LibJS: Convert internal_define_own_property() to ThrowCompletionOr

Meta/Lagom/Tools/CodeGenerators/LibWeb/WrapperGenerator.cpp

@@ -1417,7 +1417,7 @@ public:
         generator.append(R"~~~(
     virtual JS::ThrowCompletionOr<Optional<JS::PropertyDescriptor>> internal_get_own_property(JS::PropertyName const&) const override;
     virtual bool internal_set(JS::PropertyName const&, JS::Value, JS::Value) override;
-    virtual bool internal_define_own_property(JS::PropertyName const&, JS::PropertyDescriptor const&) override;
+    virtual JS::ThrowCompletionOr<bool> internal_define_own_property(JS::PropertyName const&, JS::PropertyDescriptor const&) override;
     virtual bool internal_delete(JS::PropertyName const&) override;
     virtual JS::ThrowCompletionOr<bool> internal_prevent_extensions() override;
     virtual JS::MarkedValueList internal_own_property_keys() const override;
@@ -2051,7 +2051,7 @@ bool @class_name@::internal_set(JS::PropertyName const& property_name, JS::Value
 
         // 3.9.3. [[DefineOwnProperty]], https://heycam.github.io/webidl/#legacy-platform-object-defineownproperty
         scoped_generator.append(R"~~~(
-bool @class_name@::internal_define_own_property(JS::PropertyName const& property_name, JS::PropertyDescriptor const& property_descriptor)
+JS::ThrowCompletionOr<bool> @class_name@::internal_define_own_property(JS::PropertyName const& property_name, JS::PropertyDescriptor const& property_descriptor)
 {
     [[maybe_unused]] auto& vm = this->vm();
     auto& global_object = this->global_object();
@@ -2076,8 +2076,8 @@ bool @class_name@::internal_define_own_property(JS::PropertyName const& property
                 scoped_generator.append(R"~~~(
         // 3. Invoke the indexed property setter on O with P and Desc.[[Value]].
         invoke_indexed_property_setter(global_object, impl(), property_name, *property_descriptor.value);
-        if (vm.exception())
+        if (auto* exception = vm.exception())
-            return {};
+            return JS::throw_completion(exception->value());
 
         // 4. Return true.
         return true;
@@ -2110,7 +2110,7 @@ bool @class_name@::internal_define_own_property(JS::PropertyName const& property
             if (!interface.extended_attributes.contains("LegacyOverrideBuiltIns")) {
                 scoped_generator.append(R"~~~(
         // NOTE: This has to be done manually instead of using Object::has_own_property, as that would use the overrided internal_get_own_property.
-        auto own_property_named_p = TRY_OR_DISCARD(Object::internal_get_own_property(property_name));
+        auto own_property_named_p = TRY(Object::internal_get_own_property(property_name));
 
         if (!own_property_named_p.has_value()))~~~");
             }
@@ -2135,8 +2135,8 @@ bool @class_name@::internal_define_own_property(JS::PropertyName const& property
 
             // 2. Invoke the named property setter on O with P and Desc.[[Value]].
             invoke_named_property_setter(global_object, impl(), property_name_as_string, *property_descriptor.value);
-            if (vm.exception())
+            if (auto* exception = vm.exception())
-                return {};
+                return JS::throw_completion(exception->value());
 
             // 3. Return true.
             return true;

Userland/Libraries/LibJS/Runtime/ArgumentsObject.cpp

@@ -123,7 +123,7 @@ ThrowCompletionOr<Optional<PropertyDescriptor>> ArgumentsObject::internal_get_ow
 }
 
 // 10.4.4.2 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-arguments-exotic-objects-defineownproperty-p-desc
-bool ArgumentsObject::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& descriptor)
+ThrowCompletionOr<bool> ArgumentsObject::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& descriptor)
 {
     // 1. Let map be args.[[ParameterMap]].
     auto& map = parameter_map();
@@ -146,9 +146,7 @@ bool ArgumentsObject::internal_define_own_property(PropertyName const& property_
     }
 
     // 5. Let allowed be ? OrdinaryDefineOwnProperty(args, P, newArgDesc).
-    bool allowed = Object::internal_define_own_property(property_name, new_arg_desc);
+    bool allowed = TRY(Object::internal_define_own_property(property_name, new_arg_desc));
-    if (vm().exception())
-        return false;
 
     // 6. If allowed is false, return false.
     if (!allowed)

