fab-manager/config/initializers/active_record_base.rb

ActiveRecord::Base.class_eval do
  def dump_fixture
    fixture_file = "#{Rails.root}/test/fixtures/#{self.class.table_name}.yml"
    File.open(fixture_file, "a") do |f|
      f.puts({ "#{self.class.table_name.singularize}_#{id}" => attributes }.
        to_yaml.sub!(/---\s?/, "\n"))
    end
  end

  def self.dump_fixtures
    fixture_file = "#{Rails.root}/test/fixtures/#{self.table_name}.yml"
    mode = (File.exists?(fixture_file) ? 'a' : 'w')
    File.open(fixture_file, mode) do |f|

      if self.attribute_names.include?("id")
        self.all.each do |instance|
          f.puts({ "#{self.table_name.singularize}_#{instance.id}" => instance.attributes }.to_yaml.sub!(/---\s?/, "\n"))
        end
      else
        self.all.each_with_index do |instance, i|
          f.puts({ "#{self.table_name.singularize}_#{i}" => instance.attributes }.to_yaml.sub!(/---\s?/, "\n"))
        end
      end
    end
  end
end