Spring Kotlin - Changed object to class and got error - spring

Question

I changed my code from this:
object SomeHelper{}
to this:
#Component
class SomeHelper(private val anAttribute: AnAttributeService){}
AnAttributeService looks like this:
#Service
class AnAttributeService(private val myLoader: MyLoader){}
This is MyLoader:
interface MyLoader {
fun loadSomething()
}
In my test class I wrote something like this:
class SomeHelperTester{
val cut = SomeHelper
//...
}
which used to work fine when SomeHelper was an object, but now when I write
val cut = SomeHelper(anAttribute = AnAttributeService(myLoader = MyLoader))
MyLoader is red underlined with an error saying Classifier MyLoader does not have a companion object, and thus must be initialized
How can I make this line of code work?

Answer 1

after the myLoader = you need to provide an instance of type MyLoader. you can't just say MyLoader there.
If MyLoader was a class you could have just changed it to MyLoader(). But you defined MyLoader as an interface, which means you need to provide an implementation for it.
The most common way to do it is to make a class that extends the interface and create an instance of that. for example:
class MyLoaderImp: MyLoader {
override fun loadSomething() {
//implementation here
}
}
then you can do
val cut = SomeHelper(anAttribute = AnAttributeService(myLoader = MyLoaderImp()))
also note, in kotlin you don't need to mention the parameter names explicitly unless you provide them in another order or are leaving out some, so this is also valid and shorter
val cut = SomeHelper(AnAttributeService(MyLoaderImp()))
alternatively you can provide an implementation in an anonymous class like this
val cut = SomeHelper(AnAttributeService(object: MyLoader{
override fun loadSomething() {
//implementation here
}
}))
It seems to me that you still lack a lot of the basics about kotlin and programming in general. I suggest you to study some sections of the documentation on kotlin's website to get a better understanding of everything:
https://kotlinlang.org/docs/home.html