LibJS: Convert internal_set() to ThrowCompletionOr

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

@@ -1397,7 +1397,7 @@ public:
     }
     if (interface.extended_attributes.contains("CustomSet")) {
         generator.append(R"~~~(
-    virtual bool internal_set(JS::PropertyName const&, JS::Value, JS::Value receiver) override;
+    virtual JS::ThrowCompletionOr<bool> internal_set(JS::PropertyName const&, JS::Value, JS::Value receiver) override;
 )~~~");
     }
 
@@ -1416,7 +1416,7 @@ public:
     if (interface.is_legacy_platform_object()) {
         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 JS::ThrowCompletionOr<bool> internal_set(JS::PropertyName const&, JS::Value, JS::Value) 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;
@@ -1986,7 +1986,7 @@ JS::ThrowCompletionOr<Optional<JS::PropertyDescriptor>> @class_name@::internal_g
 
         // 3.9.2. [[Set]], https://heycam.github.io/webidl/#legacy-platform-object-set
         scoped_generator.append(R"~~~(
-bool @class_name@::internal_set(JS::PropertyName const& property_name, JS::Value value, JS::Value receiver)
+JS::ThrowCompletionOr<bool> @class_name@::internal_set(JS::PropertyName const& property_name, JS::Value value, JS::Value receiver)
 {
     auto& vm = this->vm();
     [[maybe_unused]] auto& global_object = this->global_object();
@@ -2006,8 +2006,8 @@ bool @class_name@::internal_set(JS::PropertyName const& property_name, JS::Value
         if (IDL::is_an_array_index(global_object, property_name)) {
             // 1. Invoke the indexed property setter on O with P and V.
             invoke_indexed_property_setter(global_object, impl(), property_name, value);
-            if (vm.exception())
-                return {};
+            if (auto* exception = vm.exception())
+                return JS::throw_completion(exception->value());
 
             // 2. Return true.
             return true;
@@ -2022,8 +2022,8 @@ bool @class_name@::internal_set(JS::PropertyName const& property_name, JS::Value
         if (property_name.is_string()) {
             // 1. Invoke the named property setter on O with P and V.
             invoke_named_property_setter(global_object, impl(), property_name.as_string(), value);
-            if (vm.exception())
-                return {};
+            if (auto* exception = vm.exception())
+                return JS::throw_completion(exception->value());
 
             // 2. Return true.
             return true;
@@ -2039,13 +2039,16 @@ bool @class_name@::internal_set(JS::PropertyName const& property_name, JS::Value
         scoped_generator.append(R"~~~(
     // 2. Let ownDesc be LegacyPlatformObjectGetOwnProperty(O, P, true).
     auto own_descriptor = legacy_platform_object_get_own_property_for_set_slot(property_name);
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return JS::throw_completion(exception->value());
 
     // 3. Perform ? OrdinarySetWithOwnDescriptor(O, P, V, Receiver, ownDesc).
     // NOTE: The spec says "perform" instead of "return", meaning nothing will be returned on this path according to the spec, which isn't possible to do.
     //       Let's treat it as though it says "return" instead of "perform".
-    return ordinary_set_with_own_descriptor(property_name, value, receiver, own_descriptor);
+    auto result = ordinary_set_with_own_descriptor(property_name, value, receiver, own_descriptor);
+    if (auto* exception = vm.exception())
+        return JS::throw_completion(exception->value());
+    return result;
 }
 )~~~");
 

Userland/Applications/Spreadsheet/JSIntegration.cpp

@@ -121,7 +121,7 @@ JS::ThrowCompletionOr<JS::Value> SheetGlobalObject::internal_get(const JS::Prope
     return Base::internal_get(property_name, receiver);
 }
 
-bool SheetGlobalObject::internal_set(const JS::PropertyName& property_name, JS::Value value, JS::Value receiver)
+JS::ThrowCompletionOr<bool> SheetGlobalObject::internal_set(const JS::PropertyName& property_name, JS::Value value, JS::Value receiver)
 {
     if (property_name.is_string()) {
         if (auto pos = m_sheet.parse_cell_name(property_name.as_string()); pos.has_value()) {

