require 'helper' class NameApp include Newark def upcase(str) str.upcase end get '/upcaser' do upcase(params[:name]) end end class TestApp < Minitest::Unit::TestCase include Rack::Test::Methods def app NameApp.new end def test_instance_method_access get '/upcaser', { name: 'mike' } assert last_response.ok? assert_equal 'MIKE', last_response.body end end