Backing property requires other value to be part of public API

[paul-dingemans]

According to Kotlin Coding conventions:

If a class has two properties which are conceptually the same but one is part of a public API and another is an implementation detail, use an underscore as the prefix for the name of the private property:

Currently it is not checked that the variable not starting with _ is a part of the public API. As a result the _elementList property is code below is not reported:

            class Foo {
                private val _elementList = mutableListOf<Element>()

                private val elementList: List<Element>
                    get() = _elementList
            }

[Goooler]

We can ignore this elementList if it's public or internal?

[paul-dingemans]

We can ignore this elementList if it's public or internal?

I am not sure whether I understand your question. As I read the documentation, a backing property requires a private property of which the name starts with _ and a public property with same name but not starting with _.

[Goooler]

Yes, I meant if an internal property with same name but not starting with _, should we also ignore this case?

Example:

class Foo {
  private val _foo = "foo"

  internal val foo: String get() = _foo
}

And maybe there is another case like:

class Foo {
  internal val _foo = "foo"

  val foo: String get() = _foo
}

Should we consider bypassing this?

[paul-dingemans]

If we go this route, more exceptions will follow. The end result will be that properties can always start with an _. I think we should as close to the coding conventions as is possible. We can consider to split this rule and move cheking of the backing property to a separate rule, which then can be disabled if a project uses backing properties less strict than the coding conventions.