Complex object matcher

object_match.rb

module Kernel
  def object_match?(a, b, cmp_key = 'guid')
    cmp = lambda {|x,y| (x[cmp_key] <=> y[cmp_key]).to_i}

    if a.kind_of? Hash
      a.each do |key, value|
        return false unless object_match?(value, b[key], cmp_key)
      end
    elsif a.kind_of? Array
      a.sort!(&cmp)
      b.sort!(&cmp)
      a.each_index do |index|
        return false unless object_match?(a[index], b[index], cmp_key)
      end
    else
      a == b
    end
  end
end

object_match_spec.rb

require 'spec_helper'

require 'object_match'

describe Kernel do

  describe "synthetic test" do
    let(:a) { {:x => [{:a => 1}, {:a => 2}], :y => [{:a => 3}, {:a => 4}] } }
    let(:b) { {:y => [{:a => 4}, {:a => 3}], :x => [{:a => 2}, {:a => 1}] } }
    let(:c) { {:x => [{:a => 6}, {:a => 7}], :y => [{:a => 8}, {:a => 9}] } }

    specify "should match" do
      object_match?(a, b, 'a'.to_sym).should be_true
    end

    specify "should not match" do
      object_match?(a, c, 'a'.to_sym).should be_false
    end
  end

  describe "real life test" do
    let(:a) { {"highlights"=>[{"guid"=>"444", "updated_at"=>1303761600, "id"=>"4", "verse_id"=>4, "word_id"=>4, "style"=>444}, {"guid"=>"222", "deleted"=>true}, {"guid"=>"111", "deleted"=>true}]} }
    let(:b) { {"highlights"=>[{"guid"=>"111", "deleted"=>true}, {"guid"=>"444", "updated_at"=>1303761600, "id"=>"4", "verse_id"=>4, "word_id"=>4, "style"=>444}, {"guid"=>"222", "deleted"=>true}]} }

    specify "should match" do
      object_match?(a, b, 'guid').should be_true
    end
  end
end