LibJS+Everywhere: Propagate Cell::initialize errors from Heap::allocate

Callers that are already in a fallible context will now TRY to allocate
cells. Callers in infallible contexts get a FIXME.

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

@@ -174,10 +174,10 @@ void Intrinsics::create_web_prototype_and_constructor<@prototype_class@>(JS::Rea
 {
     auto& vm = realm.vm();
 
-    auto prototype = heap().allocate<@prototype_class@>(realm, realm);
+    auto prototype = heap().allocate<@prototype_class@>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
     m_prototypes.set("@interface_name@"sv, prototype);
 
-    auto constructor = heap().allocate<@constructor_class@>(realm, realm);
+    auto constructor = heap().allocate<@constructor_class@>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
     m_constructors.set("@interface_name@"sv, constructor);
 
     prototype->define_direct_property(vm.names.constructor, constructor.ptr(), JS::Attribute::Writable | JS::Attribute::Configurable);
@@ -188,7 +188,7 @@ void Intrinsics::create_web_prototype_and_constructor<@prototype_class@>(JS::Rea
             gen.set("legacy_interface_name", legacy_constructor->name);
             gen.set("legacy_constructor_class", legacy_constructor->constructor_class);
             gen.append(R"~~~(
-    auto legacy_constructor = heap().allocate<@legacy_constructor_class@>(realm, realm);
+    auto legacy_constructor = heap().allocate<@legacy_constructor_class@>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
     m_constructors.set("@legacy_interface_name@"sv, legacy_constructor);
 
     legacy_constructor->define_direct_property(vm.names.name, JS::PrimitiveString::create(vm, "@legacy_interface_name@"sv), JS::Attribute::Configurable);)~~~");

Tests/LibWasm/test-wasm.cpp

@@ -51,7 +51,7 @@ public:
     static JS::ThrowCompletionOr<WebAssemblyModule*> create(JS::Realm& realm, Wasm::Module module, HashMap<Wasm::Linker::Name, Wasm::ExternValue> const& imports)
     {
         auto& vm = realm.vm();
-        auto instance = realm.heap().allocate<WebAssemblyModule>(realm, *realm.intrinsics().object_prototype());
+        auto instance = MUST_OR_THROW_OOM(realm.heap().allocate<WebAssemblyModule>(realm, *realm.intrinsics().object_prototype()));
         instance->m_module = move(module);
         Wasm::Linker linker(*instance->m_module);
         linker.link(imports);

Userland/Applications/Spreadsheet/Workbook.cpp

@@ -27,7 +27,7 @@ Workbook::Workbook(NonnullRefPtrVector<Sheet>&& sheets, GUI::Window& parent_wind
     , m_main_execution_context(m_vm->heap())
     , m_parent_window(parent_window)
 {
-    m_workbook_object = m_vm->heap().allocate<WorkbookObject>(m_interpreter->realm(), m_interpreter->realm(), *this);
+    m_workbook_object = m_vm->heap().allocate<WorkbookObject>(m_interpreter->realm(), m_interpreter->realm(), *this).release_allocated_value_but_fixme_should_propagate_errors();
     m_interpreter->realm().global_object().define_direct_property("workbook", workbook_object(), JS::default_attributes);
 
     m_main_execution_context.current_node = nullptr;

Userland/Libraries/LibJS/Contrib/Test262/$262Object.cpp

@@ -28,8 +28,8 @@ ThrowCompletionOr<void> $262Object::initialize(Realm& realm)
 {
     MUST_OR_THROW_OOM(Base::initialize(realm));
 
-    m_agent = vm().heap().allocate<AgentObject>(realm, realm);
-    m_is_htmldda = vm().heap().allocate<IsHTMLDDA>(realm, realm);
+    m_agent = MUST_OR_THROW_OOM(vm().heap().allocate<AgentObject>(realm, realm));
+    m_is_htmldda = MUST_OR_THROW_OOM(vm().heap().allocate<IsHTMLDDA>(realm, realm));
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, "clearKeptObjects", clear_kept_objects, 0, attr);

Userland/Libraries/LibJS/Contrib/Test262/GlobalObject.cpp

@@ -18,7 +18,7 @@ ThrowCompletionOr<void> GlobalObject::initialize(Realm& realm)
 {
     MUST_OR_THROW_OOM(Base::initialize(realm));
 
-    m_$262 = vm().heap().allocate<$262Object>(realm, realm);
+    m_$262 = MUST_OR_THROW_OOM(vm().heap().allocate<$262Object>(realm, realm));
 
     // https://github.com/tc39/test262/blob/master/INTERPRETING.md#host-defined-functions
     u8 attr = Attribute::Writable | Attribute::Configurable;

Userland/Libraries/LibJS/Heap/Heap.h

@@ -41,15 +41,12 @@ public:
     }
 
     template<typename T, typename... Args>
-    NonnullGCPtr<T> allocate(Realm& realm, Args&&... args)
+    ThrowCompletionOr<NonnullGCPtr<T>> allocate(Realm& realm, Args&&... args)
     {
         auto* memory = allocate_cell(sizeof(T));
         new (memory) T(forward<Args>(args)...);
         auto* cell = static_cast<T*>(memory);
-
-        // FIXME: Propagate this error.
-        (void)memory->initialize(realm);
-
+        MUST_OR_THROW_OOM(memory->initialize(realm));
         return *cell;
     }
 

Userland/Libraries/LibJS/Module.cpp

@@ -114,7 +114,7 @@ Object* Module::module_namespace_create(VM& vm, Vector<DeprecatedFlyString> unam
     // 6. Let sortedExports be a List whose elements are the elements of exports ordered as if an Array of the same values had been sorted using %Array.prototype.sort% using undefined as comparefn.
     // 7. Set M.[[Exports]] to sortedExports.
     // 8. Create own properties of M corresponding to the definitions in 28.3.
-    auto module_namespace = vm.heap().allocate<ModuleNamespaceObject>(realm, realm, this, move(unambiguous_names));
+    auto module_namespace = vm.heap().allocate<ModuleNamespaceObject>(realm, realm, this, move(unambiguous_names)).release_allocated_value_but_fixme_should_propagate_errors();
 
     // 9. Set module.[[Namespace]] to M.
     m_namespace = make_handle(module_namespace);

Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp

@@ -1104,7 +1104,7 @@ Object* create_mapped_arguments_object(VM& vm, FunctionObject& function, Vector<
     // 7. Set obj.[[Set]] as specified in 10.4.4.4.
     // 8. Set obj.[[Delete]] as specified in 10.4.4.5.
     // 9. Set obj.[[Prototype]] to %Object.prototype%.
-    auto object = vm.heap().allocate<ArgumentsObject>(realm, realm, environment);
+    auto object = vm.heap().allocate<ArgumentsObject>(realm, realm, environment).release_allocated_value_but_fixme_should_propagate_errors();
 
     // 14. Let index be 0.
     // 15. Repeat, while index < len,

Userland/Libraries/LibJS/Runtime/AbstractOperations.h

@@ -146,7 +146,7 @@ ThrowCompletionOr<NonnullGCPtr<T>> ordinary_create_from_constructor(VM& vm, Func
 {
     auto& realm = *vm.current_realm();
     auto* prototype = TRY(get_prototype_from_constructor(vm, constructor, intrinsic_default_prototype));
-    return realm.heap().allocate<T>(realm, forward<Args>(args)..., *prototype);
+    return MUST_OR_THROW_OOM(realm.heap().allocate<T>(realm, forward<Args>(args)..., *prototype));
 }
 
 // 14.1 MergeLists ( a, b ), https://tc39.es/proposal-temporal/#sec-temporal-mergelists

Userland/Libraries/LibJS/Runtime/AggregateError.cpp

@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<AggregateError> AggregateError::create(Realm& realm)
 {
-    return realm.heap().allocate<AggregateError>(realm, *realm.intrinsics().aggregate_error_prototype());
+    return realm.heap().allocate<AggregateError>(realm, *realm.intrinsics().aggregate_error_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 AggregateError::AggregateError(Object& prototype)

