[webkit-dev] A simpler proposal for handling failing tests WAS: A proposal for handling "failing" layout tests and TestExpectations

[Dirk Pranke]

I'm not sure if I like this idea or not. A couple of observations/questions ...

1) I wouldn't want to call it '-correct' unless we were sure it was
correct; '-previous' is better in that regard

2) the issue with keeping a '-correct' in the tree is that it's quite
possible for a previous correct expectation to need to change to a
different expectation to still be correct. i.e., they get stale. I
fear that this could quickly become more confusing than it's worth.
It's also not clear to me when -previous gets updated or removed?

3) It also feels like '-previous' is something that we can just as
easily get from SVN/Git/whatever, in a completely foolproof and
automatic way. I grant that it's easier to just do a side by side
compare, but "diff against previous" isn't that hard to do and we
could easily write a wrapper to make it trivial ...

4) I'd want to work through the various branches in the workflow more
before I felt comfortable with this. When I was coming up with my
original proposal I originally wanted to allow -passing and -expected
to live side-by-side, but all sorts of complications arose, so I'd be
worried that we'd have them here, too.

-- Dirk

On Fri, Aug 17, 2012 at 6:51 PM, Ojan Vafai <ojan at chromium.org> wrote:
> That matches my understanding. You proposed modification sounds fine to me.
>
> On Fri, Aug 17, 2012 at 6:40 PM, Maciej Stachowiak <mjs at apple.com> wrote:
>>
>>
>> My understanding of the current proposal is this:
>>
>> 1) This applies to tests that fail deterministically, for reasons other
>> than a crash or hang.
>> 2) If the test has a new result that you're confident is a progression (or
>> neither better or worse), you simply update the -expected.txt file.
>> 3) If the test has a new result that you're confident is a regression, you
>> delete the -expected.txt file and check in the new results as -failing.txt.
>> 4) Ditto points 2 and 3 with respect to -expected.png, for image diffs.
>> 5) We would stop using all other ways of marking tests that fail
>> deterministically, including Skipped and the many things you could enter in
>> TestExpectations.
>>
>> Is that correct?
>>
>> If so, I'd like to suggest a minor modification. In place of point 3
>> above, I propose the following:
>>
>> 3) If the test has a new result that you're confident is a regression, you
>> rename the -expected.txt file to -previous.txt (or maybe -correct.txt or
>> -pre-expected.txt or something) and check in the new results as
>> -expected.txt (unless there is already a -previous.txt, in which case just
>> update -expected and leave -previous).
>>
>> I propose this for the following reasons:
>>
>> - It maintains the longstanding approach that -expected.txt reflects what
>> is currently *expected* to happen, not whether it is right or wrong in some
>> abstract sense. It is an expectation, not a reference.
>> - It still leaves a clear indication of tests that somebody needs to look
>> at further, to determine if a regression occurred.
>> - It leaves both old and new result in place for easy comparison by an
>> expert.
>>
>> Regards,
>> Maciej
>>
>>
>> On Aug 17, 2012, at 6:06 PM, Ojan Vafai <ojan at chromium.org> wrote:
>>
>> +1
>>
>>
>> On Fri, Aug 17, 2012 at 5:36 PM, Ryosuke Niwa <rniwa at webkit.org> wrote:
>>>
>>> That's my expectation although we probably can't do that for flaky tests
>>> :(
>>>
>>> e.g. sometimes fails with image diff.
>>>
>>> On Fri, Aug 17, 2012 at 5:35 PM, Filip Pizlo <fpizlo at apple.com> wrote:
>>>>
>>>> +1, contingent upon the following: are we agreeing that all current uses
>>>> of TEXT, IMAGE, and so forth in TestExpectations should be in the *very near
>>>> term* following Dirk's change be turned into -failing files?
>>>>
>>>> -Filip
>>>>
>>>>
>>>> On Aug 17, 2012, at 5:01 PM, Ryosuke Niwa <rniwa at webkit.org> wrote:
>>>>
>>>> On Fri, Aug 17, 2012 at 4:55 PM, Ojan Vafai <ojan at chromium.org> wrote:
>>>>>
>>>>> Asserting a test case is 100% correct is nearly impossible for a large
>>>>> percentage of tests. The main advantage it gives us is the ability to have
>>>>> -expected mean "unsure".
>>>>>
>>>>> Lets instead only add -failing (i.e. no -passing). Leaving -expected to
>>>>> mean roughly what it does today to Chromium folk (roughly, as best we can
>>>>> tell this test is passing). -failing means it's *probably* an incorrect
>>>>> result but needs an expert to look at it to either mark it correct (i.e.
>>>>> rename it to -expected) or figure out how the root cause of the bug.
>>>>>
>>>>> This actually matches exactly what Chromium gardeners do today, except
>>>>> instead of putting a line in TestExpectations/Skipped to look at later, they
>>>>> checkin the -failing file to look at later, which has all the advantages
>>>>> Dirk listed in the other thread.
>>>>
>>>>
>>>> I'm much more comfortable with this proposal.
>>>>
>>>> - Ryosuke
>>>>
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>>>>
>>>
>>
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