I have a suspending functions that I have mocked, using Mockito but it is returning null
both projects use
\'org.jetbrains.kotlinx:kotlinx-coroutines
Mockito has a special support for suspend functions, but in Kotlin 1.3 there were some changes in how coroutines are implemented internally, so older versions of Mockito are no longer recognize suspend methods compiled by Kotlin 1.3. And kotlinx.coroutines use Kotlin 1.3 since version 1.0.0.
Corresponding support was added to Mockito, but only since version 2.23, so updating your Mockito version will help.