Add a config object param to all metric functions

[philipwalton]

Fixes #224 by adding a optional, configuration object as the second parameter for all metric function.

This PR also adds the ability to set the durationThreshold parameter when measuring INP, which is useful if you to get more granular debug data on interactions that are already relatively fast (the default durationThreshold is 40).

Here's an example of how you can set the lowest supported durationThreshold value supported in browsers.

import {onINP} from 'web-vitals';

onINP(console.log, {
  durationThreshold: 16,
  reportAllChanges: true,
});

[rviscomi]

Should the WV extension use this? Not sure if it would help clear the "waiting for interaction" message sooner.

[philipwalton]

Yeah, it potentially could. The main unknown is what the performance impact is of setting to a lower threshold actually is. @mmocny is planning to run some benchmarks.

[rviscomi]

Is there an issue I can subscribe to where that's being tracked?

[mmocny]

https://bugs.chromium.org/p/chromium/issues/detail?id=1321807

Not sure how highly to prioritize that work. Let us know demand in the bug :)

[rviscomi]

Thanks. The reporting lag in the extension did throw me off, but I'll let you know if there's additional developer feedback to make this a higher priority.

We can also make the duration threshold configurable in the extension options, so developers can choose to trade performance for better reporting.

[mmocny]

Reporting lag I think is likely to come from something other than slowness of the PerformanceObserver API itself. When responsiveness sucks, it's likely due to main blockage, which itself blocks the INP snippet. But yes, the default 40ms right now means sometimes it feels like its not working. Philip previously suggested one simple fix is to use the FID event for the initial INP value, for cases where INP<durationThreshold.

…

-Michal

On Wed, May 11, 2022 at 3:29 PM Rick Viscomi ***@***.***> wrote: Thanks. The reporting lag in the extension did throw me off, but I'll let you know if there's additional developer feedback to make this a higher priority. We can also make the duration threshold configurable in the extension options, so developers can choose to trade performance for better reporting. — Reply to this email directly, view it on GitHub <#225 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AADTZKRE4B3W7FDXJX6FRADVJQDBXANCNFSM5VV2ALLQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>