Userland/Libraries/LibJS/Runtime/Array.cpp

@@ -32,7 +32,7 @@ ThrowCompletionOr<NonnullGCPtr<Array>> Array::create(Realm& realm, u64 length, O
     // 3. Let A be MakeBasicObject(« [[Prototype]], [[Extensible]] »).
     // 4. Set A.[[Prototype]] to proto.
     // 5. Set A.[[DefineOwnProperty]] as specified in 10.4.2.1.
-    auto array = realm.heap().allocate<Array>(realm, *prototype);
+    auto array = MUST_OR_THROW_OOM(realm.heap().allocate<Array>(realm, *prototype));
 
     // 6. Perform ! OrdinaryDefineOwnProperty(A, "length", PropertyDescriptor { [[Value]]: 𝔽(length), [[Writable]]: true, [[Enumerable]]: false, [[Configurable]]: false }).
     MUST(array->internal_define_own_property(vm.names.length, { .value = Value(length), .writable = true, .enumerable = false, .configurable = false }));

Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp

@@ -17,17 +17,17 @@ ThrowCompletionOr<NonnullGCPtr<ArrayBuffer>> ArrayBuffer::create(Realm& realm, s
     if (buffer.is_error())
         return realm.vm().throw_completion<RangeError>(ErrorType::NotEnoughMemoryToAllocate, byte_length);
 
-    return realm.heap().allocate<ArrayBuffer>(realm, buffer.release_value(), *realm.intrinsics().array_buffer_prototype());
+    return MUST_OR_THROW_OOM(realm.heap().allocate<ArrayBuffer>(realm, buffer.release_value(), *realm.intrinsics().array_buffer_prototype()));
 }
 
 NonnullGCPtr<ArrayBuffer> ArrayBuffer::create(Realm& realm, ByteBuffer buffer)
 {
-    return realm.heap().allocate<ArrayBuffer>(realm, move(buffer), *realm.intrinsics().array_buffer_prototype());
+    return realm.heap().allocate<ArrayBuffer>(realm, move(buffer), *realm.intrinsics().array_buffer_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NonnullGCPtr<ArrayBuffer> ArrayBuffer::create(Realm& realm, ByteBuffer* buffer)
 {
-    return realm.heap().allocate<ArrayBuffer>(realm, buffer, *realm.intrinsics().array_buffer_prototype());
+    return realm.heap().allocate<ArrayBuffer>(realm, buffer, *realm.intrinsics().array_buffer_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 ArrayBuffer::ArrayBuffer(ByteBuffer buffer, Object& prototype)

Userland/Libraries/LibJS/Runtime/ArrayIterator.cpp

@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<ArrayIterator> ArrayIterator::create(Realm& realm, Value array, Object::PropertyKind iteration_kind)
 {
-    return realm.heap().allocate<ArrayIterator>(realm, array, iteration_kind, *realm.intrinsics().array_iterator_prototype());
+    return realm.heap().allocate<ArrayIterator>(realm, array, iteration_kind, *realm.intrinsics().array_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 ArrayIterator::ArrayIterator(Value array, Object::PropertyKind iteration_kind, Object& prototype)

Userland/Libraries/LibJS/Runtime/AsyncFromSyncIterator.cpp

@@ -13,7 +13,7 @@ namespace JS {
 
 NonnullGCPtr<AsyncFromSyncIterator> AsyncFromSyncIterator::create(Realm& realm, Iterator sync_iterator_record)
 {
-    return realm.heap().allocate<AsyncFromSyncIterator>(realm, realm, sync_iterator_record);
+    return realm.heap().allocate<AsyncFromSyncIterator>(realm, realm, sync_iterator_record).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 AsyncFromSyncIterator::AsyncFromSyncIterator(Realm& realm, Iterator sync_iterator_record)

Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.cpp

@@ -15,7 +15,7 @@ namespace JS {
 
 ThrowCompletionOr<Value> AsyncFunctionDriverWrapper::create(Realm& realm, GeneratorObject* generator_object)
 {
-    auto wrapper = realm.heap().allocate<AsyncFunctionDriverWrapper>(realm, realm, generator_object);
+    auto wrapper = MUST_OR_THROW_OOM(realm.heap().allocate<AsyncFunctionDriverWrapper>(realm, realm, generator_object));
     return wrapper->react_to_async_task_completion(realm.vm(), js_undefined(), true);
 }
 

Userland/Libraries/LibJS/Runtime/BigIntObject.cpp

@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<BigIntObject> BigIntObject::create(Realm& realm, BigInt& bigint)
 {
-    return realm.heap().allocate<BigIntObject>(realm, bigint, *realm.intrinsics().bigint_prototype());
+    return realm.heap().allocate<BigIntObject>(realm, bigint, *realm.intrinsics().bigint_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 BigIntObject::BigIntObject(BigInt& bigint, Object& prototype)

Userland/Libraries/LibJS/Runtime/BooleanObject.cpp

@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<BooleanObject> BooleanObject::create(Realm& realm, bool value)
 {
-    return realm.heap().allocate<BooleanObject>(realm, value, *realm.intrinsics().boolean_prototype());
+    return realm.heap().allocate<BooleanObject>(realm, value, *realm.intrinsics().boolean_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 BooleanObject::BooleanObject(bool value, Object& prototype)

Userland/Libraries/LibJS/Runtime/BoundFunction.cpp

@@ -26,7 +26,7 @@ ThrowCompletionOr<NonnullGCPtr<BoundFunction>> BoundFunction::create(Realm& real
     // 7. Set obj.[[BoundTargetFunction]] to targetFunction.
     // 8. Set obj.[[BoundThis]] to boundThis.
     // 9. Set obj.[[BoundArguments]] to boundArgs.
-    auto object = realm.heap().allocate<BoundFunction>(realm, realm, target_function, bound_this, move(bound_arguments), prototype);
+    auto object = MUST_OR_THROW_OOM(realm.heap().allocate<BoundFunction>(realm, realm, target_function, bound_this, move(bound_arguments), prototype));
 
     // 10. Return obj.
     return object;

Userland/Libraries/LibJS/Runtime/DataView.cpp

@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<DataView> DataView::create(Realm& realm, ArrayBuffer* viewed_buffer, size_t byte_length, size_t byte_offset)
 {
-    return realm.heap().allocate<DataView>(realm, viewed_buffer, byte_length, byte_offset, *realm.intrinsics().data_view_prototype());
+    return realm.heap().allocate<DataView>(realm, viewed_buffer, byte_length, byte_offset, *realm.intrinsics().data_view_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 DataView::DataView(ArrayBuffer* viewed_buffer, size_t byte_length, size_t byte_offset, Object& prototype)

Userland/Libraries/LibJS/Runtime/Date.cpp

@@ -25,7 +25,7 @@ Crypto::SignedBigInteger const ns_per_day_bigint { static_cast<i64>(ns_per_day)
 
 NonnullGCPtr<Date> Date::create(Realm& realm, double date_value)
 {
-    return realm.heap().allocate<Date>(realm, date_value, *realm.intrinsics().date_prototype());
+    return realm.heap().allocate<Date>(realm, date_value, *realm.intrinsics().date_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Date::Date(double date_value, Object& prototype)

Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp

@@ -45,12 +45,12 @@ NonnullGCPtr<ECMAScriptFunctionObject> ECMAScriptFunctionObject::create(Realm& r
         prototype = realm.intrinsics().async_generator_function_prototype();
         break;
     }
-    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, parent_environment, private_environment, *prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name));
+    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, parent_environment, private_environment, *prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NonnullGCPtr<ECMAScriptFunctionObject> ECMAScriptFunctionObject::create(Realm& realm, DeprecatedFlyString name, Object& prototype, DeprecatedString source_text, Statement const& ecmascript_code, Vector<FunctionParameter> parameters, i32 m_function_length, Environment* parent_environment, PrivateEnvironment* private_environment, FunctionKind kind, bool is_strict, bool might_need_arguments_object, bool contains_direct_call_to_eval, bool is_arrow_function, Variant<PropertyKey, PrivateName, Empty> class_field_initializer_name)
 {
-    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, parent_environment, private_environment, prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name));
+    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, parent_environment, private_environment, prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 ECMAScriptFunctionObject::ECMAScriptFunctionObject(DeprecatedFlyString name, DeprecatedString source_text, Statement const& ecmascript_code, Vector<FunctionParameter> formal_parameters, i32 function_length, Environment* parent_environment, PrivateEnvironment* private_environment, Object& prototype, FunctionKind kind, bool strict, bool might_need_arguments_object, bool contains_direct_call_to_eval, bool is_arrow_function, Variant<PropertyKey, PrivateName, Empty> class_field_initializer_name)
@@ -114,7 +114,7 @@ ThrowCompletionOr<void> ECMAScriptFunctionObject::initialize(Realm& realm)
         Object* prototype = nullptr;
         switch (m_kind) {
         case FunctionKind::Normal:
-            prototype = vm.heap().allocate<Object>(realm, *realm.intrinsics().new_ordinary_function_prototype_object_shape());
+            prototype = MUST_OR_THROW_OOM(vm.heap().allocate<Object>(realm, *realm.intrinsics().new_ordinary_function_prototype_object_shape()));
             MUST(prototype->define_property_or_throw(vm.names.constructor, { .value = this, .writable = true, .enumerable = false, .configurable = true }));
             break;
         case FunctionKind::Generator:

Userland/Libraries/LibJS/Runtime/Error.cpp

@@ -16,7 +16,7 @@ namespace JS {
 
 NonnullGCPtr<Error> Error::create(Realm& realm)
 {
-    return realm.heap().allocate<Error>(realm, *realm.intrinsics().error_prototype());
+    return realm.heap().allocate<Error>(realm, *realm.intrinsics().error_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NonnullGCPtr<Error> Error::create(Realm& realm, DeprecatedString const& message)
@@ -98,24 +98,24 @@ DeprecatedString Error::stack_string() const
     return stack_string_builder.to_deprecated_string();
 }
 
-#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType)              \
-    NonnullGCPtr<ClassName> ClassName::create(Realm& realm)                                           \
-    {                                                                                                 \
-        return realm.heap().allocate<ClassName>(realm, *realm.intrinsics().snake_name##_prototype()); \
-    }                                                                                                 \
-                                                                                                      \
-    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, DeprecatedString const& message)          \
-    {                                                                                                 \
-        auto& vm = realm.vm();                                                                        \
-        auto error = ClassName::create(realm);                                                        \
-        u8 attr = Attribute::Writable | Attribute::Configurable;                                      \
-        error->define_direct_property(vm.names.message, PrimitiveString::create(vm, message), attr);  \
-        return error;                                                                                 \
-    }                                                                                                 \
-                                                                                                      \
-    ClassName::ClassName(Object& prototype)                                                           \
-        : Error(prototype)                                                                            \
-    {                                                                                                 \
+#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType)                                                                          \
+    NonnullGCPtr<ClassName> ClassName::create(Realm& realm)                                                                                                       \
+    {                                                                                                                                                             \
+        return realm.heap().allocate<ClassName>(realm, *realm.intrinsics().snake_name##_prototype()).release_allocated_value_but_fixme_should_propagate_errors(); \
+    }                                                                                                                                                             \
+                                                                                                                                                                  \
+    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, DeprecatedString const& message)                                                                      \
+    {                                                                                                                                                             \
+        auto& vm = realm.vm();                                                                                                                                    \
+        auto error = ClassName::create(realm);                                                                                                                    \
+        u8 attr = Attribute::Writable | Attribute::Configurable;                                                                                                  \
+        error->define_direct_property(vm.names.message, PrimitiveString::create(vm, message), attr);                                                              \
+        return error;                                                                                                                                             \
+    }                                                                                                                                                             \
+                                                                                                                                                                  \
+    ClassName::ClassName(Object& prototype)                                                                                                                       \
+        : Error(prototype)                                                                                                                                        \
+    {                                                                                                                                                             \
     }
 
 JS_ENUMERATE_NATIVE_ERRORS

Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp

@@ -28,7 +28,7 @@ ThrowCompletionOr<NonnullGCPtr<GeneratorObject>> GeneratorObject::create(Realm&
         generating_function_prototype = TRY(generating_function->get(vm.names.prototype));
     }
     auto* generating_function_prototype_object = TRY(generating_function_prototype.to_object(vm));
-    auto object = realm.heap().allocate<GeneratorObject>(realm, realm, *generating_function_prototype_object, move(execution_context));
+    auto object = MUST_OR_THROW_OOM(realm.heap().allocate<GeneratorObject>(realm, realm, *generating_function_prototype_object, move(execution_context)));
     object->m_generating_function = generating_function;
     object->m_frame = move(frame);
     object->m_previous_value = initial_value;

Userland/Libraries/LibJS/Runtime/Intl/CollatorCompareFunction.cpp

@@ -13,7 +13,7 @@ namespace JS::Intl {
 
 NonnullGCPtr<CollatorCompareFunction> CollatorCompareFunction::create(Realm& realm, Collator& collator)
 {
-    return realm.heap().allocate<CollatorCompareFunction>(realm, realm, collator);
+    return realm.heap().allocate<CollatorCompareFunction>(realm, realm, collator).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CollatorCompareFunction::CollatorCompareFunction(Realm& realm, Collator& collator)

Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatFunction.cpp

@@ -16,7 +16,7 @@ namespace JS::Intl {
 // 11.5.5 DateTime Format Functions, https://tc39.es/ecma402/#sec-datetime-format-functions
 NonnullGCPtr<DateTimeFormatFunction> DateTimeFormatFunction::create(Realm& realm, DateTimeFormat& date_time_format)
 {
-    return realm.heap().allocate<DateTimeFormatFunction>(realm, date_time_format, *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<DateTimeFormatFunction>(realm, date_time_format, *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 DateTimeFormatFunction::DateTimeFormatFunction(DateTimeFormat& date_time_format, Object& prototype)

Userland/Libraries/LibJS/Runtime/Intl/Locale.cpp

@@ -16,7 +16,7 @@ namespace JS::Intl {
 
 ThrowCompletionOr<NonnullGCPtr<Locale>> Locale::create(Realm& realm, ::Locale::LocaleID locale_id)
 {
-    auto locale = realm.heap().allocate<Locale>(realm, *realm.intrinsics().intl_locale_prototype());
+    auto locale = MUST_OR_THROW_OOM(realm.heap().allocate<Locale>(realm, *realm.intrinsics().intl_locale_prototype()));
     locale->set_locale(TRY_OR_THROW_OOM(realm.vm(), locale_id.to_string()));
 
     for (auto& extension : locale_id.extensions) {

Userland/Libraries/LibJS/Runtime/Intl/NumberFormatFunction.cpp

@@ -14,7 +14,7 @@ namespace JS::Intl {
 // 1.5.2 Number Format Functions, https://tc39.es/proposal-intl-numberformat-v3/out/numberformat/proposed.html#sec-number-format-functions
 NonnullGCPtr<NumberFormatFunction> NumberFormatFunction::create(Realm& realm, NumberFormat& number_format)
 {
-    return realm.heap().allocate<NumberFormatFunction>(realm, number_format, *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<NumberFormatFunction>(realm, number_format, *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NumberFormatFunction::NumberFormatFunction(NumberFormat& number_format, Object& prototype)

Userland/Libraries/LibJS/Runtime/Intl/SegmentIterator.cpp

@@ -19,7 +19,7 @@ NonnullGCPtr<SegmentIterator> SegmentIterator::create(Realm& realm, Segmenter& s
     // 4. Set iterator.[[IteratedString]] to string.
     // 5. Set iterator.[[IteratedStringNextSegmentCodeUnitIndex]] to 0.
     // 6. Return iterator.
-    return realm.heap().allocate<SegmentIterator>(realm, realm, segmenter, move(string), segments);
+    return realm.heap().allocate<SegmentIterator>(realm, realm, segmenter, move(string), segments).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 // 18.6 Segment Iterator Objects, https://tc39.es/ecma402/#sec-segment-iterator-objects

