From: Robert Klemme <shortcutter@...>
Date: 2010-11-03T23:06:44+09:00
Subject: Re: Inversion of Control in Ruby by passing classes - does it make any sense?

On Wed, Nov 3, 2010 at 3:00 PM, Jeremy Bopp <jeremy@bopp.net> wrote:
> On 11/3/2010 5:20 AM, Robert Klemme wrote:
>> On Tue, Nov 2, 2010 at 9:29 PM, Jeremy Bopp <jeremy@bopp.net> wrote:
>>> What I'm about to suggest will generate warnings from Ruby and is
>>> probably not the "best" way, but you could also replace OtherClass with
>>> your MockLoggerClass with a simple assignment during your test:
>>>
>>> OtherClass = MockLoggerClass  # This generates a warning...
>>> s = SomeClass.new
>>> s.do_something(1, 2)
>>
>> This is not exactly the same as it does not allow control over the
>> created instance per instance.  You basically change global state vs.
>> Manuel's approach with local state.
>
> I agree, but I was approaching this from a minimal unit test standpoint
> rather than a generally applicable part of Manuel's design.  Would you
> say that changing the global state in this way or in the other way I
> suggested is still a problem in that case?

I cannot really tell.  Maybe, if you need different loggers in
different unit tests and mix in multi threading to make your test
suite finish faster. :-)

But I do know that global state is problematic.  I guess you can find
plenty of evidence on the web (or reason about it for yourself /
according to your own code).  It should be used with extra care.  I
try to avoid it whenever possible and that approach has served me
well.

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/