Mongoid Criteria .to_a redundancy

mongoid_criteria_array_bug.rb

### make sure the mongoid.yml is a file in the same directory:
# test:
#   sessions:
#     default:
#       database: db
#       hosts:
#         - localhost:27017

### run with:
# export MONGOID_ENV=test; ruby mongoid_criteria_array_bug.rb

require 'rubygems'
require 'mongoid'
require 'minitest/autorun'

Mongoid.load!('mongoid.yml')

class Person
  include Mongoid::Document
  has_many :pets
end

class Pet
  include Mongoid::Document
  belongs_to :person
end

describe Person do
  before do
    @person = Person.create
    5.times { Pet.create(person: @person) }
  end

  describe "when asked about it's pets" do
    describe "after finding a pet" do
      it "does not return redundant pets" do
        @person.pets.find(@person.pets.first.id)
        @person.pets.count.must_equal(@person.pets.to_a.size)
      end
    end
  end
end