Userland/Libraries/LibJS/Runtime/Intl/Segments.cpp

@@ -18,7 +18,7 @@ NonnullGCPtr<Segments> Segments::create(Realm& realm, Segmenter& segmenter, Utf1
     // 3. Set segments.[[SegmentsSegmenter]] to segmenter.
     // 4. Set segments.[[SegmentsString]] to string.
     // 5. Return segments.
-    return realm.heap().allocate<Segments>(realm, realm, segmenter, move(string));
+    return realm.heap().allocate<Segments>(realm, realm, segmenter, move(string)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 // 18.5 Segments Objects, https://tc39.es/ecma402/#sec-segments-objects

Userland/Libraries/LibJS/Runtime/Intrinsics.cpp

@@ -189,26 +189,26 @@ void Intrinsics::initialize_intrinsics(Realm& realm)
 
 #define __JS_ENUMERATE(ClassName, snake_name) \
     VERIFY(!m_##snake_name##_prototype);      \
-    m_##snake_name##_prototype = heap().allocate<ClassName##Prototype>(realm, realm);
+    m_##snake_name##_prototype = heap().allocate<ClassName##Prototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
     JS_ENUMERATE_ITERATOR_PROTOTYPES
 #undef __JS_ENUMERATE
 
     // These must be initialized separately as they have no companion constructor
-    m_async_from_sync_iterator_prototype = heap().allocate<AsyncFromSyncIteratorPrototype>(realm, realm);
-    m_async_generator_prototype = heap().allocate<AsyncGeneratorPrototype>(realm, realm);
-    m_generator_prototype = heap().allocate<GeneratorPrototype>(realm, realm);
-    m_intl_segments_prototype = heap().allocate<Intl::SegmentsPrototype>(realm, realm);
+    m_async_from_sync_iterator_prototype = heap().allocate<AsyncFromSyncIteratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_async_generator_prototype = heap().allocate<AsyncGeneratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_generator_prototype = heap().allocate<GeneratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_intl_segments_prototype = heap().allocate<Intl::SegmentsPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 
     // These must be initialized before allocating...
     // - AggregateErrorPrototype, which uses ErrorPrototype as its prototype
     // - AggregateErrorConstructor, which uses ErrorConstructor as its prototype
     // - AsyncFunctionConstructor, which uses FunctionConstructor as its prototype
-    m_error_prototype = heap().allocate<ErrorPrototype>(realm, realm);
-    m_error_constructor = heap().allocate<ErrorConstructor>(realm, realm);
-    m_function_constructor = heap().allocate<FunctionConstructor>(realm, realm);
+    m_error_prototype = heap().allocate<ErrorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_error_constructor = heap().allocate<ErrorConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_function_constructor = heap().allocate<FunctionConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 
     // Not included in JS_ENUMERATE_NATIVE_OBJECTS due to missing distinct prototype
-    m_proxy_constructor = heap().allocate<ProxyConstructor>(realm, realm);
+    m_proxy_constructor = heap().allocate<ProxyConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 
     // Global object functions
     m_eval_function = NativeFunction::create(realm, GlobalObject::eval, 1, vm.names.eval, &realm);
@@ -223,7 +223,7 @@ void Intrinsics::initialize_intrinsics(Realm& realm)
     m_escape_function = NativeFunction::create(realm, GlobalObject::escape, 1, vm.names.escape, &realm);
     m_unescape_function = NativeFunction::create(realm, GlobalObject::unescape, 1, vm.names.unescape, &realm);
 
-    m_object_constructor = heap().allocate<ObjectConstructor>(realm, realm);
+    m_object_constructor = heap().allocate<ObjectConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 
     // 10.2.4.1 %ThrowTypeError% ( ), https://tc39.es/ecma262/#sec-%throwtypeerror%
     m_throw_type_error_function = NativeFunction::create(
@@ -266,52 +266,52 @@ constexpr inline bool IsTypedArrayConstructor = false;
 JS_ENUMERATE_TYPED_ARRAYS
 #undef __JS_ENUMERATE
 
-#define __JS_ENUMERATE_INNER(ClassName, snake_name, PrototypeName, ConstructorName, Namespace, snake_namespace)                                          \
-    void Intrinsics::initialize_##snake_namespace##snake_name()                                                                                          \
-    {                                                                                                                                                    \
-        auto& vm = this->vm();                                                                                                                           \
-                                                                                                                                                         \
-        VERIFY(!m_##snake_namespace##snake_name##_prototype);                                                                                            \
-        VERIFY(!m_##snake_namespace##snake_name##_constructor);                                                                                          \
-        if constexpr (IsTypedArrayConstructor<Namespace::ConstructorName>) {                                                                             \
-            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, *typed_array_prototype());                  \
-            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm, *typed_array_constructor());   \
-        } else {                                                                                                                                         \
-            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, m_realm);                                   \
-            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm);                               \
-        }                                                                                                                                                \
-                                                                                                                                                         \
-        /* FIXME: Add these special cases to JS_ENUMERATE_NATIVE_OBJECTS */                                                                              \
-        if constexpr (IsSame<Namespace::ConstructorName, BigIntConstructor>)                                                                             \
-            initialize_constructor(vm, vm.names.BigInt, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
-        else if constexpr (IsSame<Namespace::ConstructorName, BooleanConstructor>)                                                                       \
-            initialize_constructor(vm, vm.names.Boolean, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);   \
-        else if constexpr (IsSame<Namespace::ConstructorName, FunctionConstructor>)                                                                      \
-            initialize_constructor(vm, vm.names.Function, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);  \
-        else if constexpr (IsSame<Namespace::ConstructorName, NumberConstructor>)                                                                        \
-            initialize_constructor(vm, vm.names.Number, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
-        else if constexpr (IsSame<Namespace::ConstructorName, RegExpConstructor>)                                                                        \
-            initialize_constructor(vm, vm.names.RegExp, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
-        else if constexpr (IsSame<Namespace::ConstructorName, StringConstructor>)                                                                        \
-            initialize_constructor(vm, vm.names.String, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
-        else if constexpr (IsSame<Namespace::ConstructorName, SymbolConstructor>)                                                                        \
-            initialize_constructor(vm, vm.names.Symbol, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
-        else                                                                                                                                             \
-            initialize_constructor(vm, vm.names.ClassName, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype); \
-    }                                                                                                                                                    \
-                                                                                                                                                         \
-    Namespace::ConstructorName* Intrinsics::snake_namespace##snake_name##_constructor()                                                                  \
-    {                                                                                                                                                    \
-        if (!m_##snake_namespace##snake_name##_constructor)                                                                                              \
-            initialize_##snake_namespace##snake_name();                                                                                                  \
-        return m_##snake_namespace##snake_name##_constructor;                                                                                            \
-    }                                                                                                                                                    \
-                                                                                                                                                         \
-    Object* Intrinsics::snake_namespace##snake_name##_prototype()                                                                                        \
-    {                                                                                                                                                    \
-        if (!m_##snake_namespace##snake_name##_prototype)                                                                                                \
-            initialize_##snake_namespace##snake_name();                                                                                                  \
-        return m_##snake_namespace##snake_name##_prototype;                                                                                              \
+#define __JS_ENUMERATE_INNER(ClassName, snake_name, PrototypeName, ConstructorName, Namespace, snake_namespace)                                                                                                    \
+    void Intrinsics::initialize_##snake_namespace##snake_name()                                                                                                                                                    \
+    {                                                                                                                                                                                                              \
+        auto& vm = this->vm();                                                                                                                                                                                     \
+                                                                                                                                                                                                                   \
+        VERIFY(!m_##snake_namespace##snake_name##_prototype);                                                                                                                                                      \
+        VERIFY(!m_##snake_namespace##snake_name##_constructor);                                                                                                                                                    \
+        if constexpr (IsTypedArrayConstructor<Namespace::ConstructorName>) {                                                                                                                                       \
+            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, *typed_array_prototype()).release_allocated_value_but_fixme_should_propagate_errors();                \
+            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm, *typed_array_constructor()).release_allocated_value_but_fixme_should_propagate_errors(); \
+        } else {                                                                                                                                                                                                   \
+            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, m_realm).release_allocated_value_but_fixme_should_propagate_errors();                                 \
+            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm).release_allocated_value_but_fixme_should_propagate_errors();                             \
+        }                                                                                                                                                                                                          \
+                                                                                                                                                                                                                   \
+        /* FIXME: Add these special cases to JS_ENUMERATE_NATIVE_OBJECTS */                                                                                                                                        \
+        if constexpr (IsSame<Namespace::ConstructorName, BigIntConstructor>)                                                                                                                                       \
+            initialize_constructor(vm, vm.names.BigInt, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
+        else if constexpr (IsSame<Namespace::ConstructorName, BooleanConstructor>)                                                                                                                                 \
+            initialize_constructor(vm, vm.names.Boolean, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                             \
+        else if constexpr (IsSame<Namespace::ConstructorName, FunctionConstructor>)                                                                                                                                \
+            initialize_constructor(vm, vm.names.Function, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                            \
+        else if constexpr (IsSame<Namespace::ConstructorName, NumberConstructor>)                                                                                                                                  \
+            initialize_constructor(vm, vm.names.Number, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
+        else if constexpr (IsSame<Namespace::ConstructorName, RegExpConstructor>)                                                                                                                                  \
+            initialize_constructor(vm, vm.names.RegExp, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
+        else if constexpr (IsSame<Namespace::ConstructorName, StringConstructor>)                                                                                                                                  \
+            initialize_constructor(vm, vm.names.String, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
+        else if constexpr (IsSame<Namespace::ConstructorName, SymbolConstructor>)                                                                                                                                  \
+            initialize_constructor(vm, vm.names.Symbol, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
+        else                                                                                                                                                                                                       \
+            initialize_constructor(vm, vm.names.ClassName, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                           \
+    }                                                                                                                                                                                                              \
+                                                                                                                                                                                                                   \
+    Namespace::ConstructorName* Intrinsics::snake_namespace##snake_name##_constructor()                                                                                                                            \
+    {                                                                                                                                                                                                              \
+        if (!m_##snake_namespace##snake_name##_constructor)                                                                                                                                                        \
+            initialize_##snake_namespace##snake_name();                                                                                                                                                            \
+        return m_##snake_namespace##snake_name##_constructor;                                                                                                                                                      \
+    }                                                                                                                                                                                                              \
+                                                                                                                                                                                                                   \
+    Object* Intrinsics::snake_namespace##snake_name##_prototype()                                                                                                                                                  \
+    {                                                                                                                                                                                                              \
+        if (!m_##snake_namespace##snake_name##_prototype)                                                                                                                                                          \
+            initialize_##snake_namespace##snake_name();                                                                                                                                                            \
+        return m_##snake_namespace##snake_name##_prototype;                                                                                                                                                        \
     }
 
