using junit5/assertJ is there a way for the compiler to figure out that something cannot be null? i....

# test

[reik.schatz]

using junit5/assertJ is there a way for the compiler to figure out that something cannot be null? i.e. assertNotNull or assertThat(nullable).isNotNull won’t do the trick

[Lawik]

Why won't assertNotNull do the trick?

[reik.schatz]

not sure, maybe because it’s in a library?

[reik.schatz]

val value: Array<TriggeredOffer>? = response.body()
        assertNotNull(value)
        assertEquals(1, value.size) // doesn't compile

[reik.schatz]

this is what I mean

[robstoll]

AssertJ would need to implement kotlin contracts for that to work. But obviously they don't (as it is a Java library). You could implement your own assertNotNull though doing the contract stuff and delegating to AssertJ

[robstoll]

shameless plug: you could use Atrium instead of AssertJ and write

assert(value?.asList()).notToBeNull {
  hasSize(1)
}

[reik.schatz]

I will certainly check that out @robstoll 🙂

[Mike]

Or write your own function that wraps AssertJ. Either is viable, but from what I’ve seen Atrium is very well done. I haven’t moved from AssertJ (yet), but if I were to move to a Kotlin one, it would be Atrium. Seems the most full-featured Kotlin native assertion library yet.