For mocking unit tests, we are currently using the Java library org.mockito:mockito.

In order that the tests for platform-independent application logic can be executed on any supported platform, mockito needs to be replaced as a test dependency.

Mocking library requirements

• multiplatform support for at least Java/Android and iOS

• stable, well-tested and ideally (semi-)official / well-maintained

• support all features of Mockito we are using now

It is possible that when migrating, a bit more effort is necessary because as far as I know, Mockito uses Java reflection to create the mocks, which is a Java specific language feature. In other words, it may not be possible to mock non-interfaces.

Three Kotlin Multiplatform libraries for mocking are known to me, with a few comments from a short look at them, ordered by popularity on github:

Mockative

• seems well maintained
• good documentation
• has a guide how to migrate from Mockito to Mockative and apparently also a similar API to Mockito

MocKMP

• seems well maintained
• good documentation
• backed by a company (Deezer)

MockingBird

• seems well maintained
• from a quick glance, API seems to be a bit inconvenient
• oldest library, i.e. started in 2021, the others in 2022