kotlin-logging VS mockito-kotlin

kotlin-logging is a Multiplatform logger for kotlin, whereas SLFK4 is a lightweight wrapper around SLF4J, so it only works on JVM. but if you only need JVM support, SLF4K is very good

We chose kotlin-logging. It is a really convenient library and you can use it like this:

The repo has a ticket open and someone benchmarked the throughput to be +16% inlining the methods or +37% if you inline the classes too. https://github.com/MicroUtils/kotlin-logging/issues/34

Why that over the much more popular kotlin-logging?

As you can see, I create mockUsersRepository object using mock( function. Then, in setup() method, I set up this repository in such a way so that it would return a list of hardcoded values. After this, on top of everything else, I check if, for mockUsersRepository object, getUsers method was called with verify function, in the test method. It’s important to note that Mockito is a very old framework and was originally written for Java. When Kotlin appeared, it turned out that out of the box this framework can work with some limitations, which is why an extension, mockito-kotlin, was released. The example above was written with it. Another Mockito’s limitation was that it was impossible to mock final classes and static methods, and all classes are final by default in Kotlin. Currently, this is solved through mockito-inline but, before, it was a serious limitation. In respect to Java development, there was and is an alternative for Android developers, PowerMock.

In the demo project, I used junit and mockito. One thing we need to pre-learn do the unit test, that is ksp class diagram.

What's wrong with Mockito for Kotlin?

Mockito does not work correctly with Kotlin types out of the box. Spring recommends using Mockk. There is also a special module for Mockito, which adds support for Kotlin - Mockito-Kotlin.