gistfile1.rb

# Using standard lib methods 
  assert redirect? "not redirected"
  
  query_hash = CGI.parse(URI.parse(redirected_to).query)
  assert query_hash.fetch(query_param, false), "'#{query_param}' param is not set, or has an empty value"
  
  url = URI.parse(url)
  params = CGI.parse(url.query || '')
  params[query_param] = query_hash[query_param]
  url.query = params.map{|k,v| "#{CGI::escape(k)}=#{CGI::escape(v.first)}"}.join('&')

  assert url.to_s == redirected_to, "redirection URL is incorrect"

# Or, a slightly shitty regex

  assert redirect?, "not redirected"
  assert_false "No token in query" unless redirected_to.gsub!(/(?:&|\?)token=.*/, '')
  assert_equal redirected_to, url