Rails - May 2006 - Model class conditional on ENV["RAILS_ENV"] == "test"

I am trying to setup a model class that I want to inherit from 
ActveRecord when in the test mode, and not inherit when in production 
and/or development mode. The reason for this is so that I can use 
fixtures to test that the logic in the model is working correctly, but I 
don''t want the database table around during production (and normal 
development).

I would like to do this the preferred "rails" way.

I''ve tried a few solutions using mixins and also using a conditional 
expression to control the class definition, but anything I come up with 
ether doesn''t work or looks some shade of ugly. (The worst being to 
duplicatee the class and wrap each definition in conditional code).

Any ideas?

Thanks in advance,
Martin

-- 
Posted via http://www.ruby-forum.com/.

Take a look at mock objects.

They may be your good friend here.

--  
-- Tom Mornini

On May 16, 2006, at 3:51 PM, Martin Stanley wrote:
> I am trying to setup a model class that I want to inherit from
> ActveRecord when in the test mode, and not inherit when in production
> and/or development mode. The reason for this is so that I can use
> fixtures to test that the logic in the model is working correctly,  
> but I
> don''t want the database table around during production (and normal
> development).
>
> I would like to do this the preferred "rails" way.
>
> I''ve tried a few solutions using mixins and also using a
conditional
> expression to control the class definition, but anything I come up  
> with
> ether doesn''t work or looks some shade of ugly. (The worst being
to
> duplicatee the class and wrap each definition in conditional code).
>
> Any ideas?
>
> Thanks in advance,
> Martin
>
> -- 
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails

Tom Mornini wrote:
> Take a look at mock objects.
> 
> They may be your good friend here.
> 
> --
> -- Tom Mornini
Thanks for your response, Tom. I''m not sure how mock objects will help 
me.

I had a look at mock objects in AWDR; the example they show helps if one 
needs to redefine specific methods in a class. My problem is that I want 
my test class to inherit from AR and my production and development class 
to not inherit from AR. I could replace the prod/dev class with a mock 
class that replaces the entire class (including the inheritance) - if 
Ruby supports this - but this would not be DRY since both classes would 
be identical except for the fact that one inherits from AR.

Can you (or anyone) shed any light on this?

Thanks,
Martin

-- 
Posted via http://www.ruby-forum.com/.

Tom Mornini wrote:
> Take a look at mock objects.
> 
> They may be your good friend here.
> 
> --
> -- Tom Mornini
Thanks for your response, Tom. I''m not sure how mock objects will help 
me.

I had a look at mock objects in AWDR; the example they show helps if one 
needs to redefine specific methods in a class. My problem is that I want 
my test class to inherit from AR and my production and development class 
to not inherit from AR. I could replace the prod/dev class with a mock 
class that replaces the entire class (including the inheritance) - if 
Ruby supports this - but this would not be DRY since both classes would 
be identical except for the fact that one inherits from AR. Perhaps I am 
missing something?

Can you (or anyone) shed any light on this?

Thanks,
Martin

-- 
Posted via http://www.ruby-forum.com/.

Martin Stanley wrote:
> Tom Mornini wrote:
>> Take a look at mock objects.
>> 
>> They may be your good friend here.
>> 
>> --
>> -- Tom Mornini
> 
> Thanks for your response, Tom. I''m not sure how mock objects will
help
> me.
> 
> I had a look at mock objects in AWDR; the example they show helps if one 
> needs to redefine specific methods in a class. My problem is that I want 
> my test class to inherit from AR and my production and development class 
> to not inherit from AR. I could replace the prod/dev class with a mock 
> class that replaces the entire class (including the inheritance) - if 
> Ruby supports this - but this would not be DRY since both classes would 
> be identical except for the fact that one inherits from AR. Perhaps I am 
> missing something?
> 
> Can you (or anyone) shed any light on this?
> 
> Thanks,
> Martin
Well, I think I solved my own problem and I''d share the solution with 
the list.

The requirement was that the class should inherit from AR when in test 
mode only and at the same time not repeat the code for the class. I did 
this through defining the class in question as a Module and then mixin 
it in to the appropriate class:

    Module Class_with_code
      ...
    end

    if (ENV["RAILS_ENV"] == "test")
      class Class_to_use <  ActiveRecord::Base
        include Class_with_code
      end
    else
      class Class_to_use
        include Class_with_code
      end
    end

I knew there was a simple (and elegant) solution!

Martin

-- 
Posted via http://www.ruby-forum.com/.