I've got a custom detekt rule with type resolution and I'm receiving the

bindingContext

okay, but

getType

is always

null

. What should I be doing to get the class of the object declaration?

override fun visitObjectDeclaration(declaration: KtObjectDeclaration) {
    super.visitObjectDeclaration(declaration)

    if (bindingContext == BindingContext.EMPTY) return

    if (bindingContext.getType(declaration) is Serializable) {
        report(
            CodeSmell(
                issue = issue,
                entity = Entity.from(declaration),
                message = "Do not use Java Serialization for Kotlin objects."
            )
        )
    }
}

You should be good with:

declaration.superTypeListEntries.any { it.text == "Serializable" }

Hey thanks for that, although I need to check the whole class hierarchy for Serializable, not just if it's a direct super class

I believe you should then use:

bindingContext[BindingContext.CLASS, declaration]?.defaultType

That works almost! It still fails the

is Serializable

check, I think it's a

SimpleTypeImpl

rather than the actual class, or something lazy?

So the

is Serializable

check is most likely a bad approach. I believe you should reach a fully qualified type in some form and then do a string comparison with

java.io.Serializable

. As for the documentation, that’s Kotlin PSI & the compiler API. Really bad documented 😞 That’s a known issue on JetBrains table.

Yeah it's been an absolute slog piecing together clues from around the internet 😂

then I’ll need to recurse up the whole class hierarchy won’t I?

Mmm not really. I believe that with type resolution, you should be able to get all the implemented interfaces, also the one of your superclasses..

I didn't realise it could do that, thanks for the help! Got it working with this

private val KtObjectDeclaration.isJavaSerializable
        get() = bindingContext[BindingContext.CLASS, this]
            ?.defaultType
            ?.supertypes()
            ?.any { it.fqNameOrNull()?.asString() == "java.io.Serializable" } == true

Awesome 🚀