Solving a challenge

challenge.rb

require 'uri'
require 'net/http'
require 'json'
require 'cgi'

module Challenge
  # Evaluate the uri, parse the payload and return updated uri or nil if
  # payload does not have 'follow' key
  def self.check_uri(uri)
    response = Net::HTTP.get_response(uri)
    payload = JSON.parse(response.body)
    follow = payload.is_a?(Hash) && payload.key?('follow') ? payload['follow'] : nil
    if follow.nil?
      message = payload.is_a?(Hash) && payload.key?('message') ? payload['message'] : 'Empty output'
      puts message
      return nil
    end
    puts "Follow: #{follow}"

    params = CGI.parse(URI.parse(follow).query)
    uri.query = URI.encode_www_form(params)
    puts "URI: #{uri}"
    uri
  end

  # Check the uri has 'follow' key and continue the loop if not return nil
  def self.solve(url)
    uri = URI(url)
    loop do
      uri = check_uri(uri)
      break if uri.nil?
    end
  end
end

Challenge.solve('https://www.letsrevolutionizetesting.com/challenge.json')