From: Joel VanderWerf <vjoel@...>
Date: 2002-08-08T13:53:08+09:00
Subject: Re: how do i mock the presence / absence of a constant w/out getting warnings?

Patrick May wrote:
> I need to write tests for some behavior that needs to check a
> constant:
> 
> if (MOD_RUBY)
>     .... do stuff
> else
>     .... do something else
> end
> 
> I can do it by having this sort of thing:
> 
> MOD_RUBY = true
> 
> and
> 
> MOD_RUBY = false
> 
> but I don't want to get the ruby warnings.  What's another way for me
> to mock this constant?

Not sure I understand the problem, but if you're trying to redefine a 
constant in a way that won't generate warnings, how about using modules?

   module M1; K = 1; end
   module M2; K = 2; end
   # etc., for as many times as you need to change K

   include M1   # now K == 1
   include M2   # now K == 2

But repeating 'include M1' doesn't go back to K == 1. Ruby checks to see 
if the module has already been included.

If you need to be able to change the constant more dynamically, you can 
do something like:

   m = Module.new
   m.const_set(:K, variable)
   include m