Userland/Applications/Spreadsheet/JSIntegration.h

@@ -28,7 +28,7 @@ public:
     virtual ~SheetGlobalObject() override;
 
     virtual JS::ThrowCompletionOr<JS::Value> internal_get(JS::PropertyName const&, JS::Value receiver) const override;
-    virtual bool internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;
+    virtual JS::ThrowCompletionOr<bool> internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;
     virtual void initialize_global_object() override;
 
     JS_DECLARE_NATIVE_FUNCTION(get_real_cell_contents);

Userland/DevTools/HackStudio/Debugger/DebuggerGlobalJSObject.cpp

@@ -40,7 +40,7 @@ JS::ThrowCompletionOr<JS::Value> DebuggerGlobalJSObject::internal_get(JS::Proper
     return vm().throw_completion<JS::TypeError>(const_cast<DebuggerGlobalJSObject&>(*this), move(error_string));
 }
 
-bool DebuggerGlobalJSObject::internal_set(JS::PropertyName const& property_name, JS::Value value, JS::Value receiver)
+JS::ThrowCompletionOr<bool> DebuggerGlobalJSObject::internal_set(JS::PropertyName const& property_name, JS::Value value, JS::Value receiver)
 {
     if (m_variables.is_empty() || !property_name.is_string())
         return Base::internal_set(property_name, value, receiver);
@@ -55,8 +55,7 @@ bool DebuggerGlobalJSObject::internal_set(JS::PropertyName const& property_name,
     if (debugger_value.has_value())
         return Debugger::the().session()->poke((u32*)target_variable.location_data.address, debugger_value.value());
     auto error_string = String::formatted("Cannot convert JS value {} to variable {} of type {}", value.to_string_without_side_effects(), property_name.as_string(), target_variable.type_name);
-    vm().throw_exception<JS::TypeError>(const_cast<DebuggerGlobalJSObject&>(*this), error_string);
-    return {};
+    return vm().throw_completion<JS::TypeError>(const_cast<DebuggerGlobalJSObject&>(*this), move(error_string));
 }
 
 Optional<JS::Value> DebuggerGlobalJSObject::debugger_to_js(const Debug::DebugInfo::VariableInfo& variable) const

Userland/DevTools/HackStudio/Debugger/DebuggerGlobalJSObject.h

@@ -22,7 +22,7 @@ public:
     DebuggerGlobalJSObject();
 
     virtual JS::ThrowCompletionOr<JS::Value> internal_get(JS::PropertyName const&, JS::Value receiver) const override;
-    virtual bool internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;
+    virtual JS::ThrowCompletionOr<bool> internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;
 
     Optional<JS::Value> debugger_to_js(const Debug::DebugInfo::VariableInfo&) const;
     Optional<u32> js_to_debugger(JS::Value value, const Debug::DebugInfo::VariableInfo&) const;

Userland/DevTools/HackStudio/Debugger/DebuggerVariableJSObject.cpp

@@ -7,6 +7,7 @@
 
 #include "DebuggerVariableJSObject.h"
 #include "Debugger.h"
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/Error.h>
 #include <LibJS/Runtime/PrimitiveString.h>
 #include <LibJS/Runtime/PropertyName.h>
@@ -28,30 +29,26 @@ DebuggerVariableJSObject::~DebuggerVariableJSObject()
 {
 }
 
-bool DebuggerVariableJSObject::internal_set(const JS::PropertyName& property_name, JS::Value value, JS::Value)
+JS::ThrowCompletionOr<bool> DebuggerVariableJSObject::internal_set(const JS::PropertyName& property_name, JS::Value value, JS::Value)
 {
-    if (!property_name.is_string()) {
-        vm().throw_exception<JS::TypeError>(global_object(), String::formatted("Invalid variable name {}", property_name.to_string()));
-        return false;
-    }
+    auto& vm = this->vm();
+
+    if (!property_name.is_string())
+        return vm.throw_completion<JS::TypeError>(global_object(), String::formatted("Invalid variable name {}", property_name.to_string()));
 
     auto name = property_name.as_string();
     auto it = m_variable_info.members.find_if([&](auto& variable) {
         return variable->name == name;
     });
 
