Testing non-persistent fields on persisted identity-mapped entity instances in JRuby and Sequel through jdbc-postgres

non_persistent_test.rb

#! /usr/bin/env jruby

require 'rubygems'
require 'sequel'

DB = Sequel.sqlite

DB.create_table? :test do
  primary_key :id
  foreign_key :parent_id, :test, :on_delete => :set_null
  String  :name
  String  :object_type, :null => false
  index :name
end

Sequel::Model.plugin :identity_map

class Test < Sequel::Model(:test)
  plugin :rcte_tree
  plugin :single_table_inheritance, :object_type

  def non_persistent_stuff
    @non_persistent_stuff ||= []
  end

  def to_s
    "#{name} <object_id:#{object_id},entity_id:#{id}>"
  end
end

a = Test.find_or_create(:name => 'A')
b = nil
c = nil

t0 = Thread.new do
  b = Test.find_or_create(:name => 'B')
  c = Test.find_or_create(:name => 'C')

  a.add_child b

  puts "a.children.include? b # => #{a.children.include? b}"
  b.non_persistent_stuff << c
  puts ""
  puts "b (should be 'B') # => #{b}"
  puts "b.non_persistent_stuff # => [#{b.non_persistent_stuff}]"
  puts "b.non_persistent_stuff.include? c # => #{b.non_persistent_stuff.include? c}"
end

t0.join

puts ""

t1 = Thread.new do
  Test.with_identity_map do
    x = Test.find(:name => 'A')
    b = Test.find(:name => 'B')
    z = Test.find(:name => 'C')
    b.non_persistent_stuff << c
    y = x.children.first
    puts "x (should be 'A') # => #{x}"
    puts "z (should be 'C') # => #{z}"
    puts "x.children.include? b # => #{a.children.include? b}"
    puts ""
    puts "b (should be 'B') # => #{b}"
    puts "y (should be 'B') # => #{y}"
    puts ""
    puts "b == y (should be true) # => #{b == y}"
    puts "b.object_id == y.object_id (shouldn't this be true? perhaps I don't understand what an identity map does) # => #{b.object_id == y.object_id}"
    puts ""
    puts "y.non_persistent_stuff # => [#{y.non_persistent_stuff}]"
    puts "y.non_persistent_stuff.include? z # => #{y.non_persistent_stuff.include? z}"
  end
end

t1.join

Sequel::Model.db.drop_table :test if Sequel::Model.db.table_exists? :test