How to rename rails 4 app?

Since rails 4.1.x, if you want to rename your application, the only two files you need to modify are config/application.rb:

require File.expand_path('../boot', __FILE__)

require 'rails/all'

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module YourApplicationName # <-- rename it here
   class Application < Rails::Application
     ...
   end
end

and config/initializers/session_store.rb (optional):

# Be sure to restart your server when you modify this file.

Rails.application.config.session_store :cookie_store, key: '_your_application_name_session' # <-- rename the key

---

For Rails 4.0.x you can use the rename gem and execute the following command:

rails g rename:app_to New-Name

This will update the necessary files for you:

old/ (master)  › rails g rename:app_to new
Search and replace module in to...
    gsub  config.ru
    gsub  Gemfile
    gsub  Gemfile.lock
    gsub  Rakefile
    gsub  README.md
    gsub  config/application.rb
    gsub  config/boot.rb
    gsub  config/environment.rb
    gsub  config/environments/development.rb
    gsub  config/environments/production.rb
    gsub  config/environments/test.rb
    gsub  config/initializers/backtrace_silencers.rb
    gsub  config/initializers/filter_parameter_logging.rb
    gsub  config/initializers/inflections.rb
    gsub  config/initializers/load_class_extensions.rb
    gsub  config/initializers/mime_types.rb
    gsub  config/initializers/secret_token.rb
    gsub  config/initializers/session_store.rb
    gsub  config/initializers/update.rb
    gsub  config/initializers/wrap_parameters.rb
    gsub  config/routes.rb
    gsub  config/initializers/session_store.rb
Renaming references...
Renaming directory...Done!
New application path is '/Users/username/code/new'