[Question] How to connect Lighthouse CLI to Android's app webview

I know how to connect to Google Chrome on Android (by forwarding tcp:9222 localabstract:chrome_devtools_remote), but I can’t find how to run a lighthouse test for a debuggable webview in an app. Webview is visible in chrome://inspect and I can run an audit from there but I need to pass custom config to the LS test.

Passing a config file through desktop Chrome would be also good enough for my use case but automating it with CLI would be even better.

[patrickhulce]

Could you please share how does Google Chrome connects to the app’s webview when it’s not possible with CLI yet?

The DevTools integration is built specifically to keep the existing page intact. It does not use the same target creation path that the node/CLI uses.

And is there a way to use special config file with Chrome’s Lighthouse audit?

Not without a lot of work 😃 You could use a custom-devtools-frontend and modify the config used by Lighthouse, but it’d probably be easier to just redeploy the page in a way that’s accessible from proper Android Chrome 😅

[patrickhulce]

Can you share more about that topic or point me to a place where I could learn it myself?

DevTools reimplements its own custom connection class that does not create new targets like the node/CLI path does.

This is the bit of code used by node/CLI that creates a new target to evaluate when lighthouse connects to Chrome.

https://github.com/GoogleChrome/lighthouse/blob/800ffd6da37e1be6712b04906d9abc701ff49fb6/lighthouse-core/gather/connections/cri.js#L36-L53

You would need to implement your own connection that skips this step in node.

DevTools basically needs to communicate in a way that should be reproducible using CLI Tools - a combination of adb and lighthouse probably?

As seen above, it’s not the communication method that’s the problem, it’s the fact that new targets are created.