Test in Kotlin cannot access protected method

Question

I want to test class B:

class B : A {
    override fun init() {
        // do work here
    }
}

class A {
    protected fun init() { } // will be called by internal logic
}

and in Java there is no problem to call: b.init() within test method (test class is in the same package as test subject), but in Kotlin compiler complains:

Cannot access 'init': it is protected in 'B'

@Test
fun `checks init`() {
    val b = B()
    b.init()
    // assert work done
}

Why isn't it working? How can this be workaround (I want to avoid making method public)?

Answer 1

protected in Java is not the same as in Kotlin.

In Java, everything in the same package can access a protected method. See In Java, difference between default, public, protected, and private

In Kotlin, protected means that you can only access it in the same class or any subclass of it. See Visibility Modifiers - Kotlin

The only possible way is to use the internal modifier and make the method visible to your tests in the same module.