Third-party Google Assets don't follow their own audit rules, causing report errors

When I run lighthouse reports, my only errors and warnings come from assets delivered by the creator of lighthouse: Google.

Specifically, this warning/error shows up.

Uses inefficient cache policy on static assets

All the items in this report come from

• securepubads.g.doubleclick.net (google property).
• googletagmanager.com (google property)
• pagead2.googlesyndication.com (google property)
• www.google-analytics.com (google property)
• tpc.googlesyndication.com (google property)

Why does Google serve assets that fail to follow their own recommendations as based on lighthouse? If they recommend static assets be sent with proper caching headers, why doesn’t google follow through with that? Some of their assets have a ttl of 0 or 15m!

If they aren’t going to follow their own recommendations, then it seems that lighthouse should exclude their own domains from this analysis, since it creates a bunch of false positives which I can do nothing about.

[apotek]

Yes, allowing us to filter them out would be helpful. I’m wondering, though, if there is a way to open an issue with Google regarding how they cache their JS. I’ve never understood why some of their libraries are set to ttl 0 or 15 minutes, etc… I doubt they are releasing code updates every fifteen minutes 😃. It just seems since lighthouse was affiliated with Google development, that maybe they could nudge Google to observe its own rules and recommendations.

Thank you for your response @patrickhulce . I suppose filtering will not affect the score, which will remain affected by Google’s caching errors, but at least we could then reduce noise during our weekly testing.

[paulirish]

Let’s add private to our list. And land the 3P filter.