[webkit-dev] Supporting <link rel=> for finding ref tests

[Simon Fraser]

> On Nov 12, 2019, at 4:52 AM, Frédéric Wang <fwang at igalia.com> wrote:
> 
> On 09/11/2019 04:02, Ryosuke Niwa wrote:
>> 
>>>>>  - Requires us modifying each port's DRT to support this format
>>>>> 
>>>>> No, it just requires webkitpy hacking which I've done in the patch.
>>>> I'm not certain writing a bunch of regular expressions in webkitpy is
>>>> a reliable mechanism to find expected results. Another issue I found
>>>> back then was that it significantly slowed run-webkit-tests' startup
>>>> time because WPT has a workflow to find all tests & their expected
>>>> results upfront before any tests could run.
>>> The patch uses html5lib (via BeautifulSoup), which is exactly what WPT, and our importer use to find the ref tests.
>>> 
>>> We don't find references up-front; only when running each test. This patch does add some overhead for parsing each test file,
>>> which I measured to be about 1-2 sec on a directory which took 30s to run. I think this slight slowdown is worthwhile (we could
>>> probably eliminate it with some webkitpy optimizations).
>> Hm... that's ~3% overhead.
> 
> @Simon: I agree with Ryosuke that 3% sounds big. IIUC you are parsing
> the HTML file when running each test? I thought that there is a
> MANIFEST.json file which is supposed to cache that information, why
> can't we use it?

I don't see any files call MANIFEST.json in the wpt repo.

There are reftest.list files but these are obsolete.

I hope to get that 3% back by other webkitpy perf optimizations (python optimization hints welcome).

Simon