[rspec-users] [rspec] Stubbing partials in view specs / Test Spy

Scott Taylor scott at railsnewbie.com
Thu Mar 19 11:39:23 EDT 2009


On Mar 19, 2009, at 10:30 AM, David Chelimsky wrote:

> On Mar 19, 2009, at 7:59 AM, Evgeny Bogdanov <evgeny.bogdanov at gmail.com 
> > wrote:
>
>> just upgraded to 1.2.0
>> the following code works now:
>>
>>   template.stub!(:render).with(hash_including(:partial => "children/
>> child"))
>>   template.should_receive(:render).with(hash_including(:partial =>
>> "children/child"))
>>
>> The only question that is left for me is about Nick's words:
>> "If you set a method expectation on an object (IE:
>> template.should_receive(:render) ), you don't need to stub the method
>> (IE: template.stub!(:render) isn't needed)."
>>
>> Basically, there are two situation.
>> 1) I want to check if a function was called and I want to execute the
>> function code
>> 2) I want to check if a function was called and I don't want to
>> execute the function code so I used stubbing.
>>
>> I thought that for the first scenario the solution would be:
>> template.should_receive(:render) #only checks if render function was
>> called
>>
>> and for the second scenario
>> template.stub!(:render) #stub render function
>> template.should_receive(:render) #check if render function was called
>>
>> Am I right?
>
> No. What I think you're describing is called a test spy: a means of  
> monitoring interactions without changing the behavior. RSpec's mocks  
> don't provide this. The only ruby framework I'm aware of that does  
> is RR. There may be others.
>

"Before we exercise the SUT, we install a Test Spy as a stand-in for  
depended-on component (DOC) used by the SUT. The Test Spy is designed  
to act as an observation point by recording the method calls made to  
it by the SUT as it is exercised. During the result verification  
phase, the test compares the actual values passed to the Test Spy by  
the SUT with the values expected by the test. "

http://xunitpatterns.com/Test%20Spy.html

Actually, the "Not A Mock" framework also supports the test spy pattern:

