How do I create a command line rails generator gem?

Question

I know how to create a rails generator gem which is called like:

rails g my_generator command

And I know how to create a thor gem which can be called like:

my_generator command

But I don't know how to create a rails generator that can be called using an executable. I have tried by creating a lib/my_generator/cli.rb file like:

require 'thor'

module Mang
  class Cli < Thor
    include ::Rails::Generators::Base

    desc "install_gem", "install a gem"
    def install_gem
      gem 'thor', "0.18.1"
    end

  end
end

But I get the following error despite having added Rails as a dependency in my gemspec.

uninitialized constant Rails (NameError)

Answer 1

The fix was just a matter of including the rails/generators/actions module.

require 'thor'
require 'rails/generators'
require 'rails/generators/actions'

module Mang
  class Cli < Thor
    include Thor::Actions
    include Rails::Generators::Actions

    desc "install_gem", "install a gem"
    def install_gem
      gem 'thor', "0.18.1"
    end

  end
end