trying to simulate https://github.com/mongoid/mongoid/issues/2985#issuecomment-22911190

thread_spec.rb

# encoding: utf-8
require "spec_helper"

class Person
  include Mongoid::Document

  has_many :pets

  field :name
end

class Pet
  include Mongoid::Document
  
  belongs_to :person

  field :species
end

describe "ThreadSpec" do

  context 'with two collections and many threads' do
    let(:pet)   { Pet.new }
    let(:person) { Person.new }

    before do
      threads = (0...50).map do
        Thread.new do
          Pet.store_in collection: 'bands'
          Person.store_in collection: 'artists'
        end
      end

      threads.map(&:join)
    end

    after do
      Pet.storage_options = nil
      Person.storage_options = nil
    end

    it 'sets the right collection for Band' do
      expect(Pet.collection.name).to eq('bands')
    end

    it 'sets the right collection for Artist' do
      expect(Person.collection.name).to eq('artists')
    end
  end
end

running on:

Arthurs-MacBook-Pro:echo arthurnn$ ruby -v
jruby 1.7.4 (1.9.3p392) 2013-05-16 2390d3b on Java HotSpot(TM) 64-Bit Server VM 1.7.0_17-b02 [darwin-x86_64]

gems

  * carrierwave-mongoid (0.3.0)
  * mongoid (3.1.4)
  * mongoid-grid_fs (1.7.0)
  * moped (1.5.1)