Rails%203%20In%20Action

482 CHAPTER 17 Engines
s.add_development_dependency "rspec-rails", "~> 2.5"
s.add_development_dependency "capybara"
You can run bundle install to install these two gems as dependencies because you’ve
got the gemspec method call in Gemfile. Once that command is done, then you’ve got
what you need in terms of gems.
Your next move is to set up Capybara to be used with RSpec. In spec/spec_helper
.rb there’s this line:
Dir["#{File.dirname(__FILE__)}/support/**/*.rb"].each { |f| require f }
This line will require all the files with a .rb extension within the spec/support directory
or its subdirectories. You can use this to load Capybara for your tests by creating the
spec/support folder and putting a file called spec/support/capybara.rb inside of it with
this content:
require 'capybara/rails'
require 'capybara/dsl'
RSpec.configure do |c|
c.include Capybara, :example_group => {
:file_path => /\bspec\/integration\//
}
end
The capybara/rails sets up Capybara to be used for your dummy application (which
loads your engine), while the capybara/dsl gives you all the helpful Capybara methods
that you’re going to need in your tests.
The final chunk of code here includes the Capybara module within all tests that
are within the spec/integration directory. This should provide a pretty big clue as to
where your integration tests are going for your engine!
That’s all that you’ve got to do for setting up Capybara and RSpec. Let’s make a
commit for this:
git add .
git commit -m "Remove Test::Unit, replace with RSpec + Capybara"
Now why don’t we get into some real coding?
17.5 Writing your first engine feature
When they first start writing a Rails application, many people will attempt to create a
forum system. 17 This is a great place to start, as a lot of people have used forum systems
18 and therefore they understand the basic concepts of how they work.
Generally, on the home page there’s a list of forums that have topics inside of them
and then posts inside of those topics. Each topic and post are created by a user, and
there’s a wide gamut of conversation (and, on larger forums, a great deal of trolling)
that goes on in them.
17 One of the authors attempted such a project and it grew into rboard: http://github.com/radar/rboard.
18 Such as PHPbb and VBulletin.