Hey folks, what are the differences between Kotest and Spek?

I believe this code works correctly. In that case, maybe it's something to add in the lib? If there is a better way, or if there is a bug, which one?

open class FlatmapCombinedShrinker2<Original, value1, value2>(
    private val select1: (Original) -> value1,
    private val shrinker1: Shrinker<value1>,
    private val select2: (Original) -> value2,
    private val shrinker2: Shrinker<value2>,
    private val composer: Original.(value1, value2) -> Original
) : Shrinker<Original> {
    override fun shrink(value: Original): List<Original> {
        val hasShrinks = BooleanArray(2) { true }

        val value1 = select1(value)
        val shrinks1 = shrinker1.shrink(value1).ifEmpty {
            hasShrinks[0] = false
            listOf(value1)
        }

        val value2 = select2(value)
        val shrinks2 = shrinker2.shrink(value2).ifEmpty {
            hasShrinks[1] = false
            listOf(value2)
        }

        return if (hasShrinks.any { it }) {
            shrinks1.flatMap { val1 ->
                shrinks2.map { val2 ->
                    value.composer(val1, val2)
                }
            }
        } else emptyList()
    }
}

Hey 🙂 I’m currently fiddling around with

property-based-testing

in Kotest. I want to create a custom

arbitrary

based on already defined

arbitraries

. I found this page in the documentation about it: https://kotest.io/docs/proptest/custom-generators.html#arbitrary In the documentation there is a code snippet about doing it:

val personArb = arbitrary { rs ->
   val names = Arb.string().values(rs)
   val ages = <http://Arb.int|Arb.int>().values(rs)
   names.zip(ages).map { (name, age) -> Person(name.value, age.value) }
}

The concept is clear, but the function

values(RandomSource)

is deprecated. What am I supposed to use as an alternative in this case? Would it be

generate(RandomSource)

? The replacement description is not really applicable for this particular case I think. Using

samples(RandomSource)

seems wrong, because I think it makes sense to keep the edge-cases of the arbs here 🤔 .

Using

4.3.1

, and notice that when running tests in maven and one fails, I only get the string from the bottom-most

should

in the report, which makes it ambiguous. Is there a way to get the entire test "path" string to show up there? I.e. the stuff from the surrounding

context

blocks?

I'm running into an issue where I'm using

runBlockingTest

and

advanceUntilIdle

and I think it's fooling kotest into thinking the test has timed out

Is it just my internet connection, or is kotest.io site just VERY slow (maybe because of popularity 🙂)?

what right click menu are you using? I’m using IDEA and not AS, but if i select run from the project explorer context menu it asks me what test runner i want to use.

Added the plugin, but running individual tests using a gutter icon doesn’t work. It shows the test passes without running anything. Is there something wrong with my setup? Happy to provide additional details.

Seems like this issue went stale after implementing Robolectric support, so it's not too clear...: https://github.com/kotest/kotest/issues/189

Lol indeed. You should revert to the previous version for now

In property based tests, when I set

kotest.proptest.default.iteration.count

to something low, e.g.

1

, plenty of my tests fails because

computeDefaultIteration

provides

1

for arbs with edgecases where

minIterations > 1

. Is this a bug or there's logic behind this? Right now

computeDefaultIteration

explicitly supports only

Exhaustive

https://github.com/kotest/kotest/blob/master/kotest-property/src/commonMain/kotlin/io/kotest/property/config.kt#L17

Separate question - shouldn't

minIterations

for

Arb

include at least one sample? Right now it counts only all edge cases https://github.com/kotest/kotest/blob/master/kotest-property/src/commonMain/kotlin/io/kotest/property/Gen.kt#L39

If I spin up a Spec with the

@SpringBootTest

annotation, can I get access to the app context within a specific test? I’m trying to migrate some tests that look like this:

contextRunner.run { context ->
   assertThat(context)
      .hasSingleBean(MongoCustomConversions::class.java)
}

and change properties on the context for a test?

contextRunner
    .withPropertyValues("spring.data.mongodb.migrations.enabled:false")
    .run { context ->
        assertThat(context)
            .doesNotHaveBean(Mongobee::class.java)
    }