Userland/Libraries/LibJS/Runtime/ArgumentsObject.h

@@ -24,7 +24,7 @@ public:
     Environment& environment() { return m_environment; }
 
     virtual ThrowCompletionOr<Optional<PropertyDescriptor>> internal_get_own_property(PropertyName const&) const override;
-    virtual bool internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
+    virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
     virtual Value internal_get(PropertyName const&, Value receiver) const override;
     virtual bool internal_set(PropertyName const&, Value value, Value receiver) override;
     virtual bool internal_delete(PropertyName const&) override;

Userland/Libraries/LibJS/Runtime/Array.cpp

@@ -24,7 +24,7 @@ Array* Array::create(GlobalObject& global_object, size_t length, Object* prototy
     if (!prototype)
         prototype = global_object.array_prototype();
     auto* array = global_object.heap().allocate<Array>(global_object, *prototype);
-    array->internal_define_own_property(vm.names.length, { .value = Value(length), .writable = true, .enumerable = false, .configurable = false });
+    (void)array->internal_define_own_property(vm.names.length, { .value = Value(length), .writable = true, .enumerable = false, .configurable = false });
     return array;
 }
 
@@ -168,7 +168,7 @@ ThrowCompletionOr<Optional<PropertyDescriptor>> Array::internal_get_own_property
 }
 
 // 10.4.2.1 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-array-exotic-objects-defineownproperty-p-desc
-bool Array::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
+ThrowCompletionOr<bool> Array::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
 {
     auto& vm = this->vm();
 
@@ -178,7 +178,10 @@ bool Array::internal_define_own_property(PropertyName const& property_name, Prop
     // 2. If P is "length", then
     if (property_name.is_string() && property_name.as_string() == vm.names.length.as_string()) {
         // a. Return ? ArraySetLength(A, Desc).
-        return set_length(property_descriptor);
+        auto success = set_length(property_descriptor);
+        if (auto* exception = vm.exception())
+            return throw_completion(exception->value());
+        return success;
     }
 
     // 3. Else if P is an array index, then
@@ -195,7 +198,7 @@ bool Array::internal_define_own_property(PropertyName const& property_name, Prop
             return false;
 
         // h. Let succeeded be ! OrdinaryDefineOwnProperty(A, P, Desc).
-        auto succeeded = Object::internal_define_own_property(property_name, property_descriptor);
+        auto succeeded = Object::internal_define_own_property(property_name, property_descriptor).release_value();
         // i. If succeeded is false, return false.
         if (!succeeded)
             return false;

Userland/Libraries/LibJS/Runtime/Array.h

@@ -39,7 +39,7 @@ public:
     virtual ~Array() override;
 
     virtual ThrowCompletionOr<Optional<PropertyDescriptor>> internal_get_own_property(PropertyName const&) const override;
-    virtual bool internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
+    virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
     virtual bool internal_delete(PropertyName const&) override;
     virtual MarkedValueList internal_own_property_keys() const override;
 

Userland/Libraries/LibJS/Runtime/Object.cpp

@@ -137,7 +137,7 @@ bool Object::create_data_property(PropertyName const& property_name, Value value
     };
 
     // 4. Return ? O.[[DefineOwnProperty]](P, newDesc).
-    return internal_define_own_property(property_name, new_descriptor);
+    return TRY_OR_DISCARD(internal_define_own_property(property_name, new_descriptor));
 }
 
 // 7.3.6 CreateMethodProperty ( O, P, V ), https://tc39.es/ecma262/#sec-createmethodproperty
@@ -159,7 +159,7 @@ bool Object::create_method_property(PropertyName const& property_name, Value val
     };
 
     // 4. Return ? O.[[DefineOwnProperty]](P, newDesc).
-    return internal_define_own_property(property_name, new_descriptor);
+    return TRY_OR_DISCARD(internal_define_own_property(property_name, new_descriptor));
 }
 
 // 7.3.7 CreateDataPropertyOrThrow ( O, P, V ), https://tc39.es/ecma262/#sec-createdatapropertyorthrow
@@ -213,9 +213,7 @@ bool Object::define_property_or_throw(PropertyName const& property_name, Propert
     VERIFY(property_name.is_valid());
 
     // 3. Let success be ? O.[[DefineOwnProperty]](P, desc).
-    auto success = internal_define_own_property(property_name, property_descriptor);
+    auto success = TRY_OR_DISCARD(internal_define_own_property(property_name, property_descriptor));
-    if (vm.exception())
-        return {};
 
     // 4. If success is false, throw a TypeError exception.
     if (!success) {
@@ -600,18 +598,18 @@ ThrowCompletionOr<Optional<PropertyDescriptor>> Object::internal_get_own_propert
 }
 