 #define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType) \
@@ -331,12 +331,12 @@ JS_ENUMERATE_TEMPORAL_OBJECTS
 
 #undef __JS_ENUMERATE_INNER
 
-#define __JS_ENUMERATE(ClassName, snake_name)                                       \
-    ClassName* Intrinsics::snake_name##_object()                                    \
-    {                                                                               \
-        if (!m_##snake_name##_object)                                               \
-            m_##snake_name##_object = heap().allocate<ClassName>(m_realm, m_realm); \
-        return m_##snake_name##_object;                                             \
+#define __JS_ENUMERATE(ClassName, snake_name)                                                                                                   \
+    ClassName* Intrinsics::snake_name##_object()                                                                                                \
+    {                                                                                                                                           \
+        if (!m_##snake_name##_object)                                                                                                           \
+            m_##snake_name##_object = heap().allocate<ClassName>(m_realm, m_realm).release_allocated_value_but_fixme_should_propagate_errors(); \
+        return m_##snake_name##_object;                                                                                                         \
     }
 JS_ENUMERATE_BUILTIN_NAMESPACE_OBJECTS
 #undef __JS_ENUMERATE

Userland/Libraries/LibJS/Runtime/Map.cpp

@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<Map> Map::create(Realm& realm)
 {
-    return realm.heap().allocate<Map>(realm, *realm.intrinsics().map_prototype());
+    return realm.heap().allocate<Map>(realm, *realm.intrinsics().map_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Map::Map(Object& prototype)

Userland/Libraries/LibJS/Runtime/MapIterator.cpp

@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<MapIterator> MapIterator::create(Realm& realm, Map& map, Object::PropertyKind iteration_kind)
 {
-    return realm.heap().allocate<MapIterator>(realm, map, iteration_kind, *realm.intrinsics().map_iterator_prototype());
+    return realm.heap().allocate<MapIterator>(realm, map, iteration_kind, *realm.intrinsics().map_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 MapIterator::MapIterator(Map& map, Object::PropertyKind iteration_kind, Object& prototype)

Userland/Libraries/LibJS/Runtime/NativeFunction.cpp

@@ -36,7 +36,7 @@ NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, Saf
     // 7. Set func.[[Extensible]] to true.
     // 8. Set func.[[Realm]] to realm.
     // 9. Set func.[[InitialName]] to null.
-    auto function = allocating_realm.heap().allocate<NativeFunction>(allocating_realm, move(behaviour), prototype.value(), *realm.value());
+    auto function = allocating_realm.heap().allocate<NativeFunction>(allocating_realm, move(behaviour), prototype.value(), *realm.value()).release_allocated_value_but_fixme_should_propagate_errors();
 
     // 10. Perform SetFunctionLength(func, length).
     function->set_function_length(length);
@@ -53,7 +53,7 @@ NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, Saf
 
 NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& realm, DeprecatedFlyString const& name, SafeFunction<ThrowCompletionOr<Value>(VM&)> function)
 {
-    return realm.heap().allocate<NativeFunction>(realm, name, move(function), *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<NativeFunction>(realm, name, move(function), *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NativeFunction::NativeFunction(SafeFunction<ThrowCompletionOr<Value>(VM&)> native_function, Object* prototype, Realm& realm)

Userland/Libraries/LibJS/Runtime/NumberObject.cpp

@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<NumberObject> NumberObject::create(Realm& realm, double value)
 {
-    return realm.heap().allocate<NumberObject>(realm, value, *realm.intrinsics().number_prototype());
+    return realm.heap().allocate<NumberObject>(realm, value, *realm.intrinsics().number_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NumberObject::NumberObject(double value, Object& prototype)

Userland/Libraries/LibJS/Runtime/Object.cpp

@@ -30,11 +30,10 @@ static HashMap<Object const*, HashMap<DeprecatedFlyString, Object::IntrinsicAcce
 NonnullGCPtr<Object> Object::create(Realm& realm, Object* prototype)
 {
     if (!prototype)
-        return realm.heap().allocate<Object>(realm, *realm.intrinsics().empty_object_shape());
-    else if (prototype == realm.intrinsics().object_prototype())
-        return realm.heap().allocate<Object>(realm, *realm.intrinsics().new_object_shape());
-    else
-        return realm.heap().allocate<Object>(realm, ConstructWithPrototypeTag::Tag, *prototype);
+        return realm.heap().allocate<Object>(realm, *realm.intrinsics().empty_object_shape()).release_allocated_value_but_fixme_should_propagate_errors();
+    if (prototype == realm.intrinsics().object_prototype())
+        return realm.heap().allocate<Object>(realm, *realm.intrinsics().new_object_shape()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<Object>(realm, ConstructWithPrototypeTag::Tag, *prototype).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Object::Object(GlobalObjectTag, Realm& realm)

Userland/Libraries/LibJS/Runtime/Promise.cpp

@@ -44,7 +44,7 @@ ThrowCompletionOr<Object*> promise_resolve(VM& vm, Object& constructor, Value va
 
 NonnullGCPtr<Promise> Promise::create(Realm& realm)
 {
-    return realm.heap().allocate<Promise>(realm, *realm.intrinsics().promise_prototype());
+    return realm.heap().allocate<Promise>(realm, *realm.intrinsics().promise_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 // 27.2 Promise Objects, https://tc39.es/ecma262/#sec-promise-objects

Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.cpp

@@ -57,7 +57,7 @@ void PromiseResolvingElementFunction::visit_edges(Cell::Visitor& visitor)
 
