test_helper.rb

# Allows you to use the :session key in your tests
# (when using rack-test).
#
#   get "/", {}, :session => {:user => 1}
#
class Test::Unit::TestCase
  include Rack::Test::Methods

  def app
    Sinatra::Application
  end

  def rack_test_session
    @_rack_test_session ||= Session.new(app)
  end

  class Session < Rack::Test::Session
    def env_for(path, env)
      if session = env.delete(:session)
        env.merge!(:cookie => "#{Rack::Utils.escape('rack.session')}=#{[Marshal.dump(session)].pack("m*")}")
      end

      super(path, env)
    end
  end
end