{"id":1196,"date":"2012-01-07T12:45:36","date_gmt":"2012-01-07T10:45:36","guid":{"rendered":"http:\/\/blog.railsware.com\/?p=1196"},"modified":"2021-08-13T11:39:37","modified_gmt":"2021-08-13T08:39:37","slug":"testing-gem-integration-with-multiple-ruby-frameworks","status":"publish","type":"post","link":"https:\/\/railsware.com\/blog\/testing-gem-integration-with-multiple-ruby-frameworks\/","title":{"rendered":"Testing gem integration with multiple ruby frameworks"},"content":{"rendered":"\n

Preface<\/h2>\n\n\n\n

When you develop some cool gem that should work in different ruby frameworks<\/a>
you definitely should write acceptance tests.<\/p>\n\n\n\n

Nowadays it’s pretty easy to do with RSpec+Capybara.<\/p>\n\n\n\n

Your goal<\/h2>\n\n\n\n

Assume you develop MyRackMiddleware gem that should work in Sinatra and Rails application.<\/p>\n\n\n\n

Your actions<\/h2>\n\n\n\n

Create gem layout<\/h3>\n\n\n\n

To create layout use well-known bundle gem<\/em> command:<\/p>\n\n\n\n

$ bundle gem my_rack_middleware\n<\/pre>\n\n\n\n

It’s generate something like:<\/p>\n\n\n\n\n\n\n\n
\u251c\u2500\u2500 lib\n\u2502   \u251c\u2500\u2500 my_rack_middleware\n\u2502   \u2502   \u2514\u2500\u2500 version.rb\n\u2502   \u2514\u2500\u2500 my_rack_middleware.rb\n\u251c\u2500\u2500 Gemfile\n\u251c\u2500\u2500 my_rack_middleware.gemspec\n\u2514\u2500\u2500 Rakefile\n<\/pre>\n\n\n\n
Add to Gemfile<\/em> :<\/p>\n\n\n\n
source \"http:\/\/rubygems.org\"\n\ngemspec\n\ngem 'rspec'\ngem 'capybara'\n\ngem 'sinatra'\ngem 'rails'\n<\/pre>\n\n\n\n
Now start use BDD :) Before start implementation we need two sample applications.
Let’s put they into apps<\/em> directory.<\/p>\n\n\n\n
Creating Sinatra test application<\/h3>\n\n\n\n
Thus Sinatra is simple framework it’s trivial to create test application:<\/p>\n\n\n\n
$ cat apps\/test_sinatra_app.rb \n<\/pre>\n\n\n\n
require 'sinatra'\nclass TestSinatraApp < Sinatra::Base\n  enable :sessions\n\n  get '\/login' do\n    body \"Please log in\"\n  end\n\n  post '\/login' do\n    session[:user_email] = params[:user_email]\n    redirect to('\/profile')\n  end\n\n  get '\/profile' do\n    if user_email = session[:user_email]\n      body \"Welcome, #{user_email}!\"\n    else\n      redirect to('\/login')\n    end\n  end\nend\n<\/pre>\n\n\n\n
Creating Rails3 test application<\/h3>\n\n\n\n
When you think that with rails it will be hard then your are wrong :)
Thanks to rails3 design its also rather simple! Let’s see:<\/p>\n\n\n\n
$ cat apps\/test_rails_app.rb \n<\/pre>\n\n\n\n
require 'rails'\nrequire 'action_controller\/railtie'\n\nmodule TestRailsApp\n  class Application < Rails::Application config.secret_token = '572c86f5ede338bd8aba8dae0fd3a326aabababc98d1e6ce34b9f5' routes.draw do get '\/login' => 'test_rails_app\/sessions#new'\n      post '\/login'   => 'test_rails_app\/sessions#create'\n      get  '\/profile' => 'test_rails_app\/profiles#show'\n    end\n  end\n\n  class SessionsController < ActionController::Base def new render :text => \"Please log in\"\n    end\n\n    def create\n      session[:user_email] = params[:user_email]\n      redirect_to '\/profile'\n    end\n  end\n\n  class ProfilesController < ActionController::Base def show if user_email = session[:user_email] render :text => \"Welcome, #{user_email}!\"\n      else\n        redirect_to '\/login' \n      end\n    end\n  end\nend\n<\/pre>\n\n\n\n
So you have whole rails application<\/em> in one file. Nice! :)<\/p>\n\n\n\n
Write integration tests<\/h3>\n\n\n\n
Now is most interesting part of this article.
Capybara gem itself has rspec helpers that allows you to write rspec examples
in way of acceptance testing (aka feature<\/em> and scenario<\/em>).<\/p>\n\n\n\n
Actually internally feature<\/em> is just alias to ExampleGroup (describe) and scenario<\/em> is alias to Example (it).
But this syntax follows you to think different.<\/p>\n\n\n\n
Put in spec\/spec_helper.rb<\/em><\/p>\n\n\n\n
require 'capybara\/rspec'\n\nrequire 'rack_session_access'\nrequire 'rack_session_access\/capybara'\n\n# load test applications\nDir[File.expand_path('..\/..\/apps\/*.rb', __FILE__)].each do |f|\n  require f\nend\n\n# configure sinatra application to use MyRackMiddleware\nTestSinatraApp.configure do |app|\n  app.use MyRackMiddleware\nend\n\n# configure rails application to use MyRackMiddleware\nTestRailsApp::Application.configure do |app|\n  app.middleware.use MyRackMiddleware\nend\n<\/pre>\n\n\n\n
Write acceptance spec for example in spec\/middleware_spec.rb<\/em> :
Follow DRY principle and use shared_examples<\/em>!<\/p>\n\n\n\n
require 'spec_helper'\n\nshared_examples \"common scenarios\" do\n  scenario \"test application itself\" do\n    page.visit \"\/login\"\n    page.should have_content(\"Please log in\")\n\n    page.visit \"\/profile\"\n    page.should have_content(\"Please log in\")\n  end\n\n  scenario \"MyRackMiddleware related scenario ...\" do\n    ...\n  end\nend\n\nfeature \"MyRackMiddleware\", %q(\n  As ROLE\n  I want FEATURE\n  So I have BENEFIT\n) do\n\n  context \"with Sinatra application\" do\n    background do\n      Capybara.app = TestSinatraApp\n    end\n\n    include_examples \"common scenarios\"\n  end\n\n  context \"with Rails application\" do\n    background do\n      Capybara.app = TestRailsApp::Application\n    end\n\n    include_examples \"common scenarios\"\n  end\nend\n\n<\/pre>\n\n\n\n
Run tests<\/h3>\n\n\n\n
Before implementation run specs<\/p>\n\n\n\n
$ bundle exec rspec -fs -c spec\/middleware_spec.rb\n<\/pre>\n\n\n\n
Now you may add scenarios that cover your MyRackMiddleware influence on applications and start your middleware implementation!<\/p>\n\n\n\n
Conclusion<\/h3>\n\n\n\n
We hope this article will help you to write better tests for your gems.<\/p>\n\n\n\n
References<\/h2>\n\n\n\n