Using when for a sealed interface does not show the "exhaustive" error

Support
1

I have the following code inside a .kt file:

sealed interface Animal {
    val name: String
}

data class SeaLion(override val name: String) : Animal

fun <T: Animal>manage(value: T) {
    when (value) {
        
    }
}

For some reason, the when block doesn’t display the expected compile time warning:

‘when’ expression must be exhaustive. Add the ‘is SeaLion’ branch or an ‘else’ branch.

However, if I change the file extension to .kts, it does display the warning. What exactly is going on here?

2

Check your Kotlin version, maybe? when statements were made exhaustive in 1.7