[rspec-users] Problems with mock assigned to a constant

[Scott Taylor]

On Jul 25, 2008, at 1:05 AM, Matt Lins wrote:

> On Thu, Jul 24, 2008 at 11:38 PM, Scott Taylor
> <mailing_lists at railsnewbie.com> wrote:
>>
>> On Jul 25, 2008, at 12:21 AM, Matt Lins wrote:
>>
>>> Scott,
>>>
>>> Thanks, your solution does work, although I'm not sure I like it.  I
>>> like to stub out behavior in my before block but also use mock
>>> expectations to verify behavior in my specs.  Similar to what Dave
>>> explains here:
>>>
>>> http://blog.davidchelimsky.net/2006/11/9/tutorial-rspec-stubs-and-mocks
>>>
>>> I defined the stubs in the before block:
>>>
>>> MyModel = mock('MyModel Class', :count => 1, :find => [@record])
>>>
>>
>> Ah - well, I missed this part.  This make much more sense.
>>
>> Btw, aren't you seeing warnings every time you run your specs?
>
> I'm not sure what code you're looking at, but in the gist paste I
> posted for this thread, I'm only defining the constant once(
> before(:all) ).  If you're looking at the lighthouse code, I was
> undefining the constants in the after block.  So, no, I'm not seeing
> warnings.
>
>>
>> Redefining the constant for your test, is, IMHO, the most ugly  
>> solution you
>> can take (and plus, it'll break in many circumstances - for  
>> instance, it
>> probably wont' play well with rails loading schemes).  One way  
>> around this
>> is by using dependency injection - I would highly recommend you use  
>> this
>> technique.  *DON'T* use the constant technique, unless you really  
>> know what
>> your doing.
>>
>
> Like I said I'm not redefining the constants.  Thanks for the insight,
> I'll research DI.
>
>> Unfortunately there are times when DI doesn't work (especially in  
>> the rails
>> world) - in those cases, you really have no other option besides  
>> stubbing
>> the class methods directly.
>>
>>> wiping out the stubs defined in the before block?  If that is the  
>>> case
>>> why does the first spec not fail because of MyModel.find ?
>>
>> Well - what is happening between each test case?  Are the classes  
>> (defined
>> elsewhere) being reloaded each time?  Are you getting a warning  
>> when you
>> redefine MyModel?  Do you understand how rails is (re)loading this  
>> stuff?
>>
>
> All my code for the example was posted in gist ( you can download it
> if you'd like ).  I'm not using Rails, I'm writing a library that uses
> ActiveRecord.  But, all that is mocked out.  The example in gist fully
> illustrates the problem in my actual library.  The output that I
> posted in the first post is exactly what you get if you run the code
> pasted in gist:
>
> http://gist.github.com/2372
>
> Sorry, if that was confusing, I shouldn't have even mentioned the
> lighthouse ticket.
>

No - it was my own fault.  I didn't take the time to read your post  
fully.

Anyway - DI is surely the way to go.  And generally you'll want to  
stay away from before(:all) when you can.

Best,

Scott