If you add this file in proper place and run tests again, class Repository will be properly mocked and error Mockito cannot mock/spy because your class is final class will be there no more. With contents: mock-maker-inline content MockMaker location in project files In app/src/test/resources/mockito-extensions add file:

kotlin unit-testing mockito Share Follow asked 2 mins ago Jeffrey Blattman 22.

To enable mocking final classes, configure MockMaker: Configure MockMaker Note I'm using this custom any function: private fun any (type: Class): T Mockito.any (type) To work around the 'any is null' problem when using Mockito with Kotlin.

While the preferred solution is to use an interface for dependency, there is solution that will allow us to mock final classes with Mockito.

Mocking frameworks usually extend your class to do something with implementation details.

Classes in Kotlin are 'final' unless specified otherwise (open class, abstract class).

Kotlin default modifier translates to 'final' in Java.

Classes marked as 'final' should not be extended.Let's consider the following system under test: class Repository if you are unsure how to use Mockito with Kotlin, check Īfter running this test it is likely that you will encounter the following error: Cannot mock/spy class

Mockito kotlin