[Zope3-dev] Re: Zope3/src/zope/app/browser/skins/debug/exceptions.py:1.1

[Jim Fulton]

Steve Alexander wrote:
...

>>> The query:
>>>
>>>   I'm pretty sure that __used_for__ has been a single interface,
>>>   not a tuple of interfaces. Was there a particular reason you used
>>>   a tuple?
>>
>>
>> Nope.  I think I saw it that way someplace, but could be wrong.  I
>> thought of it as syntactically similar to __implements__.
> 
> 
> Good point. I guess this should be reevaluated when the new interfaces 
> proposal is implemented.

__used_for__ should be a single interface.  Allowing multiple interfaces
here would also require that adapters and view me registered for multiple
interfaces. This would complicate lots of things. I really don't want to
go there unless there is a really compelling need.

> 
>>>   Classes in Zope 3 should usually be new-style classes rather
>>>   than classic classes. This is usually done using
>>>
>>>     __metaclass__ = type
>>>
>>>   at the module level.
>>>
>>>   This is important for views, as the code that sets up views from zcml
>>>   directives sometimes does some fancy things that only work properly
>>>   with new-style classes.
>>
>>
>>
>> Cool.  I've seen that, but didn't know when / why to follow suit.
> 
> 
> As a rule, whenever the module contains classes that don't derive from 
> other classes.

IMO, this is a matter of taste.

I personally, have come to dislike inheritance. I somehow find it
more satisfying to see:

   class C:

      ....


rather than:

   class C(object):

which seems redundant to me, as all classes should be new-style classes.

I don't feel very strongly about this.

> 
>> I hadn't considered that the module was doing anything testable, and was
>> looking at the content of the other two skin directories when I built
>> 'debug'.  Neither of '{rotterdam,zopetop}/standardmacros.py' has tests
>> (but they don't do much interesting, either).
> 
> 
> The rotterdam/standardmacros.py and zopetop/standardmacros.py should 
> have a minimal unit test.
> 
> A typical scenario is:
> 
>   * Joe Developer corrects a typo in a comment in standardmacros.py
> 
>   * Unfortunately, his finger slips and he introduces a syntax error,
>     or deletes a name from a variable, without realising it
> 
>   * Joe runs all the unit tests before checking in with no problems
> 
>   * Joe also starts up Zope, and it seems to work and render some
>     basic pages in the browser
> 
>   * Joe checks in the broken code
> 
> Actually, because these classes are refered to in zcml, the 'functional' 
> test of starting up Zope should catch any syntax errors. However, 
> unplanned changes in variable names would still slip through.
> 
> Have I made a good enough case to persuade the zopetop/rotterdam 
> maintainers to add a unit test? ;-)
> 
> If they're too busy just now, they let me know and I'll write the tests.

We *really* need a functional testing framework.

I'm going to try to make this a priority soon.

Jim

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