is it possible to use a verify block to test if a property was accessed? Specifically I have something like this

class Foo {
    val prop get() = 1
}

val aFoo = Foo()
val myService = MyService(aFoo)
myService.method() // should access Foo::prop
verify {
    aFoo.prop // doesn't work
}

How is the performance state in Mockk? https://github.com/mockk/mockk/issues/13 Any recent performance improvements?

Hey I am getting in this my Unit test

Hey I am testing Live Data value. When I am mocking it giving me null pointer expection.

internal fun handleDataResponse() {
        dataLiveData.postValue(true)
        currentDeviceTypeLiveData.postValue(true)
}

test

@Test
fun `handleDataResponse - Handle connection success `() {
    // STUBBING
    // EXECUTION
    viewModel.handleDataResponse()
    // VERIFICATION
    assertEquals(true, viewModel.dataLiveData.value)
    assertEquals(true, viewModel.currentDeviceTypeLiveData.value)
}

I’m getting a NPE when I use a matcher on a

value class

, is this a known issue?

Hi all. I have a question regarding sequense/order verification. Consider following: Subject:

class Example (val dependency : Dependency, val anotherDependency: AnotherDependency ){
    fun doWork() {
        dependency.doSomething()
        anotherDependency.doSomethingElse()
    }
}


class Dependency() {
    fun doSomething() {
        println("do something")
    }
}

class AnotherDependency() {
    fun doSomethingElse() {
        println("do something")
    }
}

Test Class:

class ExampleTest {
    private val mockDependency = mockk<Dependency>(relaxed = true)
    private val mockAnotherDependency = mockk<AnotherDependency>(relaxed = true)

    val subject = Example(mockDependency, mockAnotherDependency)

    @Test
    fun `when doWork called`() {
        subject.doWork()

        verifyOrder {
            mockDependency.doSomething()
        }
    }
}

My tests are passing even though I never verified that

mockAnotherDependency.doSomethingElse()

invocation. I wonder if there any way to tell mockk to enforce that if any mock object participating in test-case was not verified the test case fails. Without that check I can seamlessly remove:

anotherDependency.doSomethingElse()

from my actual Example.doWork() and tests will still pass.

Hi everyone! I'm having some trouble setting up unit tests for Android in Kotest and MockK. I recently joined a company who already has an android application which did not contain any unit tests. The code is not made with testability in mind so I'm having some trouble. I recently fixed something in a Fragment so I improved the code but I wouldn't call it great. I would like to write tests for it now. Currently I want to test a kotlin function which calls code like this. The other classes are in Java.

ClassWithManyStaticMethods.getSomething().method(lateInitialisedField)

I finally figured out how to mock the static class but stumble upon following error

lateinit property lateInitialisedField has not been initialized

. So the

lateInitialisedField

is a lateinit in the class I want to test. When I call the function I want to test, the

lateInitialisedField

is not initialised. How do I initialise it in the test or prevent the error? The value does not matter for my test, I just want to verify if

method

has been called. I tried using

@InjectMocks

when I create the class under test and created a mockk

lateInitialisedField

in my test but either I'm doing something wrong or this is not the solution. If anyone could point me in the right direction that would be greatly appreciated!

Hello everyone. I'm trying to make use of

verify

- verifying method call with the argument being an object equal to another object comparing field by field but ignoring one or more fields. So far the only reasonable solution I came up with was creating a

matcher

using AssertJ's

usingRecursiveComparison()

and wrapping it to `runCatching`:

inline fun <reified T : Any> MockKVerificationScope.matcherFor(expected: T, vararg ignoredFields: String) = match<T> {
    runCatching {
        assertThat(it).usingRecursiveComparison().ignoringFields(*ignoredFields).isEqualTo(expected)
    }.isSuccess
}

example usage:

verify {
    userRepository.save(matcherFor(expectedUser, "id"))
}

I found the above to be elegant enough from the calling side but was wondering if there would be any more straightforward way to achieve the same with less overhead at the same time. Thanks in advance for any suggestions!

