1 files changed, 18 insertions, 18 deletions
diff --git a/railties/lib/rails.rb b/railties/lib/rails.rb
index bb98bbe5bf..e7172e491f 100644
--- a/railties/lib/rails.rb
+++ b/railties/lib/rails.rb
@@ -3,12 +3,13 @@ require 'rails/ruby_version_check'
 require 'pathname'
 
 require 'active_support'
+require 'active_support/dependencies/autoload'
 require 'active_support/core_ext/kernel/reporting'
+require 'active_support/core_ext/module/delegation'
 require 'active_support/core_ext/array/extract_options'
 
 require 'rails/application'
 require 'rails/version'
-require 'rails/deprecation'
 
 require 'active_support/railtie'
 require 'action_dispatch/railtie'
@@ -20,24 +21,27 @@ silence_warnings do
 end
 
 module Rails
-  autoload :Info, 'rails/info'
-  autoload :InfoController,    'rails/info_controller'
-  autoload :WelcomeController, 'rails/welcome_controller'
+  extend ActiveSupport::Autoload
+
+  autoload :Info
+  autoload :InfoController
+  autoload :MailersController
+  autoload :WelcomeController
 
   class << self
-    attr_accessor :application, :cache, :logger
+    @application = @app_class = nil
 
-    # The Configuration instance used to configure the Rails environment
-    def configuration
-      application.config
+    attr_writer :application
+    attr_accessor :app_class, :cache, :logger
+    def application
+      @application ||= (app_class.instance if app_class)
     end
 
-    def initialize!
-      application.initialize!
-    end
+    delegate :initialize!, :initialized?, to: :application
 
-    def initialized?
-      application.initialized?
+    # The Configuration instance used to configure the Rails environment
+    def configuration
+      application.config
     end
 
     def backtrace_cleaner
@@ -76,16 +80,12 @@ module Rails
       env = Rails.env
       groups.unshift(:default, env)
       groups.concat ENV["RAILS_GROUPS"].to_s.split(",")
-      groups.concat hash.map { |k,v| k if v.map(&:to_s).include?(env) }
+      groups.concat hash.map { |k, v| k if v.map(&:to_s).include?(env) }
       groups.compact!
       groups.uniq!
       groups
     end
 
-    def version
-      VERSION::STRING
-    end
-
     def public_path
       application && Pathname.new(application.paths["public"].first)
     end