minimalist_factories.rb

require "ffaker"

class ActiveRecord::Base
  def self.define_factory(name=:factory, &block)
    scope name, lambda { |overrides={}|
      attributes = instance_eval(&block).merge(overrides)
      where(attributes)
    }
  end
end

class User < ActiveRecord::Base
  define_factory {{
    :name  => Faker::Name.name,
    :email => Faker::Internet.email
  }}
end

class UserTest < ActiveSupport::TestCase
  test "name factory" do
    user = User.factory(:name => "John Doe").new
    assert_equal "John Doe", user.name
  end
end

Nice!