any nicer way to write something like this?

list.none { it is State.StateA } shouldBe true

Goal is, to check if the list does not contain an element which matches a given predicate

Hi @Henning B, that looks good to me but perhaps if you have a known value then you may alternatively use

!in

val x: Boolean = listOf(1, 2, 3).none { it == 1 } //false
val y: Boolean = 1 !in listOf(1, 2, 3) //false

Maybe:

list shouldNot singleElement { it is State.StateA }

You could also extract this into another function like

infix fun <T> Collection<T>.shouldNotHaveSingleElement(t: T) = this shouldNot singleElement(t)

There is always .forNone too

Thanks!

somewhat related, perhaps you have some opinions to add https://github.com/kotest/kotest/pull/2321 🙂