snippet.rb

### NOTE!! Store this file in the 
#   
#   github.com/datamapper/dm-more/tree/next  # Next branch
#   |
#   |--> dm-is-list/spec/integration



require 'pathname'
require Pathname(__FILE__).dirname.expand_path.parent + 'spec_helper'

require Pathname(__FILE__).dirname.expand_path.parent.parent.parent / 'dm-is-tree' / 'lib' / 'dm-is-tree' / 'is' / 'tree.rb'


if HAS_SQLITE3 || HAS_MYSQL || HAS_POSTGRES
  describe 'DataMapper::Is::List' do

    class Album 
      include DataMapper::Resource
      
      property :id, Serial
      property :parent_id, Integer,  :default => 0
      property :name, String
      
      is :list, :scope => [:parent_id] #, :order => [:position]
      is :tree, :order => [:parent_id, :position]
      
    end
    
    before :each do
      Album.auto_migrate!
      
      Album.create(:name => 'Album1')
      Album.create(:name => 'Album2')
      Album.create(:name => 'Album3')
      Album.create(:name => 'Album4')
      @album5 = Album.create(:name => 'Album5')
      
    end
    
    describe 'Strange behaviour with reference objects' do
      
      it 'this test fails with mismatch on the position of Album.get(5)' do
        DataMapper.repository(:default) do |repos|
          album5 = Album.get(5)
          album5.position.should == 5
          album5.position.should == @album5.position
          
          @album5.update(:position => 20)
          
          @album5.position.should == 20
          
          Album.all.map{ |a| [a.id, a.position] }.should == [ [1, 1], [2, 2], [3, 3], [4, 4], [5, 20] ]
        end
      end
      
      it 'this test passes because I do a reload of the temporary "album5" variable' do
        DataMapper.repository(:default) do |repos|
          album5 = Album.get(5)
          album5.position.should == 5
          album5.position.should == @album5.position
          
          @album5.update(:position => 20)
          
          @album5.position.should == 20
          
          album5.position.should == 5
          album5.reload
          
          Album.all.map{ |a| [a.id, a.position] }.should == [ [1, 1], [2, 2], [3, 3], [4, 4], [5, 20] ]
          
        end
      end
      
    end
    
  end
end