1976515 - Allow adding use counters for unimplemented dictionary fields

Status: NEW

(Core :: DOM: Bindings (WebIDL), task)

Description

[Kagami Rosylight [:saschanaz] (they/them)]

This should be possible without making it web-visible, with some Object.hasOwn-equivalent check while doing the dictionary initialization via JS value.

Comment 1

[Kagami Rosylight [:saschanaz] (they/them)]

Hmm, proxies can still catch hasOwn via getOwnPropertyDescriptor...

o = new Proxy({}, { getOwnPropertyDescriptor(target, prop) { console.log(target, prop)} })
Object.hasOwn(o, "foo") // triggers the callback

But perhaps we have some internal native function to not trigger that. Matt, do you know? 👀

Edit: Maybe js::NativeLookupOwnProperty.

Comment 2

[Matthew Gaudet (he/him) [:mgaudet]]

Whay you're looking for is the Pure family of functions -- now we may need to export them as js/friend functions, but the gist is that they will try to look up a property, but will decline to trigger getters or GC.

This is perfect for telemetry.

So what you want is LookupPropertyPure

Comment 3

[Kagami Rosylight [:saschanaz] (they/them)]

Sounds great, thank you!