 NonnullGCPtr<PromiseAllResolveElementFunction> PromiseAllResolveElementFunction::create(Realm& realm, size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAllResolveElementFunction>(realm, index, values, capability, remaining_elements, *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<PromiseAllResolveElementFunction>(realm, index, values, capability, remaining_elements, *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 PromiseAllResolveElementFunction::PromiseAllResolveElementFunction(size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements, Object& prototype)
@@ -89,7 +89,7 @@ ThrowCompletionOr<Value> PromiseAllResolveElementFunction::resolve_element()
 
 NonnullGCPtr<PromiseAllSettledResolveElementFunction> PromiseAllSettledResolveElementFunction::create(Realm& realm, size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAllSettledResolveElementFunction>(realm, index, values, capability, remaining_elements, *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<PromiseAllSettledResolveElementFunction>(realm, index, values, capability, remaining_elements, *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 PromiseAllSettledResolveElementFunction::PromiseAllSettledResolveElementFunction(size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements, Object& prototype)
@@ -130,7 +130,7 @@ ThrowCompletionOr<Value> PromiseAllSettledResolveElementFunction::resolve_elemen
 
 NonnullGCPtr<PromiseAllSettledRejectElementFunction> PromiseAllSettledRejectElementFunction::create(Realm& realm, size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAllSettledRejectElementFunction>(realm, index, values, capability, remaining_elements, *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<PromiseAllSettledRejectElementFunction>(realm, index, values, capability, remaining_elements, *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 PromiseAllSettledRejectElementFunction::PromiseAllSettledRejectElementFunction(size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements, Object& prototype)
@@ -171,7 +171,7 @@ ThrowCompletionOr<Value> PromiseAllSettledRejectElementFunction::resolve_element
 
 NonnullGCPtr<PromiseAnyRejectElementFunction> PromiseAnyRejectElementFunction::create(Realm& realm, size_t index, PromiseValueList& errors, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAnyRejectElementFunction>(realm, index, errors, capability, remaining_elements, *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<PromiseAnyRejectElementFunction>(realm, index, errors, capability, remaining_elements, *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 PromiseAnyRejectElementFunction::PromiseAnyRejectElementFunction(size_t index, PromiseValueList& errors, NonnullGCPtr<PromiseCapability> capability, RemainingElements& remaining_elements, Object& prototype)

Userland/Libraries/LibJS/Runtime/PromiseResolvingFunction.cpp

@@ -13,7 +13,7 @@ namespace JS {
 
 NonnullGCPtr<PromiseResolvingFunction> PromiseResolvingFunction::create(Realm& realm, Promise& promise, AlreadyResolved& already_resolved, FunctionType function)
 {
-    return realm.heap().allocate<PromiseResolvingFunction>(realm, promise, already_resolved, move(function), *realm.intrinsics().function_prototype());
+    return realm.heap().allocate<PromiseResolvingFunction>(realm, promise, already_resolved, move(function), *realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 PromiseResolvingFunction::PromiseResolvingFunction(Promise& promise, AlreadyResolved& already_resolved, FunctionType native_function, Object& prototype)

Userland/Libraries/LibJS/Runtime/ProxyObject.cpp

@@ -17,7 +17,7 @@ namespace JS {
 
 NonnullGCPtr<ProxyObject> ProxyObject::create(Realm& realm, Object& target, Object& handler)
 {
-    return realm.heap().allocate<ProxyObject>(realm, target, handler, *realm.intrinsics().object_prototype());
+    return realm.heap().allocate<ProxyObject>(realm, target, handler, *realm.intrinsics().object_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 ProxyObject::ProxyObject(Object& target, Object& handler, Object& prototype)

Userland/Libraries/LibJS/Runtime/RegExpObject.cpp

@@ -130,12 +130,12 @@ ThrowCompletionOr<DeprecatedString> parse_regex_pattern(VM& vm, StringView patte
 
 NonnullGCPtr<RegExpObject> RegExpObject::create(Realm& realm)
 {
-    return realm.heap().allocate<RegExpObject>(realm, *realm.intrinsics().regexp_prototype());
+    return realm.heap().allocate<RegExpObject>(realm, *realm.intrinsics().regexp_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NonnullGCPtr<RegExpObject> RegExpObject::create(Realm& realm, Regex<ECMA262> regex, DeprecatedString pattern, DeprecatedString flags)
 {
-    return realm.heap().allocate<RegExpObject>(realm, move(regex), move(pattern), move(flags), *realm.intrinsics().regexp_prototype());
+    return realm.heap().allocate<RegExpObject>(realm, move(regex), move(pattern), move(flags), *realm.intrinsics().regexp_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 RegExpObject::RegExpObject(Object& prototype)

Userland/Libraries/LibJS/Runtime/RegExpStringIterator.cpp

@@ -12,7 +12,7 @@ namespace JS {
 // 22.2.7.1 CreateRegExpStringIterator ( R, S, global, fullUnicode ), https://tc39.es/ecma262/#sec-createregexpstringiterator
 NonnullGCPtr<RegExpStringIterator> RegExpStringIterator::create(Realm& realm, Object& regexp_object, Utf16String string, bool global, bool unicode)
 {
-    return realm.heap().allocate<RegExpStringIterator>(realm, *realm.intrinsics().regexp_string_iterator_prototype(), regexp_object, move(string), global, unicode);
+    return realm.heap().allocate<RegExpStringIterator>(realm, *realm.intrinsics().regexp_string_iterator_prototype(), regexp_object, move(string), global, unicode).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 RegExpStringIterator::RegExpStringIterator(Object& prototype, Object& regexp_object, Utf16String string, bool global, bool unicode)

Userland/Libraries/LibJS/Runtime/Set.cpp

@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<Set> Set::create(Realm& realm)
 {
-    return realm.heap().allocate<Set>(realm, *realm.intrinsics().set_prototype());
+    return realm.heap().allocate<Set>(realm, *realm.intrinsics().set_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Set::Set(Object& prototype)

Userland/Libraries/LibJS/Runtime/SetIterator.cpp

@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<SetIterator> SetIterator::create(Realm& realm, Set& set, Object::PropertyKind iteration_kind)
 {
-    return realm.heap().allocate<SetIterator>(realm, set, iteration_kind, *realm.intrinsics().set_iterator_prototype());
+    return realm.heap().allocate<SetIterator>(realm, set, iteration_kind, *realm.intrinsics().set_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 SetIterator::SetIterator(Set& set, Object::PropertyKind iteration_kind, Object& prototype)

Userland/Libraries/LibJS/Runtime/StringIterator.cpp

@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<StringIterator> StringIterator::create(Realm& realm, String string)
 {
-    return realm.heap().allocate<StringIterator>(realm, move(string), *realm.intrinsics().string_iterator_prototype());
+    return realm.heap().allocate<StringIterator>(realm, move(string), *realm.intrinsics().string_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 StringIterator::StringIterator(String string, Object& prototype)

Userland/Libraries/LibJS/Runtime/StringObject.cpp

@@ -17,7 +17,7 @@ namespace JS {
 // 10.4.3.4 StringCreate ( value, prototype ), https://tc39.es/ecma262/#sec-stringcreate
 NonnullGCPtr<StringObject> StringObject::create(Realm& realm, PrimitiveString& primitive_string, Object& prototype)
 {
-    return realm.heap().allocate<StringObject>(realm, primitive_string, prototype);
+    return realm.heap().allocate<StringObject>(realm, primitive_string, prototype).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 StringObject::StringObject(PrimitiveString& string, Object& prototype)

Userland/Libraries/LibJS/Runtime/SuppressedError.cpp

@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<SuppressedError> SuppressedError::create(Realm& realm)
 {
-    return *realm.heap().allocate<SuppressedError>(realm, *realm.intrinsics().suppressed_error_prototype());
+    return *realm.heap().allocate<SuppressedError>(realm, *realm.intrinsics().suppressed_error_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 SuppressedError::SuppressedError(Object& prototype)

