What is the best way to test abstract class? let’s say I have a class A

abstract class A(param1: Param1, param2: Param2) {
  fun foo() {
    val param1result = param1.get()
    val param2result = param2.get()
    val result = calculateResult(param1result, param2)
  }
  
  abstract fun calculateResult(param1: Param1, param2: Param2): Smth
}

Now, I want to test it. But I can not create an instance of A, since its a abstract class. The only way I managed to make it work is to create a real A class and use spyk function:

class AReal: A {
  override fun calculateResult(...) {
    ...
  }
}

class Test {
  val aReal = spyk(AReal(...., .....))
}

Is there any other better way?

I'm pretty sure you can use a spyk on an abstract class

but u can not call a contructor for abstract class) anymay, i did it loke this:

private val useCase = spyk(UseCaseReal(mockk(), mockk()), recordPrivateCalls = true, block = {
        coEvery { abstartFun(any()) } returns smth
    })

Why do you need to explicitly call the constructor?