4.4.0.RC1 is being released. Would welcome any feedback and bug reports

Hi, Big fan of Kotest! Thanks for this amazing library. Newbie property testing question: I'm trying to compose an object with

Arb.bind()

, the object contains a list of other objects. I'm having trouble generating a list of objects to populate my main arb with.. Here's what I have

class CartModelTest : StringSpec({
    "create Cart from CartEntity" {
        val cartItemArb: Arb<CartLineItemEntity> = Arb.bind(
            Arb.string(),
            <http://Arb.int|Arb.int>(1..999)
        ) { randomItemId, randomQuantity ->
            CartLineItemEntityBuilder()
                .itemId(randomItemId)
                .quantity(randomQuantity)
                .build()

        }
        val cartEntityArb: Arb<CartEntity> = Arb.bind(
            Arb.string(),
            Arb.double(),
            <http://Arb.int|Arb.int>()
        ) { randomId, randomAmount, randomItemCount ->
            val amount = AmountBuilder().value(randomAmount).build()
            CartEntityBuilder()
                .cartId(randomId)
                .grandTotal(amount)
                .subtotal(amount)
                .totalDiscount(amount)
                .numberOfItems(randomItemCount)
                    //TODO how do i create a random list of CartLineItems?
                .itemList(listOf(cartItemArb.single()))
                .build()
        }
        checkAll(cartEntityArb) { cartEntity ->
            val result = Cart.fromCartEntity(cartEntity)
            result.workfile shouldBe cartEntity.cartId
        }
    }
})

How do I populate itemList in my

cartEntityArb

with a list of

cartItemArbs

?

Should this work for overriding which tests are run by gradle when I run

./gradlew test

?

test.doFirst {
    System.setProperty("kotest.tags", "Unit")
}

Is there a way to run a single test from the command line if a test framework is used?

Question on the output of test failures. The stack traces I get are pretty much useless sometimes. Is there something I'm doing incorrect? Will post in thread

I’m trying to convert some tests from straight jUnit and need a bit of help. I have this

fun <T> assertValidation(o: Any, validation: Class<T>, propertyName: String? = null) {

        val violations = when (propertyName) {
            null -> validator.validate(o)
            else -> validator.validateProperty(o, propertyName)
        }

        assertAll(
            Executable {
                assertEquals(
                    1,
                    violations.count(),
                    "Expecting one violation, received ${violations.count()}"
                )
            },
            Executable {
                violations.forEach { violation ->
                    val annotation = violation.constraintDescriptor.annotation
                    assertThat(annotation, instanceOf(validation))
                }
            }
        )

I’m trying to convert the type assertion to use ShouldBeInstanceOf<t> but the compiler doesn’t like it because its a generic type. I’m trying to change it to something along the lines of

inline fun <reified T> assertValidation(o: Any, validation: Class<T>, propertyName: String? = null) {
        val violations = when (propertyName) {
            null -> validator.validate(o)
            else -> validator.validateProperty(o, propertyName)
        }

        assertSoftly {
            withClue("Expecting one violation, received ${violations.count()}") {
                violations.shouldHaveSize(1)
            }
            violations.forEach { violation ->
                val annotation = violation.constraintDescriptor.annotation
                annotation.shouldBeInstanceOf<validation>()
                //assertThat(annotation, instanceOf(validation))
            }
        }
    }

How can I use ShouldBeInstanceOf in this case?

Is the 4.4.0.RC1 expected to work with Kotest plugin? I am getting "Test framework quit unexpectedly" from IntelliJ. after the upgrade when I run the tests as Kotest (with the plugin).

Hello! Can anyone give me a clue why 

StringSpecScope

 doesn’t implement 

ContainerScope

? It appeared that I can’t use

io.kotest.core.datatest.forAll

inside

StringSpec

(or I haven’t found a way…)

Hello! I’m new here. Great work with

kotest

and thank you for all the work! I have a question, if anyone is available to answer it: I want to generate HTML reports from XML reports (built with Junit XML listener), with Gradle. I can’t seem to find a way to do it without any extra Gradle plugin. Is anyone aware of a listener (similar to what JUnit XML) that will allow me to run this after executing the entire

kotest

test suite? Thank you!

