JS Union type members should have inherit corresponding marker interface

js/js.libraries/src/generated/org.w3c.dom.kt

@@ -3022,7 +3022,7 @@ native public open class DragEventInit : MouseEventInit() {
     var dataTransfer: DataTransfer?
 }
 
-native public trait Window : EventTarget {
+native public trait Window : EventTarget, UnionMessagePortOrWindow {
     var caches: CacheStorage
         get() = noImpl
         set(value) = noImpl
@@ -3638,20 +3638,20 @@ native public open class MessageEvent(type: String, eventInitDict: MessageEventI
     var lastEventId: String
         get() = noImpl
         set(value) = noImpl
-    var source: dynamic
+    var source: UnionMessagePortOrWindow?
         get() = noImpl
         set(value) = noImpl
     var ports: Array<dynamic>
         get() = noImpl
         set(value) = noImpl
-    fun initMessageEvent(typeArg: String, canBubbleArg: Boolean, cancelableArg: Boolean, dataArg: dynamic, originArg: String, lastEventIdArg: String, sourceArg: dynamic, portsArg: Array<dynamic>): Unit = noImpl
+    fun initMessageEvent(typeArg: String, canBubbleArg: Boolean, cancelableArg: Boolean, dataArg: dynamic, originArg: String, lastEventIdArg: String, sourceArg: UnionMessagePortOrWindow, portsArg: Array<dynamic>): Unit = noImpl
 }
 
 native public open class MessageEventInit : EventInit() {
     var data: dynamic
     var origin: String
     var lastEventId: String
-    var source: dynamic
+    var source: UnionMessagePortOrWindow?
     var ports: Array<MessagePort>
 }
 
@@ -3759,7 +3759,7 @@ native public open class MessageChannel {
         set(value) = noImpl
 }
 
-native public trait MessagePort : EventTarget, Transferable {
+native public trait MessagePort : EventTarget, UnionMessagePortOrWindow, UnionMessagePortOrServiceWorker, UnionClientOrMessagePortOrServiceWorker, Transferable {
     var onmessage: ((Event) -> dynamic)?
         get() = noImpl
         set(value) = noImpl
@@ -4836,6 +4836,9 @@ native public marker trait UnionAudioTrackOrTextTrackOrVideoTrack {
 native public marker trait UnionElementOrMouseEvent {
 }
 
+native public marker trait UnionMessagePortOrWindow {
+}
+
 native public marker trait UnionElementOrProcessingInstruction {
 }
 

libraries/tools/idl2k/src/main/kotlin/gen.kt

@@ -170,7 +170,7 @@ fun generateUnions(ifaces: List<GenerateTraitOrClass>, typedefs: Iterable<Typede
             .filter { it.value.memberTypes.all { type -> type in declaredTypes } }
     val typedefsMarkersMap = typedefsToBeGenerated.groupBy { it.name }.mapValues { mapUnionType(it.value.first().value).copy(name = it.key) }
 
-    val typeNamesToUnions = anonymousUnionTypes.flatMap { unionType -> unionType.memberTypes.map { unionMember -> unionMember to unionType.name } }.toMultiMap() +
+    val typeNamesToUnions = anonymousUnionTypes.flatMap { unionType -> unionType.memberTypes.map { unionMember -> unionMember to unionType.name } }.toMultiMap() merge
             typedefsToBeGenerated.flatMap { typedef -> typedef.value.memberTypes.map { unionMember -> unionMember to typedef.name } }.toMultiMap()
 
     return GenerateUnionTypes(

libraries/tools/idl2k/src/main/kotlin/main.kt

@@ -13,8 +13,6 @@ fun main(args: Array<String>) {
         System.exit(1)
         return
     }
-    outDir.deleteRecursively()
-    outDir.mkdirs()
 
     val repository = srcDir.walkTopDown().filter { it.isDirectory() || it.extension == "idl" }.asSequence().filter { it.isFile() }.fold(Repository(emptyMap(), emptyMap(), emptyMap(), emptyMap())) { acc, e ->
         val fileRepository = parseIDL(ANTLRFileStream(e.getAbsolutePath(), "UTF-8"))
@@ -31,6 +29,9 @@ fun main(args: Array<String>) {
     val unions = generateUnions(definitions, repository.typeDefs.values())
     val allPackages = definitions.map { it.namespace }.distinct().sort()
 
+    outDir.deleteRecursively()
+    outDir.mkdirs()
+
     allPackages.forEach { pkg ->
         File(outDir, pkg + ".kt").bufferedWriter().use { w ->
             w.appendln("/*")

libraries/tools/idl2k/src/main/kotlin/typeMappings.kt

@@ -102,6 +102,7 @@ private fun mapType(repository: Repository, type: String): String =
         type.startsWith("unrestricted") -> mapType(repository, type.substring(12))
         type.startsWith("sequence<") -> "Array<${mapType(repository, type.removePrefix("sequence<").removeSuffix(">").trim())}>"
         type.startsWith("sequence") -> "Array<dynamic>"
+        type.startsWith("Union<") -> "Union<" + splitUnionType(type).map { mapType(repository, it) }.join(",") + ">"
         type in repository.typeDefs -> mapTypedef(repository, type)
         type in repository.enums -> "String"
         type.contains("->") -> {