Run html5lib-tests against real browsers

[EmilStenstrom]

Hi,

Not sure if this is relevant to post here, feel free to close, but thought it might be helpful.

I've set up a testing bench where html5lib-tests can be run against three modern browser engines: Chromium, Webkit, Firefox: https://github.com/EmilStenstrom/justhtml-html5lib-tests-bench/

Results are pretty good!

Engine	Tests Passed	Agreement	Notes
Chromium 143.0.7499.4	1763/1770	99.6%	7 differing trees
WebKit 26.0	1741/1770	98.4%	29 differing trees
Firefox 144.0.2	1727/1770	97.6%	43 differing trees

[annevk]

Is that stable Safari? Safari Technology Preview should pass a couple more. See also https://wpt.fyi/results/html/syntax/parsing which does the same kind of thing.

[EmilStenstrom]

@annevk Updated the table above. The latest version available from Playwright: Webkit 26.0. How this compares to Safari Preview 26.3 is very unclear to me. Do updates land in webkit first, then in safari-preview?

For what it's worth, the above runs across all browsers in 9 seconds :)

[sideshowbarker]

FYI for the Gecko/Firefox HTML parser, I’ve got a couple of patches in the pipeline that’ll get us passing more tests there —

• Implement <select> parser “relaxation” — for “customizable” <select> validator/htmlparser#113
• Implement circa 2021 spec change for fragment parsing in foreign content validator/htmlparser#115