Does assertion library support JS-IR?

Can something like “Rule” be used in kotest? I need to set the MainCoroutineRule.

Hi. I’m trying to use Kotest with Robolectric on android local test but I’m getting this error as soon as i run my test:

java.lang.IllegalArgumentException: failed to configure io.kotest.extensions.robolectric.ContainedRobolectricRunner$PlaceholderTest.testPlaceholder: Package targetSdkVersion=30 > maxSdkVersion=29
	at org.robolectric.RobolectricTestRunner.getChildren(RobolectricTestRunner.java:254)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner.access$getChildren(ContainedRobolectricRunner.kt:7)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner$placeHolderMethod$2.invoke(ContainedRobolectricRunner.kt:10)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner$placeHolderMethod$2.invoke(ContainedRobolectricRunner.kt:7)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner.getPlaceHolderMethod(ContainedRobolectricRunner.kt)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner.access$getPlaceHolderMethod$p(ContainedRobolectricRunner.kt:7)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner$sdkEnvironment$2.invoke(ContainedRobolectricRunner.kt:19)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner$sdkEnvironment$2.invoke(ContainedRobolectricRunner.kt:7)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at io.kotest.extensions.robolectric.ContainedRobolectricRunner.getSdkEnvironment(ContainedRobolectricRunner.kt)
	at io.kotest.extensions.robolectric.RobolectricExtension.instantiate(RobolectricExtension.kt:16)
	at io.kotest.engine.InstantiateSpecKt.createAndInitializeSpec(instantiateSpec.kt:21)
	at io.kotest.engine.spec.SpecExecutor.createInstance(SpecExecutor.kt:103)
	at io.kotest.engine.spec.SpecExecutor.execute(SpecExecutor.kt:43)
	at io.kotest.engine.KotestEngine$submitBatch$$inlined$forEach$lambda$1$1.invokeSuspend(KotestEngine.kt:139)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:241)
	at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:270)
	at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:79)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:54)
	at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:36)
	at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
	at io.kotest.engine.KotestEngine$submitBatch$$inlined$forEach$lambda$1.run(KotestEngine.kt:138)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

test code is here:

@RobolectricTest
@Config(sdk = [Build.VERSION_CODES.P])
class ExampleUnitTest: FunSpec ({
    test("test") {
        "aa" shouldBe "aa"
    }
})

How can i fix it?

hi. I’ve got a weird mockk behaviour if I’m using

relaxed=true

. my env is kotlin, mockk and kotest .

relaxed - allows creation with no specific behaviour

in my case I expect an unspecified SimpleDataClass, something like

SimpleDataClass(a = null)

. In debug mode I can see that

a = null

but

if( a != null)

is true. I created a litte playground https://github.com/cryptoki/kotest-mockk-relaxed The picture shows the debugger output. Any ideas why the behaviour is like that? With

relaxed=true

there is a big space for mistakes if I’m bit lazy with my test. thanks.

HI, I’m trying to use kotest for the 1st time as it looks very promising. However, with the following test

package com.bethesomm.firebase.auth

import io.kotest.core.spec.style.FunSpec
import io.kotest.matchers.ints.shouldBeExactly


class FirebaseUserTest : FunSpec({

    test("should do whatever") {
        "hello".length shouldBeExactly 5
    }
})

I have the following error message

[java.lang.ClassNotFoundException: com.bethesomm.firebase.auth.FirebaseUserTest]

Did I miss something? FYI, I’m using the version 4.4.0.RC2

Ok I made it work after restarting the IDE 😞 However, IO don’t know if that’s expected but when I run my tests through gradle, only the test written with kotest are recognized, all the other ones, written with Junit 5, are ignored. Is it an expected behavior?

All my issues above have been quickly fixed so I’m hoping for this last one to be as quick to solve 🙂 The last problem, I’m facing is whenever I change a test or add a test in Android Studio, the runner runs the test as if they didnt change. I have to rebuild the module everytime for the change to have an effect. Is there a specific configuration or a plugin besides the intelliJ one that I should add to make things work mor smoothly? FYI im on AS 4.2 beta3 and writing my tests in a multiplatform module