stubby_knuckles.rb

require 'rubygems'
require 'active_support'
require 'active_model'

class Stub
  def self.generate(name, *attrs)
    Object::const_set(name.intern, Class::new do
      include ActiveModel::Serialization
      include ActiveModel::Validations
      attr_accessor *attrs
      validates_presence_of *attrs
    end
    )
    Object::const_get(name).class_eval do
      def initialize(*attrs)
        self.send(:attributes=, attrs.extract_options!)
      end
    
      def attributes=(attrs)
        attrs.each{|k,v| self.send("#{k}=", v) }
      end
    end
  end
end
  
Stub.generate('Login', :username, :password)

l = Login.new(:username => 'bob')
l.valid?
puts l.errors.inspect