Hello everyone, What do I return when I don't care about the return value? I can't return unit since the return type is

SomeClass

. Do I have to

return SomeClass()

or is there something else available like return any or return whatever?

Hi, in this piece of code, I'm mocking a JDBC

ResultSet

, and therefore its

getLong()

method returns a JVM platform type (i.e. it could be

Long

or

Long?

):

val id: Long? = <...>
every { resultSet.getLong("id") } returns id

Unfortunately, this results in the error message "Type mismatch: inferred type is Long? but Long was expected." Is this a bug, a known limitation, or something I'm doing wrong? I can work around it like this:

every { resultSet.getLong("id") as Long? } returns id

but then IntelliJ IDEA warns me that

as Long?

is unnecessary.

Are there any workarounds to https://github.com/mockk/mockk/issues/791? I’m trying to mock a method call that takes a value class as parameter.

Hello, I have a.

sealed class Either

which either a

Left

or a

Right

But actually no, because in my unit tests, mockk creates a subclass of

Either

which is neither Left nor Right and break the contract of my type Is there a way to forbit mockkk to create a subclass of a sealed class?

hey all - I understand that

inline

functions aren’t mockable (and not spyable from what I can tell?) does anyone have strategies for verifying that calls to a `MutableStateFlow`’s

inline fun <T> MutableStateFlow<T>.update(function: (T) -> T)

is invoked with the correct argument (or invoked at all)?

I have an object, how can I spy and verify its private calls?

Hey folks, I've got an intermittently failing mockk issue that I'm curious if anybody else has ever dealt with. We have a metrics interface with a

timed()

function that I'm trying to mock:

interface Metrics {
    suspend fun <T> timed(name: String, f: suspend () -> T): T
}

So you would think you could mock that with:

val mockMetrics: Metrics = mockk()
val funSlot = slot<suspend () -> Either<Nothing, Transfer>>()
coEvery { mockMetrics.timed(any(), capture(funSlot)) } coAnswers { funSlot.captured() }
mockMetrics.timed("metricName") { foo() }

That is only sometimes correct, which is the worst kind of correct. Depending on how I run the tests (kotest tests running on gradle), the test containing this mock will pass sometimes. When it fails, we get a

io.mockk.MockKException: no answer found for: Metrics(#3).timed(mmp.process.transfer.latency, continuation {}, continuation {})

which implies that

timed

takes three arguments. I believe that's expected behavior, based on how suspend functions compile behind the scenes. But that also implies that our installed answer on our mocked

timed

call complied differently -- but only sometimes. Has anyone dealt with behavior like this before? My current workaround is just writing a custom little MockMetrics class instead of using mockk for it.

Hey how can one mock a static method that has overloads? I’m trying to mock and it’s giving me the ambiguity error

Also do I need to explicitly call

unmockkStatic

or

clearStaticMockk

after done using the static mock?

hi anyone knows the equivalente of

on

on Mockito but in MockK? I need to change the response type of an

every

call but I found no operator to do this as with the

on

operator in Mockito

I have a function with many overloads:

fun prepareStatement(sql: String): PreparedStatement
fun prepareStatement(sql: String, resultSetType: Int): PreparedStatement
fun prepareStatement(sql: String, resultSetType: Int, resultSetConcurrency: Int): PreparedStatement
fun prepareStatement(sql: String, resultSetType: Int, resultSetConcurrency: Int, resultSetHoldability: Int): PreparedStatement

What if I want to mock all of them in the same way, whereas I only care about the `sql`parameter? Currently I repeat

every  {

block for each overload. Is there more preferred way, e.g. matching functions by name?

