Use Rack::Builder.parse_file to test your config.ru

gistfile2.txt

test_rack_config.rb

require 'minitest/autorun'
require 'minitest/spec'
require 'rack/test'

describe "config.ru" do
  include Rack::Test::Methods

  def app
    # parse_file returns an array, but we need a rack app
    Rack::Builder.parse_file('path/to/your/config.ru').first
  end

  it "should have redirects" do
    get "/old"
    follow_redirects!
    last_request.path.must_equal "/new"
  end
end