.env}.rb"
+          paths.add "config/initializers", glob: "**/*.rb"
+          paths.add "config/locales",      glob: "*.{rb,yml}"
+          paths.add "config/routes.rb"
+
+          paths.add "db"
+          paths.add "db/migrate"
+          paths.add "db/seeds.rb"
+
+          paths.add "vendor",              load_path: true
+          paths.add "vendor/assets",       glob: "*"
+
+          paths
+        end
+      end
+
+      def root=(value)
+        @root = paths.path = Pathname.new(value).expand_path
+      end
+
+      def eager_load_paths
+        @eager_load_paths ||= paths.eager_load
+      end
+
+      def autoload_once_paths
+        @autoload_once_paths ||= paths.autoload_once
+      end
+
+      def autoload_paths
+        @autoload_paths ||= paths.autoload_paths
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails/engine/railties.rb b/railties/lib/rails/engine/railties.rb
new file mode 100644
index 0000000000..9969a1475d
--- /dev/null
+++ b/railties/lib/rails/engine/railties.rb
@@ -0,0 +1,21 @@
+module Rails
+  class Engine < Railtie
+    class Railties
+      include Enumerable
+      attr_reader :_all
+
+      def initialize
+        @_all ||= ::Rails::Railtie.subclasses.map(&:instance) +
+          ::Rails::Engine.subclasses.map(&:instance)
+      end
+
+      def each(*args, &block)
+        _all.each(*args, &block)
+      end
+
+      def -(others)
+        _all - others
+      end
+    end
+  end
+end