-    if (it.is_end()) {
-        vm().throw_exception<JS::TypeError>(global_object(), String::formatted("Variable of type {} has no property {}", m_variable_info.type_name, property_name));
-        return false;
-    }
+    if (it.is_end())
+        return vm.throw_completion<JS::TypeError>(global_object(), String::formatted("Variable of type {} has no property {}", m_variable_info.type_name, property_name));
 
     auto& member = **it;
     auto new_value = debugger_object().js_to_debugger(value, member);
-    if (!new_value.has_value()) {
-        auto string_error = String::formatted("Cannot convert JS value {} to variable {} of type {}", value.to_string_without_side_effects(), name, member.type_name);
-        vm().throw_exception<JS::TypeError>(global_object(), string_error);
-        return false;
-    }
+    if (!new_value.has_value())
+        return vm.throw_completion<JS::TypeError>(global_object(), String::formatted("Cannot convert JS value {} to variable {} of type {}", value.to_string_without_side_effects(), name, member.type_name));
+
     Debugger::the().session()->poke((u32*)member.location_data.address, new_value.value());
     return true;
 }

Userland/DevTools/HackStudio/Debugger/DebuggerVariableJSObject.h

@@ -9,6 +9,7 @@
 
 #include "DebuggerGlobalJSObject.h"
 #include <LibDebug/DebugInfo.h>
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/Object.h>
 
 namespace HackStudio {
@@ -24,7 +25,7 @@ public:
 
     virtual const char* class_name() const override { return m_variable_info.type_name.characters(); }
 
-    bool internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;
+    JS::ThrowCompletionOr<bool> internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;
 
 private:
     DebuggerGlobalJSObject& debugger_object() const;

Userland/Libraries/LibJS/Runtime/ArgumentsObject.cpp

@@ -54,7 +54,7 @@ ThrowCompletionOr<Value> ArgumentsObject::internal_get(PropertyName const& prope
 }
 
 // 10.4.4.4 [[Set]] ( P, V, Receiver ), https://tc39.es/ecma262/#sec-arguments-exotic-objects-set-p-v-receiver
-bool ArgumentsObject::internal_set(PropertyName const& property_name, Value value, Value receiver)
+ThrowCompletionOr<bool> ArgumentsObject::internal_set(PropertyName const& property_name, Value value, Value receiver)
 {
     bool is_mapped = false;
 

Userland/Libraries/LibJS/Runtime/ArgumentsObject.h

@@ -26,7 +26,7 @@ public:
     virtual ThrowCompletionOr<Optional<PropertyDescriptor>> internal_get_own_property(PropertyName const&) const override;
     virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
     virtual ThrowCompletionOr<Value> internal_get(PropertyName const&, Value receiver) const override;
-    virtual bool internal_set(PropertyName const&, Value value, Value receiver) override;
+    virtual ThrowCompletionOr<bool> internal_set(PropertyName const&, Value value, Value receiver) override;
     virtual bool internal_delete(PropertyName const&) override;
 
     // [[ParameterMap]]

Userland/Libraries/LibJS/Runtime/Object.cpp

@@ -105,9 +105,7 @@ bool Object::set(PropertyName const& property_name, Value value, ShouldThrowExce
     // 3. Assert: Type(Throw) is Boolean.
 