Userland/Libraries/LibJS/Runtime/SymbolObject.cpp

@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<SymbolObject> SymbolObject::create(Realm& realm, Symbol& primitive_symbol)
 {
-    return realm.heap().allocate<SymbolObject>(realm, primitive_symbol, *realm.intrinsics().symbol_prototype());
+    return realm.heap().allocate<SymbolObject>(realm, primitive_symbol, *realm.intrinsics().symbol_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 SymbolObject::SymbolObject(Symbol& symbol, Object& prototype)

Userland/Libraries/LibJS/Runtime/Temporal/Temporal.cpp

@@ -36,7 +36,7 @@ ThrowCompletionOr<void> Temporal::initialize(Realm& realm)
     define_direct_property(*vm.well_known_symbol_to_string_tag(), PrimitiveString::create(vm, "Temporal"), Attribute::Configurable);
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
-    define_direct_property(vm.names.Now, heap().allocate<Now>(realm, realm), attr);
+    define_direct_property(vm.names.Now, MUST_OR_THROW_OOM(heap().allocate<Now>(realm, realm)), attr);
     define_intrinsic_accessor(vm.names.Calendar, attr, [](auto& realm) -> Value { return realm.intrinsics().temporal_calendar_constructor(); });
     define_intrinsic_accessor(vm.names.Duration, attr, [](auto& realm) -> Value { return realm.intrinsics().temporal_duration_constructor(); });
     define_intrinsic_accessor(vm.names.Instant, attr, [](auto& realm) -> Value { return realm.intrinsics().temporal_instant_constructor(); });

Userland/Libraries/LibJS/Runtime/TypedArray.cpp

@@ -420,141 +420,141 @@ void TypedArrayBase::visit_edges(Visitor& visitor)
     visitor.visit(m_viewed_array_buffer);
 }
 
