one thing that keeps bugging me is that @JsPlainOb...

# javascript

[Bernhard]

one thing that keeps bugging me is that @JsPlainObject does not implement ReadonlyRecordString, Any? so it's impossible to pass to APIs that work on records

I've deliberately typed some APIs with Any instead of Record

[turansky]

It's possible, but use case isn't transparent :(

[turansky]

Why do you need unsafe API, when you have safe? :)

[Bernhard]

some JS APIs take generic objects

[Bernhard]

for the ones that I'm typing

[Bernhard]

talking about template APIs specifically

[Bernhard]

so passing an object to a template engine is better typed using @JsPlainObject, but then I can't pass it into that function

[Bernhard]

because that function takes a record, so I can't pass in an interface if that makes sense

[Bernhard]

In my specific use case, looking at Handlebars:

var template = Handlebars.compile("Handlebars <b>{{doesWhat}}</b>");
template({ doesWhat: "rocks!" })

You might type the template function as

external fun template(context: ReadOnlyRecord<String, Any?>): String

But since you know which variables are used inside the template, you might want to define the parameter as

@JsPlainObject
external interface Context {
    val doesWhat: String
}
template(Context(doesWhat="rocks"))  // compile error

I think the solution is to generate a method/extension function called .toRecord()

template(Context(doesWhat="rocks").toRecord())

[Edoardo Luppi]

In the meantime you can create a Record yourself I suppose.

inline fun <K : Any, V> Any.toRecord(): Record<K, V> = unsafeCast<Record<K, V>>()

You could add whatever check to validate this

[Bernhard]

right, gonna go with that approach for now

[Bernhard]

or rather: write one extension function for every interface I need to

[Edoardo Luppi]

But I think the idea to have a plain object implement Record<K, V> is valid.
The meaning of safe interoping with JavaScript doesn't hold much value.

[Bernhard]

I think the main issue here is that js-plain-objects is in Kotlin core whereas record is in a community repo

[Bernhard]

are there any plans to merge this stuff together at some point?

[Edoardo Luppi]

Not that I know of. We currently have a very fragmented environment, indeed.

[turansky]

I think the main issue here is that js-plain-objects is in Kotlin core whereas record is in a community repo

It's not a blocker with K2

[turansky]

But I think the idea to have a plain object implement Record<K, V> is valid.

ReadonlyRecord - fine
Record - isn't fine

[Bernhard]

oh, that's great to hear 🙂