Kansas City on Rails

I received a comment in a recent article, by someone who saw the default routes in my config/routes.rb example and suggested I remove them. Yes! This makes total sense from several angles.

Between RESTful routes and named routes, there’s no good reason not to explicitly name all of your routes. Also, you don’t get the goodness of say, “pets_path” or “pet_path(@pet)” if you just let the default routes handle PetsController for you. Finally, if you’re doing TDD (test-driven development) then why aren’t you testing your routes as well?

Route testing is easy, and the tests themselves run super fast. One app of mine has almost 600 routing assertions that run in just 2 seconds. It’s fun to watch the dots for your routing tests zoom across the screen! Let’s start by adding a test file to our system with the standard boilerplate:

# test/unit/routing_test.rb
require 'test_helper'

class RoutingTest < ActionController::TestCase

end

We’ll start with some TestUnit basics before we get into how Shoulda can make life easier. There are three assertions to learn:

def test_generates_user_index
  assert_generates '/users', :controller => 'users', :action => 'index'
end

def test_recognizes_user_index
  assert_recognizes {:controller => 'users', :action => 'index'}, '/users'
end

def test_routes_user_index
  assert_routing '/users', :controller => 'users', :action => 'index'
end

The first assertion, assert_generates, verifies that if url generators like url_for are passed this hash of controllers, actions and whatever else, the correct route (/users in this case) is generated. The next assertion, assert_recognizes, does just the opposite, ensuring that a route of /users end up calling the index action of the users controller. The third version (assert_routing) does both! It combines the two previous assertions into one, and this is what you’ll want most of the time.

Using Shoulda to DRY up your tests

Here are the above tests, in Shoulda form:

require 'test_helper'

class RoutingTest < ActiveSupport::TestCase
  context "routing users" do
    should "generate /users" do
      assert_generates '/users', :controller => 'users', :action => 'index'
    end

    should "recognize users" do
      assert_recognizes {:controller => 'users', :action => 'index'}, '/users'
    end
  
    should "generate and recognize users" do
      assert_routing '/users', :controller => 'users', :action => 'index'
    end
  end
end

While these tests are simple, they’re not very DRY. Just imagine, you’ll need to have seven of these tests *just* for the most basic RESTful route. Instead, install my shoulda routing macros:

script/plugin install git@github.com:bellmyer/shoulda_routing_macros.git

Now here’s an example routing file:

# config/routes.rb
ActionController::Routing::Routes.draw do |map|
  # a simple resource
  map.resources :chickens

  # a resource with extra actions
  map.resources :users, :collection => {:thankyou => :get}, :member => {:profile => :get}

  # nested resources
  map.resources :owners do |owners|
    owners.resources :pets
  end

  # singleton resource
  map.resource :session
  map.ltp_contact_link '/ltp/:code', :controller => 'ltp_contacts', :action => 'new'
end

And this is how easy they are to test:

# test/unit/routing_test.rb
require 'test_helper'

class RoutingTest < ActionController::TestCase
  # simple
  should_map_resources :chickens

  # with extra actions
  should_map_resources :users, :collection => {:thankyou => :get}, :member => {:profile => :get}

  # nested
  should_map_resources :owners
  should_map_nested_resources :owners, :pets

  # singleton
  should_map_resource :session
end

There’s no longer a good excuse to use default routes, or not test your routes in detail. Enjoy!

Tags: developers, macros, Rails, routes, Ruby, ruby on rails, shoulda, Testing

This entry was posted on January 27, 2010 at 8:20 pm and is filed under Rails, Ruby, Testing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.