     // 4. Let success be ? O.[[Set]](P, V, O).
-    auto success = internal_set(property_name, value, this);
-    if (vm.exception())
-        return {};
+    auto success = TRY_OR_DISCARD(internal_set(property_name, value, this));
 
     // 5. If success is false and Throw is true, throw a TypeError exception.
     if (!success && throw_exceptions == ShouldThrowExceptions::Yes) {
@@ -690,19 +688,23 @@ ThrowCompletionOr<Value> Object::internal_get(PropertyName const& property_name,
 }
 
 // 10.1.9 [[Set]] ( P, V, Receiver ), https://tc39.es/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots-set-p-v-receiver
-bool Object::internal_set(PropertyName const& property_name, Value value, Value receiver)
+ThrowCompletionOr<bool> Object::internal_set(PropertyName const& property_name, Value value, Value receiver)
 {
     VERIFY(!value.is_empty());
     VERIFY(!receiver.is_empty());
+    auto& vm = this->vm();
 
     // 1. Assert: IsPropertyKey(P) is true.
     VERIFY(property_name.is_valid());
 
     // 2. Let ownDesc be ? O.[[GetOwnProperty]](P).
-    auto own_descriptor = TRY_OR_DISCARD(internal_get_own_property(property_name));
+    auto own_descriptor = TRY(internal_get_own_property(property_name));
 
     // 3. Return OrdinarySetWithOwnDescriptor(O, P, V, Receiver, ownDesc).
-    return ordinary_set_with_own_descriptor(property_name, value, receiver, own_descriptor);
+    auto success = ordinary_set_with_own_descriptor(property_name, value, receiver, own_descriptor);
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
+    return success;
 }
 
 // 10.1.9.2 OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc ), https://tc39.es/ecma262/#sec-ordinarysetwithowndescriptor
@@ -721,7 +723,7 @@ bool Object::ordinary_set_with_own_descriptor(PropertyName const& property_name,
         // b. If parent is not null, then
         if (parent) {
             // i. Return ? parent.[[Set]](P, V, Receiver).
-            return parent->internal_set(property_name, value, receiver);
+            return TRY_OR_DISCARD(parent->internal_set(property_name, value, receiver));
         }
         // c. Else,
         else {

Userland/Libraries/LibJS/Runtime/Object.h

@@ -99,7 +99,7 @@ public:
     virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&);
     virtual ThrowCompletionOr<bool> internal_has_property(PropertyName const&) const;
     virtual ThrowCompletionOr<Value> internal_get(PropertyName const&, Value receiver) const;
-    virtual bool internal_set(PropertyName const&, Value value, Value receiver);
+    virtual ThrowCompletionOr<bool> internal_set(PropertyName const&, Value value, Value receiver);
     virtual bool internal_delete(PropertyName const&);
     virtual MarkedValueList internal_own_property_keys() const;
 

Userland/Libraries/LibJS/Runtime/ProxyObject.cpp

@@ -543,7 +543,7 @@ ThrowCompletionOr<Value> ProxyObject::internal_get(PropertyName const& property_
 }
 
 // 10.5.9 [[Set]] ( P, V, Receiver ), https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-set-p-v-receiver
-bool ProxyObject::internal_set(PropertyName const& property_name, Value value, Value receiver)
+ThrowCompletionOr<bool> ProxyObject::internal_set(PropertyName const& property_name, Value value, Value receiver)
 {
     VERIFY(!value.is_empty());
     VERIFY(!receiver.is_empty());
@@ -557,16 +557,14 @@ bool ProxyObject::internal_set(PropertyName const& property_name, Value value, V
     // 2. Let handler be O.[[ProxyHandler]].
 
     // 3. If handler is null, throw a TypeError exception.
-    if (m_is_revoked) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::ProxyRevoked);
-        return {};
-    }
+    if (m_is_revoked)
+        return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyRevoked);
 
     // 4. Assert: Type(handler) is Object.
     // 5. Let target be O.[[ProxyTarget]].
 
