Narrowed down property causes compilation failure #335
Description
Consider following code:
interface Result {}
interface SpecifiedResult extends Result {}
export interface SchedulerLike {
now: () => Result;
}
export declare class Scheduler implements SchedulerLike {
now: () => SpecifiedResult;
}as of now it's converted to:
@file:Suppress("INTERFACE_WITH_SUPERCLASS", "OVERRIDING_FINAL_MEMBER", "RETURN_TYPE_MISMATCH_ON_OVERRIDE", "CONFLICTING_OVERLOADS")
import kotlin.js.*
import kotlin.js.Json
import org.khronos.webgl.*
import org.w3c.dom.*
import org.w3c.dom.events.*
import org.w3c.dom.parsing.*
import org.w3c.dom.svg.*
import org.w3c.dom.url.*
import org.w3c.fetch.*
import org.w3c.files.*
import org.w3c.notifications.*
import org.w3c.performance.*
import org.w3c.workers.*
import org.w3c.xhr.*
external interface Result
external interface SpecifiedResult : Result
external interface SchedulerLike {
var now: () -> Result
}
external open class Scheduler : SchedulerLike {
override var now: () -> SpecifiedResult
}Which will fail to compile with:
a/b.module_tmp.kt:27:23: error: type of 'now' doesn't match the type of the overridden var-property 'public abstract var now: () -> Result defined in SchedulerLike'
override var now: () -> SpecifiedResult
Let's discuss what we actually want to do in such case, because as of now I see two options:
#1 replace override var now: () -> SpecifiedResult with just var now: () -> Result
#2 use val
We should actually thoroughly think through all this stuff - right now I'm not sure what would be a better option and even whether we are limited with only these two options.