What do you think about this hack to enable `SomeE...

# javascript

[Marc Knaup]

What do you think about this hack to enable SomeExternalInterface.someFun()? 🤔
This actually compiles and works. this will be null in SomeDslClass.Companion.foo which is okay because it’s not actually used.
It allows for a nice DSL with zero overhead for unused Kotlin interface types and companion classes.

external interface SomeDslClass {
    @Suppress("NESTED_CLASS_IN_EXTERNAL_INTERFACE")
    companion object
}

fun SomeDslClass.Companion.foo() {
    console.log("it works!")
}

fun main() {
    SomeDslClass.foo()
}

[turansky]

Companion - legal solution, which already used by Kotlin/JS browser classes

[Marc Knaup]

I gave up on that for now due to another limitation :(
https://youtrack.jetbrains.com/issue/KT-43448

[turansky]

In IR you can write inline extensions inside external interface

It works!

[Marc Knaup]

It’s not an extension if I write it directly inside the Companion.

[turansky]

https://youtrack.jetbrains.com/issue/KT-40235?

[Marc Knaup]

What I need is a non-external companion 🙂

[turansky]

Like this?

external interface X {
    companion {
        inline fun foo() {
            println("It works!")
        }
    }
}

[Marc Knaup]

Hmm, inline is a good idea. I’d just have to add an additional function to hide away internal/private API which is blocking internal 🤔

[Marc Knaup]

I’ll give it a thought.

And idea how to nest non-external interfaces inside external interfaces 😄

[Marc Knaup]

Oh wait, I also use val without getter in some of my Companions. That won’t work.

[turansky]

Yes, inline required

[turansky]

Sugar for external - inline

[turansky]

Inline without @Suppress - https://youtrack.jetbrains.com/issue/KT-42871

[turansky]

Feel free to vote :)

[Marc Knaup]

done 🙂

[turansky]

Possibly you also need external “options” 🙂

[Marc Knaup]

No, I try to avoid interacting with JS as much as possible 😅

[turansky]

React props - external options too 🙂
Do you use React?

[Marc Knaup]

Yes, but I've written a wrapper so that all my props are regular Kotlin classes.