     // 6. Let trap be ? GetMethod(handler, "set").
-    auto trap = TRY_OR_DISCARD(Value(&m_handler).get_method(global_object, vm.names.set));
+    auto trap = TRY(Value(&m_handler).get_method(global_object, vm.names.set));
 
     // 7. If trap is undefined, then
     if (!trap) {
@@ -575,32 +573,28 @@ bool ProxyObject::internal_set(PropertyName const& property_name, Value value, V
     }
 
     // 8. Let booleanTrapResult be ! ToBoolean(? Call(trap, handler, « target, P, V, Receiver »)).
-    auto trap_result = TRY_OR_DISCARD(vm.call(*trap, &m_handler, &m_target, property_name_to_value(vm, property_name), value, receiver)).to_boolean();
+    auto trap_result = TRY(vm.call(*trap, &m_handler, &m_target, property_name_to_value(vm, property_name), value, receiver)).to_boolean();
 
     // 9. If booleanTrapResult is false, return false.
     if (!trap_result)
         return false;
 
     // 10. 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));
 
     // 11. If targetDesc is not undefined and targetDesc.[[Configurable]] is false, then
     if (target_descriptor.has_value() && !*target_descriptor->configurable) {
         // a. If IsDataDescriptor(targetDesc) is true and targetDesc.[[Writable]] is false, then
         if (target_descriptor->is_data_descriptor() && !*target_descriptor->writable) {
             // i. If SameValue(V, targetDesc.[[Value]]) is false, throw a TypeError exception.
-            if (!same_value(value, *target_descriptor->value)) {
-                vm.throw_exception<TypeError>(global_object, ErrorType::ProxySetImmutableDataProperty);
-                return {};
-            }
+            if (!same_value(value, *target_descriptor->value))
+                return vm.throw_completion<TypeError>(global_object, ErrorType::ProxySetImmutableDataProperty);
         }
         // b. If IsAccessorDescriptor(targetDesc) is true, then
         if (target_descriptor->is_accessor_descriptor()) {
             // i. If targetDesc.[[Set]] is undefined, throw a TypeError exception.
-            if (!*target_descriptor->set) {
-                vm.throw_exception<TypeError>(global_object, ErrorType::ProxySetNonConfigurableAccessor);
-                return {};
-            }
+            if (!*target_descriptor->set)
+                return vm.throw_completion<TypeError>(global_object, ErrorType::ProxySetNonConfigurableAccessor);
         }
     }
 

Userland/Libraries/LibJS/Runtime/ProxyObject.h

@@ -43,7 +43,7 @@ public:
     virtual ThrowCompletionOr<bool> internal_define_own_property(PropertyName const&, PropertyDescriptor const&) override;
     virtual ThrowCompletionOr<bool> internal_has_property(PropertyName const&) const override;
     virtual ThrowCompletionOr<Value> internal_get(PropertyName const&, Value receiver) const override;
-    virtual bool internal_set(PropertyName const&, Value value, Value receiver) override;
+    virtual ThrowCompletionOr<bool> internal_set(PropertyName const&, Value value, Value receiver) override;
     virtual bool internal_delete(PropertyName const&) override;
     virtual MarkedValueList internal_own_property_keys() const override;
 

Userland/Libraries/LibJS/Runtime/Reference.cpp

@@ -39,9 +39,10 @@ void Reference::put_value(GlobalObject& global_object, Value value)
         if (!base_obj)
             return;
 
-        bool succeeded = base_obj->internal_set(m_name, value, get_this_value());
-        if (vm.exception())
+        auto succeeded_or_error = base_obj->internal_set(m_name, value, get_this_value());
+        if (succeeded_or_error.is_error())
             return;
+        auto succeeded = succeeded_or_error.release_value();
         if (!succeeded && m_strict) {
             vm.throw_exception<TypeError>(global_object, ErrorType::ReferenceNullishSetProperty, m_name, m_base_value.to_string_without_side_effects());
             return;

Userland/Libraries/LibJS/Runtime/ReflectObject.cpp

@@ -310,7 +310,7 @@ JS_DEFINE_NATIVE_FUNCTION(ReflectObject::set)
     }
 
     // 4. Return ? target.[[Set]](key, V, receiver).
-    return Value(target.as_object().internal_set(key, value, receiver));
+    return Value(TRY_OR_DISCARD(target.as_object().internal_set(key, value, receiver)));
 }
 
