[Zope3-dev] Re: The bug fixing problem

[Jim Fulton]

On Jul 7, 2006, at 7:52 AM, Christian Theune wrote:

> Hi,
>
> Jim Fulton wrote:
>> On Jul 6, 2006, at 12:29 PM, Philipp von Weitershausen wrote:
>>> dieter at handshake.de wrote:
>>>> Christian Theune wrote at 2006-7-5 11:46 +0200:
>>>>> ...
>>>>> Another thing are the rules about unit tests. Some bugs touch  
>>>>> areas that
>>>>> are poorly tested. When I fix a bug over there, do I have to  
>>>>> work harder
>>>>> to introduce the fix because I have to start introducing tests?
>>>>> We should find and announce a reasonable answer for the  
>>>>> procedure in
>>>>> this case.
>>>>
>>>> Although I have (so far) never fixed a bug in Zope 3 (but posted
>>>> several patches for Zope 2), I can confirm this:
>>>>
>>>>    There are bugs that do not need a test once they are fixed.
>>>>    All kinds of "NameError" and "AttributeError" fall into this
>>>>    category.
>>>>
>>>>    Requiring to write a unit test for these or similarly trivial
>>>>    bugs is silly -- especially if there is not yet a testing file
>>>>    for the module (such that a trivial test would suffice).
>>>
>>> I disagree. How would you make sure that your fix for even a  
>>> "trivial"
>>> NameError actually works? Perhaps you introduced another typo in the
>>> bugfix? Or perhaps another problem pops up in the same codepath.
>>> Clearly, since the NameError didn't occur in any other tests, the
>>> codepath hasn't been tested yet, so it should be no matter what.
>>>
>>> There's another aspect to tests for bugs: reproduceability.  
>>> Especially
>>> when fixing bugs I tend to write tests first in order to be  
>>> absolutely
>>> sure that I can reproduce the problem in an automated manner. Then
>>> fixing the bug is "easy": Just make the test pass...
>> Well said. I agree 100%
>
> Just to make sure nobody got me wrong: I'm not arguing that tests  
> are a bad thing. They belong to the best thing that came up in the  
> last years. :)
>
> I was merely pointing to a small edge-case in bugfixing, that might  
> be even smaller then anticipated, where I got frustrated in the  
> last time.
>
> +1 for the tests-are-good-recap :)

And just to make sure that I was clear, when trying to urgently go  
through
bugs for a release, I think it's OK to provide a test for just the fix.

If, in the course of a fix, you notice that a package is short of tests,
it would be great to add more then, but it would be OK to just turn that
lack of tests into a separate non-urgent bug entry.

Jim

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