Sinatra.rb

# Application
class App < Sinatra::Base
  set :hi, "Hello"
  
  configure :test do
    set :hi, "Hello There!"
  end
end

# Registering a extention
module App
  class Hi
    def self.registered(app)
      if app.test?
        app.set :hi, "Hello There!"
      else
        app.set :hi, "Hello"
      end
    end
  end
end

class App < Sinatra::Base
  register App::Hi
end

# Rspec Tests

# You need to include Rack::Test::Methods so you get like be_nil etc
Spec::Runner.configure do |conf|
  conf.include Rack::Test::Methods
end

Sinatra::Base.set :environment, :test
# You can overide settings like this too
# Sinatra::Base.set :hi, "Hi There!"

describe App do
  def app
    @app ||= App
  end

  it "should be in environment test" do
    app.environment.should == :test
  end
  
  it "should say 'Hello There!'" do
    app.hi.should == "Hello There!"
  end
end