.

Author: rogeralsing

continue.md

@@ -23,6 +23,7 @@
 - Logical assignment short-circuits skip `PutValue` (including private refs/accessors), and RHS NamedEvaluation now applies to ||=/&&=/??= with identifier LHS, so the logical-assignment cluster (read-only/accessor/non-extensible and name inference) is green.
 - Array index assignments now walk prototype accessors/writable descriptors (including inherited setters) before falling back to element storage, so member-expression for-in targets trigger Array.prototype setters and typed array for-in over resizable buffers enumerates the expected indices.
 - `using` and `await using` declarations still TypeError on non-object initializers but now allow initializer-less for-in/of heads with per-iteration lexical environments, so the TDZ/fresh-binding for-of cases are green.
+- Typed array subclass instances now report their concrete @@toStringTag, generator/async generator functions (and their bound/proxy wrappers) are treated as non-constructors during class heritage resolution, and derived classes extending null leave `this` uninitialized until super, so the class subclass builtins/null-proto/generator superclass cases are green.
 
 ## Next Iteration Plan
 1. Re-run the Language suite to refresh the current failure set after the for-in/of using and array setter fixes.

src/Asynkron.JsEngine/Ast/TypedAstEvaluator.AsyncGeneratorFactory.cs

@@ -218,7 +218,7 @@ public bool TryGetProperty(string name, object? receiver, out object? value)
                                 finalArgs[boundArgs.Count + i] = innerArgs[i];
 
                             return callable.Invoke(finalArgs, boundThis);
-                        }) { DisallowConstruct = true };
+                        }, _realmState, isConstructor: false) { DisallowConstruct = true };
                     });
                     return true;
             }

src/Asynkron.JsEngine/Ast/TypedAstEvaluator.TypedGeneratorFactory.cs

@@ -210,27 +210,27 @@ public bool TryGetProperty(string name, object? receiver, out object? value)
                     value = new HostFunction((_, args) =>
                     {
                         var boundThis = args.GetArgument(0);
-                        var boundArgs = args.SliceFrom(1);
+                    var boundArgs = args.SliceFrom(1);
 
-                        // Generator functions are never constructors, so bound generator functions
-                        // must also have DisallowConstruct = true per ES spec.
-                        return new HostFunction((_, innerArgs) =>
-                        {
-                            if (boundArgs.Count == 0)
-                                return callable.Invoke(innerArgs, boundThis);
-                            if (innerArgs.Count == 0)
-                                return callable.Invoke(boundArgs, boundThis);
-
-                            var finalArgs = new object?[boundArgs.Count + innerArgs.Count];
-                            for (var i = 0; i < boundArgs.Count; i++)
-                                finalArgs[i] = boundArgs[i];
-                            for (var i = 0; i < innerArgs.Count; i++)
-                                finalArgs[boundArgs.Count + i] = innerArgs[i];
-
-                            return callable.Invoke(finalArgs, boundThis);
-                        }) { DisallowConstruct = true };
-                    });
-                    return true;
+                    // Generator functions are never constructors, so bound generator functions
+                    // must also have DisallowConstruct = true per ES spec.
+                    return new HostFunction((_, innerArgs) =>
+                    {
+                        if (boundArgs.Count == 0)
+                            return callable.Invoke(innerArgs, boundThis);
+                        if (innerArgs.Count == 0)
+                            return callable.Invoke(boundArgs, boundThis);
+
+                        var finalArgs = new object?[boundArgs.Count + innerArgs.Count];
+                        for (var i = 0; i < boundArgs.Count; i++)
+                            finalArgs[i] = boundArgs[i];
+                        for (var i = 0; i < innerArgs.Count; i++)
+                            finalArgs[boundArgs.Count + i] = innerArgs[i];
+
+                        return callable.Invoke(finalArgs, boundThis);
+                    }, _realmState, isConstructor: false) { DisallowConstruct = true };
+                });
+                return true;
             }
 
             // Fall back to properties lookup for all other properties

src/Asynkron.JsEngine/JsTypes/HostFunction.cs

@@ -347,13 +347,12 @@ internal static HostFunction CreateBoundFunction(IJsCallable target, object? bou
         {
             var finalArgs = Combine(boundArgs, innerArgs);
             return target.Invoke(finalArgs, boundThis);
-        }, realmState, isConstructor: targetIsConstructor)
+        }, realmState, isConstructor: false)
         {
-            IsBoundFunction = true
+            IsBoundFunction = true,
+            IsConstructor = targetIsConstructor
         };
 
-        boundFunction.PropertiesObject.DeleteOwnProperty("prototype");
-
         boundFunction.SetInvokeWithContext((invokeArgs, _, context, newTarget) =>
         {
             var finalArgs = Combine(boundArgs, invokeArgs);
@@ -424,7 +423,7 @@ private void InitializePrototype()
 
     private void EnsurePrototypeDataProperty()
     {
-        if (!_isConstructor || HasPrototypeDataProperty())
+        if (!_isConstructor || HasPrototypeDataProperty() || IsBoundFunction)
         {
             return;
         }