require 'rubygems'
require 'mongoid'
require 'rspec'

Mongoid.config.database = Mongo::Connection.new.db("test")

describe "Associations" do
  before do
    class User
      include Mongoid::Document
      field :name, :type => String
    end


    class Person
      include Mongoid::Document

      has_and_belongs_to_many :users
    end
  end

  let!(:user) { User.create!(:name => "rafael") }
  let!(:person) { Person.create!(:users => [user]) }

  after do
    User.destroy_all
    Person.destroy_all
  end

  context "setting to empty array" do
    it "doesn't remove the User" do
      expect { person.users = [] }.to_not change(User, :count)
    end
  end

  context "setting to nil" do
    it "doesn't remove the User" do
      expect { person.users = nil }.to_not change(User, :count)
    end
  end
end

Failures:

  1) Associations setting to empty array doesn't remove the User
     Failure/Error: expect { person.users = [] }.to_not change(User, :count)
       count should not have changed, but did change from 1 to 0
     # ./mongoid-test.rb:32

  2) Associations setting to nil doesn't remove the User
     Failure/Error: expect { person.users = nil }.to_not change(User, :count)
       count should not have changed, but did change from 1 to 0
     # ./mongoid-test.rb:38