Testing Facebook interaction with Facebooker

gistfile1.rb

# DISCLAIMER: this is just a hack, not even tested.
# I use this for testing interaction with Facebook.
# Basically there are a bunch of fixture XMLs that
# represent the response from Facebook.
# Oh, make sure you do this somewhere, probably in
# a setup/before block:
# 
#   Facebooker::Session.current = Facebooker::MockSession.create
# 
# (You might need to stub session[:facebook_session] too.)

require 'digest/md5'

module Facebooker
  class MockService < Service
    def post(params)
      method = params[:method]

      params.delete(:v)
      params.delete(:method)
      params.delete(:api_key)
      params.delete(:call_id)
      params.delete(:sig)

      filename = get_fixture_name(params)

      path = get_fixture_path(method, filename)

      begin
        begin
          response = Parser.parse(method, File.read(path))
        rescue Errno::ENAMETOOLONG
          tries = 0

          md5_alternative = nil

          begin
            md5_path = get_hashed_fixture_path(method, md5_alternative || filename)
            response = Parser.parse(method, File.read(md5_path))

            if md5_alternative
              puts "It looks like you need to rename this file due to changes in Facebooker's user fields."
              $stderr.puts "git mv #{md5_path} #{get_hashed_fixture_path(method, filename)}"
            end

          rescue Errno::ENOENT => e
            fields ||= params[:fields].split(',') if params[:fields]
            tries += 1

            raise if fields.nil? || tries > Facebooker::User::FIELDS.size

            fields.delete(Facebooker::User::FIELDS[-tries].to_s)
            md5_alternative = get_fixture_name(params.merge(:fields => fields.join(',')))
            retry
          end
        end
      rescue Errno::ENOENT => e
        e.message << "\n(Non-hashed path is #{path})" if md5_path
        e.message << "\nFacebook API Reference: http://wiki.developers.facebook.com/index.php/#{method.sub(/^facebook\./, '')}#Example_Return_XML"

        raise e
      end

      response
    end

    def kind_of?(klass)
      if klass == Facebooker::Session
        true
      else
        super
      end
    end

    private
      def get_fixture_path(method, filename)
        File.join('.', 'test', 'fixtures', 'facebook', method, "#{filename}.xml")
      end

      def get_hashed_fixture_path(method, filename)
        get_fixture_path(method, Digest::MD5.hexdigest(filename))
      end

      def get_fixture_name(params)
        params.map {|*args| args.join('=') }.sort.join('&')
      end
  end

  class MockSession < Session
    def secured?
      true
    end

    def secure!
      @uid = 1
      true
    end

    def service
      @service ||= MockService.new(Facebooker.api_server_base, Facebooker.api_rest_path, @api_key)
    end
  end
end