 // 10.1.6 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots-defineownproperty-p-desc
-bool Object::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
+ThrowCompletionOr<bool> Object::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
 {
     VERIFY(property_name.is_valid());
     auto& vm = this->vm();
 
     // 1. Let current be ? O.[[GetOwnProperty]](P).
-    auto current = TRY_OR_DISCARD(internal_get_own_property(property_name));
+    auto current = TRY(internal_get_own_property(property_name));
 
     // 2. Let extensible be ? IsExtensible(O).
     auto extensible = is_extensible();
-    if (vm.exception())
+    if (auto* exception = vm.exception())
-        return {};
+        return throw_completion(exception->value());
 
     // 3. Return ValidateAndApplyPropertyDescriptor(O, P, extensible, Desc, current).
     return validate_and_apply_property_descriptor(this, property_name, extensible, property_descriptor, current);
@@ -759,7 +757,7 @@ bool Object::ordinary_set_with_own_descriptor(PropertyName const& property_name,
             auto value_descriptor = PropertyDescriptor { .value = value };
 
             // iv. Return ? Receiver.[[DefineOwnProperty]](P, valueDesc).
-            return receiver.as_object().internal_define_own_property(property_name, value_descriptor);
+            return TRY_OR_DISCARD(receiver.as_object().internal_define_own_property(property_name, value_descriptor));
         }
         // e. Else,
         else {
@@ -783,6 +781,8 @@ bool Object::ordinary_set_with_own_descriptor(PropertyName const& property_name,
 
     // 7. Perform ? Call(setter, Receiver, « V »).
     (void)vm.call(*setter, receiver, value);
+    if (vm.exception())
+        return {};
 
     // 8. Return true.
     return true;

Userland/Libraries/LibJS/Runtime/Object.h

@@ -96,7 +96,7 @@ public:
     virtual ThrowCompletionOr<bool> internal_is_extensible() const;
     virtual ThrowCompletionOr<bool> internal_prevent_extensions();
     virtual ThrowCompletionOr<Optional<PropertyDescriptor>> internal_get_own_property(PropertyName const&) const;
-    virtual bool internal_define_own_property(PropertyName const&, PropertyDescriptor const&);
+    virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&);
     virtual bool internal_has_property(PropertyName const&) const;
     virtual Value internal_get(PropertyName const&, Value receiver) const;
     virtual bool internal_set(PropertyName const&, Value value, Value receiver);

Userland/Libraries/LibJS/Runtime/ProxyObject.cpp

@@ -330,7 +330,7 @@ ThrowCompletionOr<Optional<PropertyDescriptor>> ProxyObject::internal_get_own_pr
 }
 
 // 10.5.6 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc
-bool ProxyObject::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
+ThrowCompletionOr<bool> ProxyObject::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
 {
     auto& vm = this->vm();
     auto& global_object = this->global_object();
@@ -341,16 +341,14 @@ bool ProxyObject::internal_define_own_property(PropertyName const& property_name
     // 2. Let handler be O.[[ProxyHandler]].
 
     // 3. If handler is null, throw a TypeError exception.
-    if (m_is_revoked) {
+    if (m_is_revoked)
-        vm.throw_exception<TypeError>(global_object, ErrorType::ProxyRevoked);
+        return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyRevoked);
-        return {};
-    }
 
     // 4. Assert: Type(handler) is Object.
     // 5. Let target be O.[[ProxyTarget]].
 
     // 6. Let trap be ? GetMethod(handler, "defineProperty").
-    auto trap = TRY_OR_DISCARD(Value(&m_handler).get_method(global_object, vm.names.defineProperty));
+    auto trap = TRY(Value(&m_handler).get_method(global_object, vm.names.defineProperty));
 
     // 7. If trap is undefined, then
     if (!trap) {
@@ -362,19 +360,19 @@ bool ProxyObject::internal_define_own_property(PropertyName const& property_name
     auto descriptor_object = from_property_descriptor(global_object, property_descriptor);
 
     // 9. Let booleanTrapResult be ! ToBoolean(? Call(trap, handler, « target, P, descObj »)).
-    auto trap_result = TRY_OR_DISCARD(vm.call(*trap, &m_handler, &m_target, property_name_to_value(vm, property_name), descriptor_object)).to_boolean();
+    auto trap_result = TRY(vm.call(*trap, &m_handler, &m_target, property_name_to_value(vm, property_name), descriptor_object)).to_boolean();
 
     // 10. If booleanTrapResult is false, return false.
     if (!trap_result)
         return false;
 
