module GeneratorSpecHelpers
  TEMPLATE_PATH = File.expand_path("../../app_templates", __FILE__)

  def provide_existing_routes_file
    copy_to_generator_root("config", "routes.rb")
  end

  def provide_existing_application_controller
    copy_to_generator_root("app/controllers", "application_controller.rb")
  end

  def provide_existing_user_class
    copy_to_generator_root("app/models", "user.rb")
    allow(File).to receive(:exist?).and_call_original
    allow(File).to receive(:exist?).with("app/models/user.rb").and_return(true)
  end

  def provide_existing_class(class_name)
    copy_to_generator_root("app/models", "#{class_name}.rb")
    allow(File).to receive(:exist?).and_call_original
    allow(File).to receive(:exist?).with("app/models/#{class_name}.rb").and_return(true)
  end

  private

  def copy_to_generator_root(destination, template)
    template_file = File.join(TEMPLATE_PATH, destination, template)
    destination = File.join(destination_root, destination)

    FileUtils.mkdir_p(destination)
    FileUtils.cp(template_file, destination)
  end
end

RSpec.configure do |config|
  config.include GeneratorSpecHelpers

  config.before(:example, :generator) do
    destination File.expand_path("../../tmp", __FILE__)
    prepare_destination
  end
end