From: Avdi Grimm <Avdi_B_Grimm@...>
Date: 2005-04-14T22:39:37+09:00
Subject: Re: Mocking out a class object

"David A. Black" <dblack@wobblini.net> writes:

> You're actually dealing with two classes: MyMockClass, and
> MyMockClass's singleton class.  So you would probably want to do
> something like this:
>
>      # This is to make it look nicer (as per the
>      # pending RCR :-)
>      module Kernel
>        def singleton_class
>          class << self; self; end
>        end
>      end
>
>      my_instance = ""
>
>      MyMockClass = Class.new {
>        self::FOO = "some value"
>        singleton_class.class_eval {
>          define_method(:new) {|*| my_instance}
>        }
>      }
>
>      p MyMockClass::FOO    # "some value"
>      p MyMockClass.new     # ""


Thanks, that looks exactly like what I was looking for.  It reveals
that I don't understand Ruby metaprogramming quite as well as I
thought, though.  Would you mind explaining what singleton_instance is
doing, and how it differs from just using 'self' in the class
definition?

Thanks,

Avdi