Alternative lateinit implementation without using the native lateinit Kotlin declaration.

001 - Kotlin lateinit.kt

class MyTest {
    lateinit var subject: TestSubject

    @SetUp fun setup() {
        subject = TestSubject()
    }

    @Test fun test() {
        subject.method()  // dereference directly
    }
}

002 - LateInit.kt

class LateInit<T>() {
    
    private var value: T? = null
    
    fun set(_value: T) {
        value = _value
    }
    
    fun get(): T {
        return value ?: throw UninitializedPropertyAccessException()
    }
}

003 - usage.kt

// declaration
val user = LateInit<User>()

// cannot use it before initialisation
user.get() // UninitializedPropertyAccessException

fun onCreate() {

    // initialisation
    user.set(User(name = "Marco"))
    
    // now you can safely use it
    user.get()
}