module Rails::ConsoleMethods

def app(create = false)

instance, pass a non-false value as the parameter.
reference the global "app" instance, created on demand. To recreate the 
def app(create = false)
  @app_integration_instance = nil if create
  @app_integration_instance ||= new_session
end

def controller

This method assumes an +ApplicationController+ exists, and that it extends ActionController::Base.

Gets a new instance of a controller object. 
def controller
  @controller ||= ApplicationController.new
end

def helper

This method assumes an +ApplicationController+ exists, and that it extends ActionController::Base.

Gets the helper methods available to the controller. 
def helper
  ApplicationController.helpers
end

def new_session

to the block before being returned.
create a new session. If a block is given, the new session will be yielded 
def new_session
  app = Rails.application
  session = ActionDispatch::Integration::Session.new(app)
  # This makes app.url_for and app.foo_path available in the console
  session.extend(app.routes.url_helpers)
  session.extend(app.routes.mounted_helpers)
  session
end

def reload!(print = true)

reloads the environment 
def reload!(print = true)
  puts "Reloading..." if print
  Rails.application.reloader.reload!
  true
end