From: Gennady <gfb@...>
Date: 2004-05-08T01:09:53+09:00
Subject: Re: test unit & singleton

That's why you want to avoid singletons as much as possible when it 
comes to unit testing.

In cases I do need singletons, I usually end up with a regular class 
that can be unit tested, and a separate singleton class that simply 
delegates all calls to my actual class. Or something similar.

Gennady.

Guillaume Marcais wrote:

> How do you get a fresh copy of a singleton between 2 unit test? It
> somewhat breaks the principle of a singleton object as I would like to
> get a second brand new instance of the object.
> 
> Example (pseudo-code):
> 
> require 'singleton'
> 
> class MyObject
>   include Singleton
> 
>   # ... Bunch of good stuff
> end
> 
> if $0 == __FILE__
>   require 'test/unit'
> 
>   class MyObject_Test
>     def test_functionality_1
>       o = MyObject.instance
>       # ... Tests on o, which changes the internal state of o ...
>     end
> 
>     def test_functionality_2
>       o = MyObject.instance # This instance is polluted 
>                             # by previous tests
>       # ... Tests on o
>     end
>   end
> end
> 
> How would I get rid of the instance created and polluted in test 1 to
> start anew in test 2? Should I implement a 'reset' method to clear all
> states in the singleton object?
> 
> Guillaume.
> 
> 
> 
>