thoughtbot--shoulda-matchers/spec/support/unit/helpers/controller_builder.rb

module UnitTests
  module ControllerBuilder
    def self.configure_example_group(example_group)
      example_group.include(self)

      example_group.after do
        delete_temporary_views
        restore_original_routes
      end
    end

    def define_controller(class_name, &block)
      class_name = class_name.to_s
      class_name << 'Controller' unless class_name =~ /Controller$/
      define_class(class_name, ActionController::Base, &block)
    end

    def define_routes(&block)
      self.routes = $test_app.draw_routes(&block)
    end

    def build_fake_response(opts = {}, &block)
      action = opts[:action] || 'example'
      partial = opts[:partial] || '_partial'
      block ||= lambda { render nothing: true }
      controller_class = define_controller('Examples') do
        layout false
        define_method(action, &block)
      end
      controller_class.view_paths = [ $test_app.temp_views_directory.to_s ]

      define_routes do
        get 'examples', to: "examples##{action}"
      end

      create_view("examples/#{action}.html.erb", 'action')
      create_view("examples/#{partial}.html.erb", 'partial')

      setup_rails_controller_test(controller_class)
      self.class.render_views(true)

      get action

      controller
    end

    def setup_rails_controller_test(controller_class)
      @controller = controller_class.new
    end

    def create_view(path, contents)
      $test_app.create_temp_view(path, contents)
    end

    def controller_for_resource_with_strong_parameters(options = {}, &action_body)
      model_name = options.fetch(:model_name, 'User')
      controller_name = options.fetch(:controller_name, 'UsersController')
      collection_name = controller_name.
        to_s.sub(/Controller$/, '').underscore.
        to_sym
      action_name = options.fetch(:action, :some_action)
      routes ||= options.fetch(:routes, -> { resources collection_name })

      define_model(model_name)

      controller_class = define_controller(controller_name) do
        define_method action_name do
          if action_body
            instance_eval(&action_body)
          end

          render nothing: true
        end
      end

      setup_rails_controller_test(controller_class)

      define_routes(&routes)

      controller_class
    end

    def delete_temporary_views
      $test_app.delete_temp_views
    end

    def restore_original_routes
      Rails.application.reload_routes!
    end
  end
end