Simple Null Object Pattern

NullObject

class NullObject
  # You can instantiate a new NullObject with arbitrary methods by calling
  # NullObject.new({method1: "outcome1"})
  # That will apply the method to the object
  def initialize(methods={})
    methods.each_pair do |k,v|
      define_singleton_method k do |*params|
        v
      end
    end
  end
end

Say you need something that quacks like current_user.has_a_pony.
You can just do:

  def current_user
    User.find(id) || NullObject.new(:has_a_pony, true)
  end