Thread safety

Mocks created using Mokkery are generally considered "thread safe" in the context of their usage in a multithreaded environment. It means that calling methods on configured mock from different threads is safe.

However, configuration operations (e.g. every, everySuspend) and verification operations (e.g. verify, verifySuspend) are not thread-safe. These operations should be performed from a single thread!

Also, make sure that any defined matcher/answer does not perform any not synchronized side effects. Example below shows this kind of side effect.

var x: Int = 0
every { mock.getAndIncrement() } calls { x++ }

To synchronize it, you can use atomic-fu:

var x = atomic<Int>(0)
every { mock.getAndIncrement() } calls { x.getAndIncrement() }