Test controller mixins in isolation (http://pivotallabs.com/users/jdean/blog/articles/1370-adding-routes-for-tests-specs-with-rails-3)

gistfile1.rb

require 'spec_helper'

describe Api::V9::Authenticatable, :type => :controller do

  before do
    class EndpointsController < ActionController::Base
      include Api::V9::Authenticatable
      
      def index
        render :text => 'foo'
      end
    end
    
    @controller = EndpointsController.new
    
    Rails.application.routes.draw do
      match '/endpoint' =>'endpoints#index'
    end
  end
  
  after do
    # be sure to reload routes after the tests run, otherwise all your other controller specs will fail
    Rails.application.reload_routes!
  end
  
  it 'should a valid request' do
    get :index
  end

end

This is great! 💯