 // 28.1.13 Reflect.setPrototypeOf ( target, proto ), https://tc39.es/ecma262/#sec-reflect.setprototypeof

Userland/Libraries/LibJS/Runtime/TypedArray.h

@@ -336,7 +336,7 @@ public:
     }
 
     // 10.4.5.5 [[Set]] ( P, V, Receiver ), https://tc39.es/ecma262/#sec-integer-indexed-exotic-objects-set-p-v-receiver
-    virtual bool internal_set(PropertyName const& property_name, Value value, Value receiver) override
+    virtual ThrowCompletionOr<bool> internal_set(PropertyName const& property_name, Value value, Value receiver) override
     {
         VERIFY(!value.is_empty());
         VERIFY(!receiver.is_empty());
@@ -356,8 +356,8 @@ public:
             if (!numeric_index.is_undefined()) {
                 // i. Perform ? IntegerIndexedElementSet(O, numericIndex, V).
                 integer_indexed_element_set<T>(*this, numeric_index, value);
-                if (vm().exception())
-                    return {};
+                if (auto* exception = vm().exception())
+                    return throw_completion(exception->value());
 
                 // ii. Return true.
                 return true;

Userland/Libraries/LibWeb/Bindings/CSSStyleDeclarationWrapperCustom.cpp

@@ -30,7 +30,7 @@ JS::ThrowCompletionOr<JS::Value> CSSStyleDeclarationWrapper::internal_get(JS::Pr
     return { js_string(vm(), String::empty()) };
 }
 
-bool CSSStyleDeclarationWrapper::internal_set(JS::PropertyName const& name, JS::Value value, JS::Value receiver)
+JS::ThrowCompletionOr<bool> CSSStyleDeclarationWrapper::internal_set(JS::PropertyName const& name, JS::Value value, JS::Value receiver)
 {
     if (!name.is_string())
         return Base::internal_set(name, value, receiver);
@@ -39,8 +39,8 @@ bool CSSStyleDeclarationWrapper::internal_set(JS::PropertyName const& name, JS::
         return Base::internal_set(name, value, receiver);
 
     auto css_text = value.to_string(global_object());
-    if (vm().exception())
-        return false;
+    if (auto* exception = vm().exception())
+        return JS::throw_completion(exception->value());
 
     impl().set_property(property_id, css_text);
     return true;

Userland/Services/WebContent/ConsoleGlobalObject.cpp

@@ -83,7 +83,7 @@ JS::ThrowCompletionOr<JS::Value> ConsoleGlobalObject::internal_get(JS::PropertyN
     return Base::internal_get(property_name, receiver);
 }
 
-bool ConsoleGlobalObject::internal_set(JS::PropertyName const& property_name, JS::Value value, JS::Value receiver)
+JS::ThrowCompletionOr<bool> ConsoleGlobalObject::internal_set(JS::PropertyName const& property_name, JS::Value value, JS::Value receiver)
 {
     return m_window_object->internal_set(property_name, value, (receiver == this) ? m_window_object : receiver);
 }

Userland/Services/WebContent/ConsoleGlobalObject.h

@@ -31,7 +31,7 @@ public:
     virtual JS::ThrowCompletionOr<bool> internal_define_own_property(JS::PropertyName const& name, JS::PropertyDescriptor const& descriptor) override;
     virtual JS::ThrowCompletionOr<bool> internal_has_property(JS::PropertyName const& name) const override;
     virtual JS::ThrowCompletionOr<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;
+    virtual JS::ThrowCompletionOr<bool> internal_set(JS::PropertyName const&, JS::Value value, JS::Value receiver) override;
     virtual bool internal_delete(JS::PropertyName const& name) override;
     virtual JS::MarkedValueList internal_own_property_keys() const override;