     // 11. Let targetDesc be ? target.[[GetOwnProperty]](P).
-    auto target_descriptor = TRY_OR_DISCARD(m_target.internal_get_own_property(property_name));
+    auto target_descriptor = TRY(m_target.internal_get_own_property(property_name));
 
     // 12. Let extensibleTarget be ? IsExtensible(target).
     auto extensible_target = m_target.is_extensible();
-    if (vm.exception())
+    if (auto* exception = vm.exception())
-        return {};
+        return throw_completion(exception->value());
 
     // 14. Else, let settingConfigFalse be false.
     bool setting_config_false = false;
@@ -388,35 +386,28 @@ bool ProxyObject::internal_define_own_property(PropertyName const& property_name
     // 15. If targetDesc is undefined, then
     if (!target_descriptor.has_value()) {
         // a. If extensibleTarget is false, throw a TypeError exception.
-        if (!extensible_target) {
+        if (!extensible_target)
-            vm.throw_exception<TypeError>(global_object, ErrorType::ProxyDefinePropNonExtensible);
+            return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyDefinePropNonExtensible);
-            return {};
+
-        }
         // b. If settingConfigFalse is true, throw a TypeError exception.
-        if (setting_config_false) {
+        if (setting_config_false)
-            vm.throw_exception<TypeError>(global_object, ErrorType::ProxyDefinePropNonConfigurableNonExisting);
+            return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyDefinePropNonConfigurableNonExisting);
-            return {};
-        }
     }
     // 16. Else,
     else {
         // a. If IsCompatiblePropertyDescriptor(extensibleTarget, Desc, targetDesc) is false, throw a TypeError exception.
-        if (!is_compatible_property_descriptor(extensible_target, property_descriptor, target_descriptor)) {
+        if (!is_compatible_property_descriptor(extensible_target, property_descriptor, target_descriptor))
-            vm.throw_exception<TypeError>(global_object, ErrorType::ProxyDefinePropIncompatibleDescriptor);
+            return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyDefinePropIncompatibleDescriptor);
-            return {};
+
-        }
         // b. If settingConfigFalse is true and targetDesc.[[Configurable]] is true, throw a TypeError exception.
-        if (setting_config_false && *target_descriptor->configurable) {
+        if (setting_config_false && *target_descriptor->configurable)
-            vm.throw_exception<TypeError>(global_object, ErrorType::ProxyDefinePropExistingConfigurable);
+            return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyDefinePropExistingConfigurable);
-            return {};
+
-        }
         // c. If IsDataDescriptor(targetDesc) is true, targetDesc.[[Configurable]] is false, and targetDesc.[[Writable]] is true, then
         if (target_descriptor->is_data_descriptor() && !*target_descriptor->configurable && *target_descriptor->writable) {
             // i. If Desc has a [[Writable]] field and Desc.[[Writable]] is false, throw a TypeError exception.
-            if (property_descriptor.writable.has_value() && !*property_descriptor.writable) {
+            if (property_descriptor.writable.has_value() && !*property_descriptor.writable)
-                vm.throw_exception<TypeError>(global_object, ErrorType::ProxyDefinePropNonWritable);
+                return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyDefinePropNonWritable);
-                return {};
-            }
         }
     }
 

Userland/Libraries/LibJS/Runtime/ProxyObject.h

@@ -40,7 +40,7 @@ public:
     virtual ThrowCompletionOr<bool> internal_is_extensible() const override;
     virtual ThrowCompletionOr<bool> internal_prevent_extensions() override;
     virtual ThrowCompletionOr<Optional<PropertyDescriptor>> internal_get_own_property(PropertyName const&) const override;
-    virtual bool internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
+    virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
     virtual bool internal_has_property(PropertyName const&) const override;
     virtual Value internal_get(PropertyName const&, Value receiver) const override;
     virtual bool internal_set(PropertyName const&, Value value, Value receiver) override;

Userland/Libraries/LibJS/Runtime/ReflectObject.cpp

@@ -122,7 +122,7 @@ JS_DEFINE_NATIVE_FUNCTION(ReflectObject::define_property)
         return {};
 
     // 4. Return ? target.[[DefineOwnProperty]](key, desc).
-    return Value(target.as_object().internal_define_own_property(key, descriptor));
+    return Value(TRY_OR_DISCARD(target.as_object().internal_define_own_property(key, descriptor)));
 }
 
 // 28.1.4 Reflect.deleteProperty ( target, propertyKey ), https://tc39.es/ecma262/#sec-reflect.deleteproperty

