Shoulda 2.0

Lots of shoulda news to report. The 2.0.x gem has been released, which includes bug fixes, new features, and deprecations.

Rails 2.1+ install

The gem is being hosted at github.com/thoughtbot/shoulda.

Specify the gem dependency in your config/environment.rb file:

Rails::Initializer.run do |config|
  config.gem 'thoughtbot-shoulda', :lib => 'shoulda/rails', :source => "http://gems.github.com"
end

Then:

rake gems:install
rake gems:unpack

Now 100% gem

Why gems?

  • Ruby comes with a packaging system. No need for another, especially with the gem support in Rails 2.1.
  • It’s nice to scan the vendor/gems listing and see version numbers.
  • github has excellent gem support.
  • In shoulda’s case, it’s a project that can be used in and out of Rails. It’s a pain to have both a plugin and a gem.

Ryan McGeary and Josh Nichols did the bulk of this conversion and related refactoring. They deserve extra acclaim because they’ve made it easier for everyone to contribute to shoulda.

Improvements to current macros

should_assign_to now takes an :equals option. This is now the preferred way to use should_assign_to for edit, show, update, and destroy actions because it is a better test when you explicitly compare assigns(:user) to an expected object.

should_assign_to :user, :equals => "@user"

should_assign_to also now takes a :class option. This is especially good for new actions.

should_assign_to :user, :class => User

should_have_one now supports the :dependent option.

should_have_one :address, :dependent => :destroy

ActiveRecord::Errors.default_error_messages is used instead of home-brewed regexes for all Active Record macros.

New Macros

should_change creates a test asserting a change between the return value of an expression that is run before and after the current setup block is run. This is similar to Active Support’s assert_difference assertion, but supports more than just numeric values.

context "Creating a post"
  setup { Post.create }
  should_change "Post.count", :by => 1
end

# :from and :to examples
should_change "Post.count", :from => 0, :to => 1
should_change "@post.title", :from => "old", :to => "new"

should_not_change creates a test asserting no change between the return value of an expression that is run before and after the current setup block is run.

context "Updating a post"
  setup { @post.update_attributes(:title => "new") }
  should_not_change "Post.count"
end

should_filter_params creates a test asserting that filter_parameter_logging is set for the specified keys should_filter_params :password, :ssn

should_render_with_layout creates a test asserting that the controller rendered with the given layout.

should_render_with_layout # defaults to application
should_render_with_layout 'special'
should_render_without_layout

should_route creates a routing test. It tries to use the given HTTP method on the given path, and asserts that it routes to the given options.

should_route :get, "/posts", :controller => :posts, :action => :index
should_route :delete, "/posts/1", :action => :destroy, :id => 1
should_route :get, "/users/1/posts/1",
  :action => :show, :id => 1, :user_id => 1

should_respond_with_content_type creates a test asserting that the response content type was content_type.

should_respond_with_content_type 'application/rss+xml'
should_respond_with_content_type :rss
should_respond_with_content_type /rss/

should_return_from_session creates a test asserting that a value returned from the session is correct. The given string is evaled to produce the resulting redirect path. All of the instance variables set by the controller are available to the evaled string.

should_return_from_session :user_id, "@user.id"

Before statements

Before statements are should statements that run before the current context’s setup. These are especially useful when setting expectations.

class UserControllerTest < Test::Unit::TestCase
  context "the index action" do
    setup do
      @users = [Factory(:user)]
      User.stubs(:find).returns(@users)
    end

    context "on GET" do
      setup { get :index }

      should_respond_with :success

      # runs before "get :index"
      before_should "find all users" do
        User.expects(:find).with(:all).returns(@users)
      end
    end
  end
end

Automatically load custom macros

Writing custom macros is a common practice for The Modern Shoulda Developer. For example, shouldhaveattached_file used to be a handy custom macro to have around when you’re using Paperclip.

There were a few problems with that, however. Where should that macro go? RAILS_ROOT/test/test_helper.rb? Why do we have the same macro in multiple apps for the same plugin?

Enter the new shoulda_macros directory. Shoulda will automatically load custom macros she finds in:

RAILS_ROOT/test/shoulda_macros
RAILS_ROOT/vendor/gems/#{gem_name}/shoulda_macros
RAILS_ROOT/vendor/plugins/#{plugin_name}/shoulda_macros

Now, every Paperclip user can use the latest shouldhaveattached_file because it is where it belongs.

should_be_restful is being deprecated

should_be_restful will be removed in a future release. It is currently in a grace period where you’ll see a warning during your test runs. It will be added to the new woulda gem if you care to keep using it. Its problems:

  • It dissuades the programmer from good TDD practice. It’s working at too high level of abstraction and encourages the programmer to take too many big steps.
  • It is an attempt to be like Rails scaffolding, which is a good way to learn REST, but the syntax is so cryptic it doesn’t accomplish that goal.
  • It’s near impossible to find the line in your test file that is actually failing or erroring.
  • You have no idea how many tests it generates or how they’re implemented, which lulls the programmer into a false sense of security.

Removed

  • load_all_fixtures (use fixtures :all instead)
  • shoulda.conf and color support (use the redgreen gem instead)

Credit

Ryan McGeary, Matt Jankowski, Mike Boone, Tammer Saleh, Josh Nichols, Joe Ferris, Keith Morrison, Dan Croak.

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