[Freeipa-devel] [PATCHES] 0094-0099 Make Fuzzy objects available for the whole ipatests module

[Petr Viktorin]

On 09/13/2013 07:04 PM, Rob Crittenden wrote:
> Petr Viktorin wrote:
>> On 09/13/2013 04:12 PM, Tomas Babej wrote:
>>> Hi,
>>>
>>> The following patches move and extend the functionality of Fuzzy
>>> objects. This is necessary to use them from within integration tests.
>>
>> -1 to the idea.
>> I'm not a fan of the Fuzzy objects; they basically exist so that you can
>> use regex matching in the Declarative tests.
>> As you've probably noticed Fuzzy is quite specific to the framework and
>> its test suite -- see the strict bytes/unicode separation and the amount
>> of changes it takes to tear them out.
>>
>> I'm also not a fan of having a generic "Match anything using some rules"
>> object where everybody adds behavior specific to their use case. Each
>> addition increases the complexity and number of corner cases, and the
>> complete intended functionality can never be achieved.
>>
>> Using regular expressions directly should actually be easier and less
>> error-prone in most cases.
>> If you disagree, I'd like to see your use case.
>
> I'm not sure what the objection is, Fuzzy is just an abstraction. It
> lets one do in-line regex which is the reason it was introduced
> (initially for uid and gid because they are non-deterministic).

Yes. "In-line" is the key here. It lets you do regex matching via the == 
operator, which is what Declarative tests need, but elsewhere the 
abstraction is completely unnecessary.

> Replacing it would either a) replicate its functionality almost
> completely or b) spread duplicate regex code all over the place.

I'd go for b; spreading this code:
     import re
     some_regex = re.compile('some.*regex$')
     ...
     assert some_regex.search(x)
instead of:
     from wherever import Fuzzy
     warm_fuzzy = Fuzzy('some.*regex$')
     ...
     assert x == warm_fuzzy
all over the place is fine in my book. And you can even, say, add custom 
flags to the regex without complicating shared code.

The rest of Fuzzy functionality consists of strict type checking (which 
isn't really necessary in integration tests), and the ability to call 
arbitrary callables (which is just the scope creep I was talking about).
By the way, in current tests these features are hardly ever used in 
combination.
Even if this extra functionality is necessary, it's orthogonal to regex 
matching and can be more cleanly done with several separate asserts. 
Unless you need a single declarative object to compare against, of course.

> That isn't to say that Fuzzy isn't being abused, but that is also the
> responsibility of the reviewers to be strict about.

Then perhaps I'm too strict, but I say that using it outside of the 
declarative tests is abuse.
Especially if it takes six patches with hundreds of changed lines to 
repurpose Fuzzy for integration tests (but that's not part of "-1 to the 
idea").

-- 
Petr³