Configurable factory in Kotlin for JavaScript - kotlin

Question

I have a Kolin class A whose property is either supplied in a primary constructor, or is created by a factory in the secondary constructor of A.
interface I
class O : I
class A (val i: I) {
constructor(): this(factory!!.create())
}
interface Factory {
fun create(): I
}
class MyFactory: Factory {
override fun create(): I {
return O()
}
}
var factory: Factory? = null
fun main(args: Array<String>) {
factory = MyFactory()
A()
}
When I compile this code to JavaScript (Kolin Compiler version 1.0.6-release-127) and run it in a browser (Safari 10.0.3), I get the following runtime error:
ReferenceError:Can't find variable: tmp$0
The error occurs in the secondary constructor of A. It seems that Kolin has a problem in performing the null check of a parameter in the secondary constructor. The code runs correctly when I change the factory declaration to "not null" and remove the factory initialization from the main() method:
val factory: Factory = MyFactory()
fun main(args: Array<String>) {
A()
}
But this is not what I want, since I want to be able to configure the factory at application startup time.
Do I miss something, or is this a bug in Kotlin's JavaScript compiler? Does anybody know a workaround for this problem? Is there another or better way to design configurable factories in Kotlin for JavaScript?
Generated JavaScript code:
var KotlinTest = function (Kotlin) {
'use strict';
var _ = Kotlin.defineRootPackage(function () {
this.factory = null;
}, /** #lends _ */ {
I: Kotlin.createTrait(null),
O: Kotlin.createClass(function () {
return [_.I];
}, function O() {
}),
A: Kotlin.createClass(null, function A(i) {
this.i = i;
}),
A_init: function ($this) {
$this = $this || Object.create(_.A.prototype);
_.A.call($this, ((tmp$0 = _.factory) != null ? tmp$0 : Kotlin.throwNPE()).create());
return $this;
},
Factory: Kotlin.createTrait(null),
MyFactory: Kotlin.createClass(function () {
return [_.Factory];
}, function MyFactory() {
}, /** #lends _.MyFactory.prototype */ {
create: function () {
return new _.O();
}
}),
main_kand9s$: function (args) {
_.factory = new _.MyFactory();
_.A_init();
}
});
Kotlin.defineModule('KotlinTest', _);
_.main_kand9s$([]);
return _;
}(kotlin);

Answer 1

Answering my own question. As #marstran correctly commented, this seems to be a bug in Kolin's Javascript compiler 1.0.6 which seems to be fixed in 1.1-beta. In the meantime, I'm using a workaround similar to the following:
interface I
class O : I
class A (val i: I) {
constructor(): this(Factory.get().create())
}
interface Factory {
companion object {
private var IMPL : Factory? = null
fun get(): Factory = IMPL!!
fun set(impl: Factory) {
IMPL = impl
}
}
fun create(): I
}
class MyFactory: Factory {
override fun create(): I {
return O()
}
}
fun main(args: Array<String>) {
Factory.set(MyFactory())
A()
}