Lighthouse: Lighthouse audit does not take into account local overrides

[katenickerson]

Bug report

Lighthouse audit does not take into account local overrides.

Provide the steps to reproduce

1. Set up local overrides
2. Run LH on any URL
3. Make some local overrides to fix the problems revealed from Lighthouse
4. Run LH again

What is the current behavior?

The LH audit does not take into account the changes made from local overrides.

What is the expected behavior?

The LH audit should take into account the changes from local overrides, as demoed by Paul Irish at Google I/O.

Environment Information

• Affected Channels: Chrome DevTools (Version 67.0.3396.62)
• Operating System: macOS High Sierra 10.13.4

[paulirish]

This is true and it's a known issue. (Thanks for filing though; we had meant to have one by now)

This requires some engineering work to make it happen, but we'd like to take it on!

[jasongilmour]

This would be extremely useful for testing how big a performance boost certain changes would make very quickly - without waiting for a production build processes to run or having to spark up a back end server. Is there an ETA on this bug fix?

[paulirish]

No ETA, but we want this too. :)

Dev note: Requires supporting multiclient protocol for Audits panel

[javgar66]

still not working in canary Versión 72.0.3591.0

[alanbuxey]

still waiting for this essential help feature

[eduardosada]

It would be so nice to have this.

[wardpeet]

@paulirish is this something we can fix from Lighthouse end? If so feel free to brief me on this. I see the devtools label attached which makes me think this has to be done in devtools.

[cofinley]

In the meantime, a workaround can involve a local proxy like Charles or Fiddler to rewrite the server response(s). Was able to run audits on prod this way and didn’t notice any lag from the proxy’s interception.

[paulirish]

from #9095

reusing the same connection

Joel started a CL for this last summer. https://chromium-review.googlesource.com/c/chromium/src/+/1132548 We could resurrect that. We'd get local overrides, blocked URLs, protocol monitor and a few other things.

We'll also need to evaluate if emulation, etc state from devtools will apply during the LH run.

[connorjclark]

CL doing above: https://chromium-review.googlesource.com/c/chromium/src/+/1743411

Needed the multi-client changes to fix https://github.com/GoogleChrome/lighthouse/issues/9476.

We'd get local overrides, blocked URLs, protocol monitor and a few other things.

Confirmed all those things work with the above CL.

[connorjclark]

The multi-client CL just landed in Chromium. This issue will be resolved in the next canary Chrome. The first stable Chrome to resolve this issue will be Chrome 78, ETA Oct 22.

[qasimalyas]

I just ran into this issue and lovely to see it being fixed in canary, only two more days until its in stable. Great job 👍🏼

[connorjclark]

By my reckoning it's still 1 month away from landing in Stable. In Beta today tho!

[qasimalyas]

Too eager I guess 😋