From: "Molitor, Stephen L" <Stephen.L.Molitor@...>
Date: 2006-05-25T01:12:23+09:00
Subject: Re: Overriding Time.now

> I believe that you can redefine Time.now in the scope where you need
> it without interfering with Test::Unit

There's only one instance of the Time class object, and any changes you make to it are in effect 'global'.  At least in Ruby 1.8.  I understand there's some talk of adding namespaces or something to be able to make modifications and extensions to classes only apply in a certain scope in Ruby 2.0.  

Steve

-----Original Message-----
From: Robert Dober [mailto:robert.dober@gmail.com] 
Sent: Wednesday, May 24, 2006 10:19 AM
To: ruby-talk ML
Subject: Re: Overriding Time.now

On 5/24/06, Molitor, Stephen L <Stephen.L.Molitor@erac.com> wrote:
>
> One caution:  I did what Robert suggested a while back.  It works 
> perfectly, but does wreak havoc with Test::Unit and rake test times 
> reporting.  Tests can appear to finish before they've started, etc.  I 
> ended up creating a CurrentTime class:
>
> class CurrentTime
>   @@now = nil
>
>   def now
>     @@now || Time.now
>   end
>
>   def now=(new_time)
>     @@now = new_time
>   end
> end
>
> I changed my code to use CurrentTime.now instead of Time.now.  
> Test::Unit, rake and friends still use Time.now, so they don't get 
> messed up.  In my unit test I mock out the time by calling 
> CurrentTime.now=.  Crude but it works.


Yup you have to change the code to be tested, not the best idea.
I guess you can avoid this by redefining now only in the class to be tested, please note I did not hang anybody (by not redefining Time.now) just gave you the rope to hang yourself (by redefining Time.now).
Now (pun intended) I believe that you can redefine Time.now in the scope where you need it without interfering with Test::Unit, well you are still administring the code you test somehow.
Neverheless that might be the cleanest approach, I would be glad to have a better one suggested though.

Cheers
Robert

Steve
>
> -----Original Message-----
> From: Robert MannI [mailto:robmnl@gmail.com]
> Sent: Wednesday, May 24, 2006 9:37 AM
> To: ruby-talk ML
> Subject: Re: Overriding Time.now
>
> Thanks alot Robert, that'll do it
>
>
>
> Rob
>
> On 5/24/06, Robert Dober <robert.dober@gmail.com> wrote:
> >
> > On 5/24/06, Robert MannI <robmnl@gmail.com> wrote:
> > >
> > > Hello!
> > >
> > > I have a unit test where I need to simulate a different system time.
> > >
> > > Hence I need Time.now to return a different time than now, say, 
> > > now
> > > + 1 month
> > >
> > > How can I do this?
> > >
> > > I tried aliasing Time now, but I don't know how to alias class
> methods.
> > >
> > > class Time
> > > alias_method 'self.original_now', 'self.now'
> > > end
> > >
> > > How can I alias this --or-- is there any better way to simulate a 
> > > different time on calling Time.now?
> > >
> > >
> > > Tips and ideas are greatly appreciated, Rob
> >
> >
> > Hi
> >
> > class Time
> >     class << self
> >         alias_method :n, :now
> >     end
> > end
> >
> > hope that helps
> > Cheers
> > Robert
> >
> >
> > --
> > Deux choses sont infinies : l'univers et la b�tise humaine ; en ce 
> > qui concerne l'univers, je n'en ai pas acquis la certitude absolue.
> >
> > - Albert Einstein
> >
> >
>
>


--
Deux choses sont infinies : l'univers et la b�tise humaine ; en ce qui concerne l'univers, je n'en ai pas acquis la certitude absolue.

- Albert Einstein