Highlight third parties with unload event handlers? #185
Description
Would it be possible to highlight third parties that still rely on unload event handlers?
Those break the back/forward cache on some browsers, and are unreliable on other browsers or mobile platforms.
There are better alternatives available which don't have these downsides (e.g. visibilitychange).
More details in this lighthouse issue.
We did a large outreach to increase awareness and successfully convince lots of third parties to migrate away from unload event handlers, but there is still a long tail of third parties... Perhaps, thirdpartyweb could help raise awareness at scale?
Here is a query that should give a list of unload event handler sources:
SELECT COUNT(*) AS CNT, unload_source, unload_line, unload_column
FROM `httparchive-lighthouse.BestPractices.unload_sources`
GROUP BY unload_source, unload_line, unload_column
ORDER BY CNT DESC LIMIT 1000;