One more newbie question :slightly_smiling_face:. ...

# javascript

[julien lengrand-lambert]

One more newbie question 🙂. I have defined a List in the external interface. Except it doesn't behave like a kotlin list as I'm hitting a lot of Uncaught TypeError: ensureNotNull(...).iterator_0_k$ is not a function errors (same for `ìsEmpty`and any other idiomatic List function).

external interface FirestoreMessage{
    val id: String
    val content: String
}

@JsModule("@jlengrand/firebase-ports")
@JsNonModule
external object FirebasePorts{
    fun logIn() : Promise<FirebaseUser>
    fun logOut()

    fun saveMessage(uid: String, message: String)
    fun getMessages(uid: String) : Promise<List<FirestoreMessage>>
}

Do you have a reference on how to use lists in external interfaces by any chance?

[julien lengrand-lambert]

Ok, It looks like Array does the job, but List do not seem to be supported

[Big Chungus]

You can't with IR backend for now. Use Arrays instead.

[Big Chungus]

The reason is that List is not external nor mapped to a native js type

[Grégory Lureau]

You can have a look at KustomExport, it's an experimental library I'm writing to support this kind of missing features.

[turansky]

1. In simple cases you will write the same code for Array and List
2. Array is faster than List (it was research in this channel - x10 in some cases)
3. Immutable Array also exists

[julien lengrand-lambert]

Thanks all! nice to see that Deezer uses Kotlin JS @Grégory Lureau 🙂