:kodee-greetings: Hey, I have a very simple quest...

# test

[Ed Holloway-George]

kodee greetings Hey, I have a very simple question that's been driving me a little potty when using Kotlin Test because I have seen some conflicting opinions

```class FakeRepo: Repo {

private val users = mutableSetOf<String>()

fun addUser(name: String) {

users.add(name)

}

fun getUserCount(): Int {

return users.size

}

}

class SomeService(val repo: Repo) {

fun addUser(name: String) {

userRepository.addUser(name)

}

fun getUserCount(): Int {

return userRepository.getUserCount()

}

}```

If you write tests in this form:

```class SomeServiceTest {

private val repo = FakeRepo()

private val sut = SomeService(repo)

@Test

fun test1() {

service.registerUser("Alice")

val result = sut.getUserCount()

assertEquals(1, result)

}

@Test

fun test2() {

service.registerUser("Bob")

service.registerUser("Charlie")

val result = sut.getUserCount()

assertEquals(2, result)

}

}```

Each individual test will pass if it executes first, but wont pass if it's executed after the other. As the order tests are run isn't guaranteed, this is a common cause of issues with fakes that hold state.

Am I right here? The correct approach would be to init sut in a @BeforeTest method right? One of my colleagues mentioned FakeRepo would be recreated every time without @BeforeTest

[dave08]

Did you ever see https://opensavvy.gitlab.io/groundwork/prepared/docs/features/index.html? It should solve quite a few of these problems, and it supports running under Kotlin test https://opensavvy.gitlab.io/groundwork/prepared/docs/tutorials/index.html#__tabbed_1_1

[dave08]

The idea is that prepared values are assured to be reinitialized explicitly on every test. No BeforeXXXs to reset them needed, plus there's quite a few nice features as a plus...

[dave08]

By the way, you could check out your question yourself by putting logs in FakeRepo (or println) and seeing if it's printed for each test or not.

[Ed Holloway-George]

Thanks, but not really looking to introduce a new test framework to solve it. The project is already too well established to shoehorn that in right now.

Back to my og question, I am not sure I am right - it looks like repo and sut are generated every time so I guess this is likely only a problem when Singleton object are used. That seems to go against everything I thought I knew about kotlin tests

[Ed Holloway-George]

Perhaps this is just a best practise when mocking and not when using fakes because of the way mocking frameworks work 🤔

[dave08]

For sure `object`s are only loaded once... same with top-level `val`s....

As for Kotlin Test's behaviour it probably depends on the underlying test runner (junit, junit5...) since all it's annotations are just typealiases to the underlying framework... see: https://github.com/JetBrains/kotlin/blob/2.1.20/libraries/kotlin.test/junit/src/main/kotlin/Annotations.kt

[dave08]

I think junit has a properties file it uses for global configs...