Seal the protocol factory interface

CHANGELOG.md

@@ -7,7 +7,7 @@ New:
 - Source-based schema parser is now the default. Can be disabled in your schema module with `redwood { useFir = false }`.
 
 Changed:
-- Nothing yet!
+- `ProtocolFactory` interface is now sealed as arbitrary subtypes were never supported. Only schema-generated subtypes should be used.
 
 Fixed:
 - Nothing yet!

redwood-protocol-host/api/redwood-protocol-host.klib.api

@@ -12,11 +12,6 @@ abstract interface <#A: kotlin/Any> app.cash.redwood.protocol.host/GeneratedProt
     abstract fun widgetChildren(app.cash.redwood.protocol/WidgetTag): kotlin.collections/List<app.cash.redwood.protocol/ChildrenTag> // app.cash.redwood.protocol.host/GeneratedProtocolFactory.widgetChildren|widgetChildren(app.cash.redwood.protocol.WidgetTag){}[0]
 }
 
-abstract interface <#A: kotlin/Any> app.cash.redwood.protocol.host/ProtocolFactory { // app.cash.redwood.protocol.host/ProtocolFactory|null[0]
-    abstract val widgetSystem // app.cash.redwood.protocol.host/ProtocolFactory.widgetSystem|{}widgetSystem[0]
-        abstract fun <get-widgetSystem>(): app.cash.redwood.widget/WidgetSystem<#A> // app.cash.redwood.protocol.host/ProtocolFactory.widgetSystem.<get-widgetSystem>|<get-widgetSystem>(){}[0]
-}
-
 abstract interface app.cash.redwood.protocol.host/ProtocolMismatchHandler { // app.cash.redwood.protocol.host/ProtocolMismatchHandler|null[0]
     abstract fun onUnknownChildren(app.cash.redwood.protocol/WidgetTag, app.cash.redwood.protocol/ChildrenTag) // app.cash.redwood.protocol.host/ProtocolMismatchHandler.onUnknownChildren|onUnknownChildren(app.cash.redwood.protocol.WidgetTag;app.cash.redwood.protocol.ChildrenTag){}[0]
     abstract fun onUnknownModifier(app.cash.redwood.protocol/ModifierTag) // app.cash.redwood.protocol.host/ProtocolMismatchHandler.onUnknownModifier|onUnknownModifier(app.cash.redwood.protocol.ModifierTag){}[0]
@@ -29,6 +24,11 @@ abstract interface app.cash.redwood.protocol.host/ProtocolMismatchHandler { // a
     }
 }
 
+sealed interface <#A: kotlin/Any> app.cash.redwood.protocol.host/ProtocolFactory { // app.cash.redwood.protocol.host/ProtocolFactory|null[0]
+    abstract val widgetSystem // app.cash.redwood.protocol.host/ProtocolFactory.widgetSystem|{}widgetSystem[0]
+        abstract fun <get-widgetSystem>(): app.cash.redwood.widget/WidgetSystem<#A> // app.cash.redwood.protocol.host/ProtocolFactory.widgetSystem.<get-widgetSystem>|<get-widgetSystem>(){}[0]
+}
+
 abstract class <#A: kotlin/Any> app.cash.redwood.protocol.host/ProtocolNode { // app.cash.redwood.protocol.host/ProtocolNode|null[0]
     constructor <init>(app.cash.redwood.protocol/Id, app.cash.redwood.protocol/WidgetTag) // app.cash.redwood.protocol.host/ProtocolNode.<init>|<init>(app.cash.redwood.protocol.Id;app.cash.redwood.protocol.WidgetTag){}[0]
 

redwood-protocol-host/src/commonMain/kotlin/app/cash/redwood/protocol/host/ProtocolFactory.kt

@@ -30,7 +30,7 @@ import kotlin.native.ObjCName
  * @see HostProtocolAdapter
  */
 @ObjCName("ProtocolFactory", exact = true)
-public interface ProtocolFactory<W : Any> {
+public sealed interface ProtocolFactory<W : Any> {
   public val widgetSystem: WidgetSystem<W>
 }