Preload audit on lazy iframe

[kirill-chirkov-at-clouty]

Provide the steps to reproduce

Run LH on https://www.clouty.ru/shop-item/9cedcb77-e064-40a5-9765-1e79152d83bc/jackets-zhaket-emporio-armani

What is the current behavior?

Audit suggests me to Preload key requests on iframe with src https://www.clouty.ru/toshop?id=9cedcb77e06440a597651e79152d83bc&type=iframe.
Iframe is injected lazily via js, some time after onload browser event and serves pure technical needs.

What is the expected behavior?

Preloading this specified iframe would ruin the lazy behavior, but preload audit lowers score significantly

Environment Information

• Affected Channels:
• Lighthouse version: 4.0.0-alpha.2-3.2.1, 4.0.0-alpha.1, 3.2.1 and 3.0.3 (Chrome Lighthouse audit)
• Node.js version: 10.13.0
• Operating System: Windows 10 Pro 64-bit

Related issues
#4425 (comment)

[wardpeet]

@patrickhulce I did some research on this and when looking into devtools we get a resourceType of undefined back because it's a 302 so my suggestion is to hide 30x from this list too. Maybe this is considered a chrome bug but at least devtools does this wrong as well.

[patrickhulce]

Yeah I think that's a good call @wardpeet! 👍

[patrickhulce]

Oh I just realized that might be because of OOPIFs (#6337), still makes sense to do your filter I think though until we have the protocol support we're waiting on.

[brendankenny]

fixed in #6704 and verified that it no longer shows up in the report for this site. Additional preload improvements will continue to happen in #4425