How to get the resolved type of property getter us...

# k2-adopters

[Atul Gupta]

How to get the resolved type of property getter using delegate using analyze apis?
Earlier using bindingContext below code was working

val property = this?.parent as? KtProperty ?: return false
val propertyDescriptor =
    bindingContext[BindingContext.DECLARATION_TO_DESCRIPTOR, property] as? PropertyDescriptor
return propertyDescriptor?.getter?.let {
    bindingContext[BindingContext.DELEGATED_PROPERTY_RESOLVED_CALL, it]
        ?.resultingDescriptor
        ?.returnType

closest I could get is below

val delegate = this ?: return true
return analyze(delegate) {
    val functionSymbol = delegate
        .mainReference
        ?.resolveToSymbols()
        ?.filterIsInstance<KaFunctionSymbol>()
        ?.firstOrNull {
            it.callableId?.callableName == OperatorNameConventions.GET_VALUE
        }
    functionSymbol?.returnType?.nullability == KaTypeNullability.NULLABLE

but this gives the type of the actual implementation not the runtime resolved type(few examples in the 🧵)

[Atul Gupta]

// example 1
class A {
    val a: Int? by lazy {
        5
    }
}
// using bindingContext it returns `Int`
// using analyze api it returns `V`(this is generic type by which lazy is implemented not the actual type)

// example 2
class A(private var aDelegate: Int?) {
    private var a: Int? by this::aDelegate
}
// using bindingContext it returns `Int?`
// using the analyze api it returns `V`

[Atul Gupta]

In short is there any equivalent of BindingContext.DELEGATED_PROPERTY_RESOLVED_CALL in analyze api

[Roman Golyshev]

Hi! If I understand your request correctly, there’s no way to do what you want with Analysis API at the moment

You would have to wait for KT-66039 to address those issues

[Roman Golyshev]

Let me ask you this: why exactly do you need to know the type of the getter of the delegated property? Are you talking about getValue operator specifically?

Wouldn’t it be enough to simply know the type of the property itself in that case?

[Atul Gupta]

Hi Thanks for the answer!
I was working on migrating(PR) the Detekt rule CanBeNonNullable
It warns you for some property which is declared as nullable(maybe by mistake) but can be declared as non null

For this usecase, I need to know the type of getter body of delegated property.

In my migration PR I was able to pass all the TCs except the above mentioned cases