When using

kotlin.time.Duration

, this test will pass:

class WorkingSpec : DescribeSpec() {

    init {
        describe("Inline class test") {
            forAll(
                row(1.minutes),
            ) { wrapped: Duration ->
                println(wrapped)
            }
        }
    }
}

while this one will fail:

class FailingSpec : DescribeSpec() {

    init {
        describe("Inline class test") {
            forAll(
                row(1.minutes, true),
            ) { wrapped: Duration, _ ->
                println(wrapped)
            }
        }
    }
}

The only difference is that the failing test uses

row

with two parameters. And the failure is

java.lang.AssertionError: Test failed for (wrapped, 60.0s), (b, true) with error java.lang.ClassCastException: kotlin.time.Duration cannot be cast to java.lang.Number

I kind of expected these would work unless Kotest expected some specific bytecode or used reflection on the parameters there

It does use reflection to work out the param names

Maybe switch to 4.3.0 and use the new data test support ?

before it would just effectively do a forEach over each value testing them one by one

now you actually can see multiple tests created

the old forAll was ok, it would give you a nice error trace

but it wouldn't add individual test cases for you in the output tree

Thanks again! 🙂

This can be misleading because we had no error for nested describe (and an

it

inside it), but in fact no code was really executed for these tests. Seems like either allowing more complex tests inside forall, or crashing if unsupported nesting is found, would be nice

So, for the case when I want to nest `forAll`s (we have a couple), should we use old forAll or move away from data-driven tests completely?

We have tests like

forAll(row(sourceA, sourceB)) { source -> 
  describe("when we do X with $source") {
    forAll(row(fooA, fooB)) { foo ->
      describe("when we do Y with $foo") {
         // more stuff with tests
      }
    }
  }
}