http://github.com/notahat/not_a_mock/tree/master

Scott


> A stub (stubs!) overrides an existing method (if one exists) and  
> returns either self or any value you define with and_returns.
>
> A message expectation, or mocked method (should_receive) does the  
> same thing *plus* it verifies that the message was called.
>
>
> HTH,
> David
>
>>
>>
>> Thanks,
>> Evgeny
>>
>> On Mar 18, 11:23 pm, Zach Dennis <zach.den... at gmail.com> wrote:
>>> On Wed, Mar 18, 2009 at 6:18 AM, Evgeny Bogdanov
>>>
>>>
>>>
>>> <evgeny.bogda... at gmail.com> wrote:
>>>> Hello,
>>>> I have a problem similar to one mentioned in this post.
>>>> I call a partial inside another partial.
>>>> _mother.haml contains:
>>>> render :partial => "children/child"
>>>
>>>> In mother_spec.rb file I am trying to stub the render call.
>>>> Here is a working version:
>>>> =============
>>>>   template.should_receive(:render)
>>>>   template.stub!(:render)
>>>
>>>>   render :partial => 'mother'
>>>> ============
>>>> I would prefer to specify that the partial I am stubbing is  
>>>> "children/
>>>> child",
>>>> however the following code doesn't work for me:
>>>> ===========
>>>>   template.stub!(:render).with(hash_including(:partial =>  
>>>> 'children/
>>>> child'))
>>>>   template.expect_render(:partial => 'children/child')
>>>
>>> What version of rspec are you using? #expect_render has been removed
>>> in rspec 1.2 and has been deprecated for a while before that so you
>>> won't want to rely on that unless you're using an old version of
>>> rspec.
>>>
>>>
>>>
>>>>   render :partial => 'mother'
>>>
>>>> : Mock 'render_proxy' expected :render with ({:partial=>"children/
>>>> child"}) once, but received it 0 times
>>>> ===========
>>>> Is it possible to stub the render call with specific partial name?
>>>
>>> You had it right, hash including should work:
>>>   template.stub!(:render).with(hash_including(:partial =>  
>>> "children/child"))
>>>
>>> To stub all partials being rendered:
>>>   template.stub!(:render).with(hash_including(:partial => anything))
>>>
>>> HTH,
>>>
>>>
>>>
>>>
>>>
>>>> Thank you in advance,
>>>> Evgeny
>>>
>>>> On Jan 20, 5:35 pm, Bart Zonneveld <zuperinfin... at gmail.com> wrote:
>>>>> On 20-jan-2009, at 15:29, David Chelimsky wrote:
>>>
>>>>>> On Tue, Jan 20, 2009 at 7:44 AM, Bart Zonneveld
>>>>>> <zuperinfin... at gmail.com> wrote:
>>>>>>> Hey list,
>>>
>>>>>>> As a good BDDer I want to test my views in isolation.
>>>
>>>>>> Sort of. A *good* BDDer wants to *specify* views in isolation.  
>>>>>> Testing
>>>>>> is for testers :)
>>>
>>>>> You're right! I tend to talk a lot to non-programmers, and they  
>>>>> get
>>>>> that glaze-in-the-distance look in their eyes, whenever I mention
>>>>> specifiy, spec'ing, or what have you :).
>>>
>>>>>>> And as a good rails
>>>>>>> programmer, I separate views into partials when needed. So, when
>>>>>>> testing my
>>>>>>> views, I want tostubout rendering of partials in my views. I'm
>>>>>>> working on
>>>>>>> upgrading an app from rails 2.1.2 to 2.2.2, using the latest  
>>>>>>> rspec
>>>>>>> and
>>>>>>> rspec-rails.
>>>
>>>>>>> I used to throw template.stub!(:render) in a before(:each) block
>>>>>>> and be done
>>>>>>> with it
>>>
>>>>>> That sounds kinda risky because you could be ignoring partials  
>>>>>> that
>>>>>> get rendered that you don't want to be rendered.
>>>
>>>>> It is, most definately.
>>>
>>>>>>> , but that doesn't work anymore. I can understand why, but now  
>>>>>>> I have
>>>>>>> to do something like template.stub!(:render).with(hash_including
>>>>>>> (:partial =>
>>>>>>> anything)). Except for when I'm testing a partial, then I need  
>>>>>>> to
>>>>>>> replace
>>>>>>> the anything with every partial I'm rendering in my partial.
>>>
>>>>>>> Is this the correct way,
>>>
>>>>>> Seems like the only way at the moment. Wouldn't call it correct  
>>>>>> or
>>>>>> incorrect.
>>>
>>>>> I would call it ugly :). Not only do I have to remember the
>>>>> hash_including part, but also the anything (and not :anything).
>>>>> Conceptually, I like the template.stub!(:render). Irendera
>>>>> template, on which Istuball the renders. Whether that's risky or
>>>>> not is a different discussion.
>>>
>>>>>>> or is there perhaps something like
>>>>>>> template.stub_partials :only => [], :except => [] ?
>>>
>>>>>> Nothing like this exists. Seems like a reasonable idea. Feel  
>>>>>> free to
>>>>>> submit a feature request, or better yet, a patch to
>>>>>> http://rspec.lighthouseapp.com
>>>
>>>>> Will do!
>>>
>>>>> cheers,
>>>>> bartz
>>>
>>>>> _______________________________________________
>>>>> rspec-users mailing list
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>>>> _______________________________________________
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>>>
>>> --
>>> Zach Dennishttp://www.continuousthinking.comhttp://www.mutuallyhuman.com
>>> _______________________________________________
>>> rspec-users mailing list
>>> rspec-us... at rubyforge.orghttp://rubyforge.org/mailman/listinfo/rspec-users
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