Userland/Libraries/LibJS/Runtime/StringObject.cpp

@@ -108,7 +108,7 @@ ThrowCompletionOr<Optional<PropertyDescriptor>> StringObject::internal_get_own_p
 }
 
 // 10.4.3.2 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-string-exotic-objects-defineownproperty-p-desc
-bool StringObject::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
+ThrowCompletionOr<bool> StringObject::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
 {
     // 1. Assert: IsPropertyKey(P) is true.
     VERIFY(property_name.is_valid());

Userland/Libraries/LibJS/Runtime/StringObject.h

@@ -28,7 +28,7 @@ public:
 
 private:
     virtual ThrowCompletionOr<Optional<PropertyDescriptor>> internal_get_own_property(PropertyName const&) const override;
-    virtual bool internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
+    virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
     virtual MarkedValueList internal_own_property_keys() const override;
 
     virtual bool is_string_object() const final { return true; }

Userland/Libraries/LibJS/Runtime/TypedArray.h

@@ -254,7 +254,7 @@ public:
     }
 
     // 10.4.5.3 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-integer-indexed-exotic-objects-defineownproperty-p-desc
-    virtual bool internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor) override
+    virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor) override
     {
         // 1. Assert: IsPropertyKey(P) is true.
         VERIFY(property_name.is_valid());
@@ -295,8 +295,8 @@ public:
                 // vi. If Desc has a [[Value]] field, perform ? IntegerIndexedElementSet(O, numericIndex, Desc.[[Value]]).
                 if (property_descriptor.value.has_value()) {
                     integer_indexed_element_set<T>(*this, numeric_index, *property_descriptor.value);
-                    if (vm().exception())
+                    if (auto* exception = vm().exception())
-                        return {};
+                        return throw_completion(exception->value());
                 }
 
                 // vii. Return true.

Userland/Libraries/LibWeb/Bindings/Replaceable.h

@@ -6,11 +6,12 @@
 
 #pragma once
 
-#define REPLACEABLE_PROPERTY_SETTER(ObjectType, property)                                                                                 \
+#define REPLACEABLE_PROPERTY_SETTER(ObjectType, property)                                                \
-    auto this_value = vm.this_value(global_object);                                                                                       \
+    auto this_value = vm.this_value(global_object);                                                      \
-    if (!this_value.is_object() || !is<ObjectType>(this_value.as_object())) {                                                             \
+    if (!this_value.is_object() || !is<ObjectType>(this_value.as_object())) {                            \
-        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, #ObjectType);                                  \
+        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, #ObjectType); \
-        return {};                                                                                                                        \
+        return {};                                                                                       \
-    }                                                                                                                                     \
+    }                                                                                                    \
-    this_value.as_object().internal_define_own_property(#property, JS::PropertyDescriptor { .value = vm.argument(0), .writable = true }); \
+    TRY_OR_DISCARD(this_value.as_object().internal_define_own_property(                                  \
+        #property, JS::PropertyDescriptor { .value = vm.argument(0), .writable = true }));               \
     return JS::js_undefined();

Userland/Services/WebContent/ConsoleGlobalObject.cpp

@@ -65,7 +65,7 @@ JS::ThrowCompletionOr<Optional<JS::PropertyDescriptor>> ConsoleGlobalObject::int
     return Base::internal_get_own_property(property_name);
 }
 
-bool ConsoleGlobalObject::internal_define_own_property(JS::PropertyName const& property_name, JS::PropertyDescriptor const& descriptor)
+JS::ThrowCompletionOr<bool> ConsoleGlobalObject::internal_define_own_property(JS::PropertyName const& property_name, JS::PropertyDescriptor const& descriptor)
 {
     return m_window_object->internal_define_own_property(property_name, descriptor);
 }

Userland/Services/WebContent/ConsoleGlobalObject.h

@@ -28,7 +28,7 @@ public:
     virtual JS::ThrowCompletionOr<bool> internal_is_extensible() const override;
     virtual JS::ThrowCompletionOr<bool> internal_prevent_extensions() override;
     virtual JS::ThrowCompletionOr<Optional<JS::PropertyDescriptor>> internal_get_own_property(JS::PropertyName const& name) const override;
-    virtual bool internal_define_own_property(JS::PropertyName const& name, JS::PropertyDescriptor const& descriptor) override;
+    virtual JS::ThrowCompletionOr<bool> internal_define_own_property(JS::PropertyName const& name, JS::PropertyDescriptor const& descriptor) override;
     virtual bool internal_has_property(JS::PropertyName const& name) const override;
     virtual JS::Value internal_get(JS::PropertyName const&, JS::Value) const override;
     virtual bool internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;