Question

I’m working with the UUIDTools gem in Rails 3 and running into some problems. It seems to work fine in practice:

> item = Item.create
 => #<Item uuid: "e9d00043-9200-4497-a55c-509c5de3dd88", created_at: "2012-01-09 01:56:49", updated_at: "2012-01-09 01:56:49">
> item.id
 => "e9d00043-9200-4497-a55c-509c5de3dd88"

But then in my specs it tells a different story:

require 'spec_helper'
describe Item do
  it 'should assign an id' do
    item = Item.create
    puts "item id: #{item.id}"
  end
end

Running this spec shows:

item id: 5
.

Finished in 2.21 seconds
1 example, 0 failures

Where’s my guid? There doesn’t seem to be any pattern to what id is assigned, I’ve run this a bunch of times and seen it go anywhere from 0 to up in the thousands.

Here is my migration:

class CreateItems < ActiveRecord::Migration
  def change
    create_table :items, :id => false do |t|
      t.string :uuid, :null => false, :primary => true

      t.timestamps
    end

    add_index :items, :uuid, :unique => true
  end
end

My model:

require 'uuid_helper'

class Item < ActiveRecord::Base
  include UUIDHelper
end

And my uuid_helper:

module UUIDHelper
  def self.included(base)
    base.class_eval do
      set_primary_key :uuid
      attr_readonly :uuid
      before_create :set_uuid

      private

      def set_uuid
        self.uuid = UUIDTools::UUID.random_create.to_s
      end
    end
  end
end

Putting some debugger logic into set_uuid I’ve discovered that it’s doing to_i on the uuid at some point. Any suggestions?

Update This seems to be a bug in the Rails test environment. When I run RAILS_ENV=test rails console I get the same behavior as in the specs–the guids are chopped off.

Answer 1

Alright, the answer was to upgrade to Rails 3.1.3 from 3.1.1.