require 'bundler/inline'
require 'tempfile'

gemfile do
  source 'https://rubygems.org'
  gem 'mongoid', '7.1.4'
end

Tempfile.open(%w(config.yml)) do |f|
  f.write(<<~YAML)
development:
  clients:
    default:
      uri: mongodb://mongo/test
  YAML
  f.flush

  Mongoid.load!(f.path, 'development')
end

class Parent
  include Mongoid::Document
  include Mongoid::Timestamps

  has_one :child, dependent: :destroy
end

class Child
  include Mongoid::Document
  include Mongoid::Timestamps

  belongs_to :parent
end

parent = Parent.create
child = Child.create(parent: parent)
p Child.find(child.id) #=> returns the child

parent.child = child
p Child.find(child.id) #=> raises Mongoid::Errors::DocumentNotFound