Preloaded scripts warning

[steida]

It's the same like #2022

The resource was preloaded using link preload but not used within a few seconds from the window's load event. Please make sure it has an appropriate `as` value and it is preloaded intentionally.

I am not doing anything weird. Just Link prefetch. It seems it's probably ok, but it can be confusing so maybe docs can be updated.

GoogleChromeLabs/preload-webpack-plugin#8 (comment)

[pantharshit00]

I can confirm this.

Chrome Version: 72.0.3626.121

Even zeit.co has these warnings:

I think we should use link prefetch for these routing operations as these are not being immediately consumed by the user.

[developit]

Just confirming from the Chrome side here - the way Next is preloading is totally fine. We're hoping to turn off these warnings for resources preloaded with priority=low once that ships.

As a comparison point, if these resources were preloaded via a Service Worker, we wouldn't show any warnings even though the same amount of networking is being done.

[joaovieira]

I just noticed all of our prefetched links are being downloaded with High priority.

While <NextScript>s make sense to be preloaded as they'll all be needed for the current page, any link prefetched with <Link prefetch> is a hint that the page/bundle might be needed in the future. Couldn't we use <link rel="prefetch"> in that case?

As is, prefetched bundles are being downloaded with High priority instead of Low, unnecessarily. Or am I missing something (e.g. Safari support)?

[Odrin]

Why is this closed? According to this google article we should use prefetch instead of preload. At least this should be configurable. And Link prop name prefetch is very confusing at this point.

[trainto]

Firsit time I saw the warning, I thought I've must done something wrong. I tried to figure it out what caused this warning, and I ended up finding that messages also can be seen even nextjs.org site.
I think it should be handled to prevent spending hours for nothing like me.

[okeybond]

sorry, this is still an issue,

[timneutkens]

sorry, this is still an issue,

#6517 (comment)