Is `accountNumber` ```data class Account ( @ge...

# getting-started

[David Kubecka]

Is accountNumber

data class Account (
    @get:JsonProperty("accountNumber")
    val accountNumber: kotlin.String? = null
)

considered to have a custom getter? Because that's what compiler complains about when I try to do this:

val account: Account = TODO()
checkNotNull(account.accountNumber)
val number: String = account.accountNumber // error here

Why is it so?

[Riccardo Lippolis]

works for me 🤔 , what error are you getting?

[dmitriy.novozhilov]

It is a bug, which was fixed by K2 compiler
Works fine with 2.0.0

[dmitriy.novozhilov]

Actually there is still an issue with this code in case of incremental compilation, which is not fixed yet: KT-69075

[David Kubecka]

Actually, my data class comes from an external module. Will smart casting ever be possible in such a situation?

[dmitriy.novozhilov]

Smartcasts on properties from other modules are prohibited by design: there is no guarantee that on runtime you won't receive a library of a different version, which, for example, added the custom getter

[David Kubecka]

Ok, maybe a silly question: Why is @get:JsonProperty("accountNumber") considered a custom getter? It actually doesn't influence the field value in any way, does it?

[dmitriy.novozhilov]

For properties from other modules there is no difference if there are annotations on accessors or not. There shouldn't be smartcast even without an annotation