Hi guys 🙂 Is there anyway to make the second mock declaration work?

class DummyUseCase {

    operator fun invoke(): String = TODO()
}

@Test
fun test() {
    val dummyUseCase1: DummyUseCase = mockk()
    every { dummyUseCase1.invoke() } returns ""
    val dummyUseCase2: DummyUseCase = mockk {
        every { this.invoke() } returns ""
    }
}

In the second case, I have a compilation error: “Not enough information to infer type variable T” (I’m fine with the first declaration but we’ve been trying this

operator invoke

thing for our use cases that was showcased in one of the recent MAD Skills video and we use sometimes the second mock declaration) Thanks! 🙂

Hello guys, I have this exemple the DictKey.get will call and external api, then I’m trying to mock

DictKey.get call, but I'm having this problem Type mismatch: inferred type is DictKey but MockKMatcherScope.DynamicCall was expected

class A {
   fun callExternalApi(key: String) {
      return DictKey.get(key) 
   }
}

But DictKey.get return an instance Of DictKey(….) I would like to stub it What I’m doing..

val key = "my-key"
val mockDt = mockk<DictKey>()
every { mockDt.get(key) } returns what I have to put here?
val retruanCallExternalApi = A().callExternalApi(key)

Hello, how do I effectively mockk a value class?

Hello, I have this function

fun <T> dummy(arg: Int, argTwo: T) {
  //do something with argTwo
}

I tried to mock with

mockkStatic(::dummy)

but it said not enough information to infer T, so does anyone knows how can I solve it?

EDIT: I solved this I’m writing a test for a class handling a 3rd party analytics library. The class under test needs to handler an

Analytics

object, but unfortunately

mockk<Analytics>()

cannot create a mock because of a static android Handler in that class:

public class Analytics { // this is 3rd party code I can't change

  static final Handler HANDLER =
      new Handler(Looper.getMainLooper()) {
        @Override
        public void handleMessage(Message msg) {
          throw new AssertionError("Unknown handler message received: " + msg.what);
        }
      };
// rest of class here
}

I tried using both

mockk<Analytics>()

and adding

mockkConstructor(Handler::class)

but that didn’t work. Any suggestions?

Hey I’m getting an error when trying to mock a KMongo

CoroutineCollection

with the following code

data class User(val id: Int, val name: String)

class Service(private val myDatabase: CoroutineDatabase) {
    private val userCollection: CoroutineCollection<User> = myDatabase.getCollection("users")
    suspend fun getById(id: Int): User? = userCollection.findOneById(id)
    // ...
    suspend fun insertUser(user: User): InsertOneResult = userCollection.insertOne(user)
}

@Test
fun myTest(): Unit = runBlocking {
    // Arrange
    val database = mockk<CoroutineDatabase>()
    val userCol = mockk<CoroutineCollection<User>>()

    every {
        database.getCollection<User>("users")
    } returns userCol


    val service = Service(database)
    val expectedUser = User(30, "Joe")

    coEvery {
        userCol.findOneById(30)
    } returns expectedUser


    // Act
    val actualUser = service.getById(30)

    // Assert
    assertEquals(expectedUser, actualUser)
}

The error is

class org.litote.kmongo.coroutine.CoroutineCollection cannot be cast to class com.mongodb.reactivestreams.client.MongoCollection (org.litote.kmongo.coroutine.CoroutineCollection and com.mongodb.reactivestreams.client.MongoCollection are in unnamed module of loader 'app')

I suspect this is due to functions like

CoroutineDatabase::getCollection<T>(String)

being inline

hey! this question remained unanswered a couple of years ago and now I find myself wondering the same. Let’s see if this time I succeed 🙂 Can someone help me here?

Hey I’m having issues mocking an extension property, how can one do it? Suppose I have

class MyService { … }

and an extension property like

val MyService.myProp: String
    get() = "value"

when doing

mockk<MyService> {
    every { myProp } returns "otherValue"
}

it throws a

MockkException

msg:

Missing mocked calls inside every { ... } block: make sure the object inside the block is a mock

Hello, I have a mocked object and trying to setup

coEvery

to mock a specific function although somehow the

coEvery

call is hanging when I run the test. What can cause this hanging?

Hello, the code in the thread gives a warning. Is this intended behaviour or am I abusing Mockk?

Can someone help me with the problem I keep facing with value classes? I have a simple class that holds multiple fields, but one of the is the "Duration" value class of kotlin. when I try to mockk it, (v1.12.2) I keep getting classcastexceptions from Long to Duration

every { someClass.duration } returns 30.minutes

I can't run this