-#define JS_DEFINE_TYPED_ARRAY(ClassName, snake_name, PrototypeName, ConstructorName, Type)                                       \
-    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length, FunctionObject& new_target)           \
-    {                                                                                                                            \
-        auto* prototype = TRY(get_prototype_from_constructor(realm.vm(), new_target, &Intrinsics::snake_name##_prototype));      \
-        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                          \
-        return realm.heap().allocate<ClassName>(realm, *prototype, length, *array_buffer);                                       \
-    }                                                                                                                            \
-                                                                                                                                 \
-    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length)                                       \
-    {                                                                                                                            \
-        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                          \
-        return create(realm, length, *array_buffer);                                                                             \
-    }                                                                                                                            \
-                                                                                                                                 \
-    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, u32 length, ArrayBuffer& array_buffer)                               \
-    {                                                                                                                            \
-        return realm.heap().allocate<ClassName>(realm, *realm.intrinsics().snake_name##_prototype(), length, array_buffer);      \
-    }                                                                                                                            \
-                                                                                                                                 \
-    ClassName::ClassName(Object& prototype, u32 length, ArrayBuffer& array_buffer)                                               \
-        : TypedArray(prototype,                                                                                                  \
-            reinterpret_cast<TypedArrayBase::IntrinsicConstructor>(&Intrinsics::snake_name##_constructor), length, array_buffer) \
-    {                                                                                                                            \
-        if constexpr (#ClassName##sv.is_one_of("BigInt64Array", "BigUint64Array"))                                               \
-            m_content_type = ContentType::BigInt;                                                                                \
-        else                                                                                                                     \
-            m_content_type = ContentType::Number;                                                                                \
-    }                                                                                                                            \
-                                                                                                                                 \
-    ClassName::~ClassName()                                                                                                      \
-    {                                                                                                                            \
-    }                                                                                                                            \
-                                                                                                                                 \
-    DeprecatedFlyString const& ClassName::element_name() const                                                                   \
-    {                                                                                                                            \
-        return vm().names.ClassName.as_string();                                                                                 \
-    }                                                                                                                            \
-                                                                                                                                 \
-    PrototypeName::PrototypeName(Object& prototype)                                                                              \
-        : Object(ConstructWithPrototypeTag::Tag, prototype)                                                                      \
-    {                                                                                                                            \
-    }                                                                                                                            \
-                                                                                                                                 \
-    PrototypeName::~PrototypeName()                                                                                              \
-    {                                                                                                                            \
-    }                                                                                                                            \
-                                                                                                                                 \
-    ThrowCompletionOr<void> PrototypeName::initialize(Realm& realm)                                                              \
-    {                                                                                                                            \
-        auto& vm = this->vm();                                                                                                   \
-        MUST_OR_THROW_OOM(Base::initialize(realm));                                                                              \
-        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                         \
-                                                                                                                                 \
-        return {};                                                                                                               \
-    }                                                                                                                            \
-                                                                                                                                 \
-    ConstructorName::ConstructorName(Realm& realm, Object& prototype)                                                            \
-        : TypedArrayConstructor(realm.vm().names.ClassName.as_string(), prototype)                                               \
-    {                                                                                                                            \
-    }                                                                                                                            \
-                                                                                                                                 \
-    ConstructorName::~ConstructorName()                                                                                          \
-    {                                                                                                                            \
-    }                                                                                                                            \
-                                                                                                                                 \
-    ThrowCompletionOr<void> ConstructorName::initialize(Realm& realm)                                                            \
-    {                                                                                                                            \
-        auto& vm = this->vm();                                                                                                   \
-        MUST_OR_THROW_OOM(NativeFunction::initialize(realm));                                                                    \
-                                                                                                                                 \
-        /* 23.2.6.2 TypedArray.prototype, https://tc39.es/ecma262/#sec-typedarray.prototype */                                   \
-        define_direct_property(vm.names.prototype, realm.intrinsics().snake_name##_prototype(), 0);                              \
-                                                                                                                                 \
-        /* 23.2.6.1 TypedArray.BYTES_PER_ELEMENT, https://tc39.es/ecma262/#sec-typedarray.bytes_per_element */                   \
-        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                         \
-                                                                                                                                 \
-        define_direct_property(vm.names.length, Value(3), Attribute::Configurable);                                              \
-                                                                                                                                 \
-        return {};                                                                                                               \
-    }                                                                                                                            \
-                                                                                                                                 \
-    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                               \
-    ThrowCompletionOr<Value> ConstructorName::call()                                                                             \
-    {                                                                                                                            \
-        auto& vm = this->vm();                                                                                                   \
-        return vm.throw_completion<TypeError>(ErrorType::ConstructorWithoutNew, vm.names.ClassName);                             \
-    }                                                                                                                            \
-                                                                                                                                 \
-    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                               \
-    ThrowCompletionOr<NonnullGCPtr<Object>> ConstructorName::construct(FunctionObject& new_target)                               \
-    {                                                                                                                            \
-        auto& vm = this->vm();                                                                                                   \
-        auto& realm = *vm.current_realm();                                                                                       \
-                                                                                                                                 \
-        if (vm.argument_count() == 0)                                                                                            \
-            return TRY(ClassName::create(realm, 0, new_target));                                                                 \
-                                                                                                                                 \
-        auto first_argument = vm.argument(0);                                                                                    \
-        if (first_argument.is_object()) {                                                                                        \
-            auto typed_array = TRY(ClassName::create(realm, 0, new_target));                                                     \
-            if (first_argument.as_object().is_typed_array()) {                                                                   \
-                auto& arg_typed_array = static_cast<TypedArrayBase&>(first_argument.as_object());                                \
-                TRY(initialize_typed_array_from_typed_array(vm, *typed_array, arg_typed_array));                                 \
-            } else if (is<ArrayBuffer>(first_argument.as_object())) {                                                            \
-                auto& array_buffer = static_cast<ArrayBuffer&>(first_argument.as_object());                                      \
-                TRY(initialize_typed_array_from_array_buffer(vm, *typed_array, array_buffer,                                     \
-                    vm.argument(1), vm.argument(2)));                                                                            \
-            } else {                                                                                                             \
-                auto iterator = TRY(first_argument.get_method(vm, *vm.well_known_symbol_iterator()));                            \
-                if (iterator) {                                                                                                  \
-                    auto values = TRY(iterable_to_list(vm, first_argument, iterator));                                           \
-                    TRY(initialize_typed_array_from_list(vm, *typed_array, values));                                             \
-                } else {                                                                                                         \
-                    TRY(initialize_typed_array_from_array_like(vm, *typed_array, first_argument.as_object()));                   \
-                }                                                                                                                \
-            }                                                                                                                    \
-            return typed_array;                                                                                                  \
-        }                                                                                                                        \
-                                                                                                                                 \
-        auto array_length_or_error = first_argument.to_index(vm);                                                                \
-        if (array_length_or_error.is_error()) {                                                                                  \
-            auto error = array_length_or_error.release_error();                                                                  \
-            if (error.value()->is_object() && is<RangeError>(error.value()->as_object())) {                                      \
-                /* Re-throw more specific RangeError */                                                                          \
-                return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                 \
-            }                                                                                                                    \
-            return error;                                                                                                        \
-        }                                                                                                                        \
-        auto array_length = array_length_or_error.release_value();                                                               \
-        if (array_length > NumericLimits<i32>::max() / sizeof(Type))                                                             \
-            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                     \
-        /* FIXME: What is the best/correct behavior here? */                                                                     \
-        if (Checked<u32>::multiplication_would_overflow(array_length, sizeof(Type)))                                             \
-            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                     \
-        return TRY(ClassName::create(realm, array_length, new_target));                                                          \
+#define JS_DEFINE_TYPED_ARRAY(ClassName, snake_name, PrototypeName, ConstructorName, Type)                                                                                              \
+    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length, FunctionObject& new_target)                                                                  \
+    {                                                                                                                                                                                   \
+        auto* prototype = TRY(get_prototype_from_constructor(realm.vm(), new_target, &Intrinsics::snake_name##_prototype));                                                             \
+        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                                                                                 \
+        return MUST_OR_THROW_OOM(realm.heap().allocate<ClassName>(realm, *prototype, length, *array_buffer));                                                                           \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length)                                                                                              \
+    {                                                                                                                                                                                   \
+        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                                                                                 \
+        return create(realm, length, *array_buffer);                                                                                                                                    \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, u32 length, ArrayBuffer& array_buffer)                                                                                      \
+    {                                                                                                                                                                                   \
+        return realm.heap().allocate<ClassName>(realm, *realm.intrinsics().snake_name##_prototype(), length, array_buffer).release_allocated_value_but_fixme_should_propagate_errors(); \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    ClassName::ClassName(Object& prototype, u32 length, ArrayBuffer& array_buffer)                                                                                                      \
+        : TypedArray(prototype,                                                                                                                                                         \
+            reinterpret_cast<TypedArrayBase::IntrinsicConstructor>(&Intrinsics::snake_name##_constructor), length, array_buffer)                                                        \
+    {                                                                                                                                                                                   \
+        if constexpr (#ClassName##sv.is_one_of("BigInt64Array", "BigUint64Array"))                                                                                                      \
+            m_content_type = ContentType::BigInt;                                                                                                                                       \
+        else                                                                                                                                                                            \
+            m_content_type = ContentType::Number;                                                                                                                                       \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    ClassName::~ClassName()                                                                                                                                                             \
+    {                                                                                                                                                                                   \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    DeprecatedFlyString const& ClassName::element_name() const                                                                                                                          \
+    {                                                                                                                                                                                   \
+        return vm().names.ClassName.as_string();                                                                                                                                        \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    PrototypeName::PrototypeName(Object& prototype)                                                                                                                                     \
+        : Object(ConstructWithPrototypeTag::Tag, prototype)                                                                                                                             \
+    {                                                                                                                                                                                   \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    PrototypeName::~PrototypeName()                                                                                                                                                     \
+    {                                                                                                                                                                                   \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    ThrowCompletionOr<void> PrototypeName::initialize(Realm& realm)                                                                                                                     \
+    {                                                                                                                                                                                   \
+        auto& vm = this->vm();                                                                                                                                                          \
+        MUST_OR_THROW_OOM(Base::initialize(realm));                                                                                                                                     \
+        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                                                                                \
+                                                                                                                                                                                        \
+        return {};                                                                                                                                                                      \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    ConstructorName::ConstructorName(Realm& realm, Object& prototype)                                                                                                                   \
+        : TypedArrayConstructor(realm.vm().names.ClassName.as_string(), prototype)                                                                                                      \
+    {                                                                                                                                                                                   \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    ConstructorName::~ConstructorName()                                                                                                                                                 \
+    {                                                                                                                                                                                   \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    ThrowCompletionOr<void> ConstructorName::initialize(Realm& realm)                                                                                                                   \
+    {                                                                                                                                                                                   \
+        auto& vm = this->vm();                                                                                                                                                          \
+        MUST_OR_THROW_OOM(NativeFunction::initialize(realm));                                                                                                                           \
+                                                                                                                                                                                        \
+        /* 23.2.6.2 TypedArray.prototype, https://tc39.es/ecma262/#sec-typedarray.prototype */                                                                                          \
+        define_direct_property(vm.names.prototype, realm.intrinsics().snake_name##_prototype(), 0);                                                                                     \
+                                                                                                                                                                                        \
+        /* 23.2.6.1 TypedArray.BYTES_PER_ELEMENT, https://tc39.es/ecma262/#sec-typedarray.bytes_per_element */                                                                          \
+        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                                                                                \
+                                                                                                                                                                                        \
+        define_direct_property(vm.names.length, Value(3), Attribute::Configurable);                                                                                                     \
+                                                                                                                                                                                        \
+        return {};                                                                                                                                                                      \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                                                                                      \
+    ThrowCompletionOr<Value> ConstructorName::call()                                                                                                                                    \
+    {                                                                                                                                                                                   \
+        auto& vm = this->vm();                                                                                                                                                          \
+        return vm.throw_completion<TypeError>(ErrorType::ConstructorWithoutNew, vm.names.ClassName);                                                                                    \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                                                                                      \
+    ThrowCompletionOr<NonnullGCPtr<Object>> ConstructorName::construct(FunctionObject& new_target)                                                                                      \
+    {                                                                                                                                                                                   \
+        auto& vm = this->vm();                                                                                                                                                          \
+        auto& realm = *vm.current_realm();                                                                                                                                              \
+                                                                                                                                                                                        \
+        if (vm.argument_count() == 0)                                                                                                                                                   \
+            return TRY(ClassName::create(realm, 0, new_target));                                                                                                                        \
+                                                                                                                                                                                        \
+        auto first_argument = vm.argument(0);                                                                                                                                           \
+        if (first_argument.is_object()) {                                                                                                                                               \
+            auto typed_array = TRY(ClassName::create(realm, 0, new_target));                                                                                                            \
+            if (first_argument.as_object().is_typed_array()) {                                                                                                                          \
+                auto& arg_typed_array = static_cast<TypedArrayBase&>(first_argument.as_object());                                                                                       \
+                TRY(initialize_typed_array_from_typed_array(vm, *typed_array, arg_typed_array));                                                                                        \
+            } else if (is<ArrayBuffer>(first_argument.as_object())) {                                                                                                                   \
+                auto& array_buffer = static_cast<ArrayBuffer&>(first_argument.as_object());                                                                                             \
+                TRY(initialize_typed_array_from_array_buffer(vm, *typed_array, array_buffer,                                                                                            \
+                    vm.argument(1), vm.argument(2)));                                                                                                                                   \
+            } else {                                                                                                                                                                    \
+                auto iterator = TRY(first_argument.get_method(vm, *vm.well_known_symbol_iterator()));                                                                                   \
+                if (iterator) {                                                                                                                                                         \
+                    auto values = TRY(iterable_to_list(vm, first_argument, iterator));                                                                                                  \
+                    TRY(initialize_typed_array_from_list(vm, *typed_array, values));                                                                                                    \
+                } else {                                                                                                                                                                \
+                    TRY(initialize_typed_array_from_array_like(vm, *typed_array, first_argument.as_object()));                                                                          \
+                }                                                                                                                                                                       \
+            }                                                                                                                                                                           \
+            return typed_array;                                                                                                                                                         \
+        }                                                                                                                                                                               \
+                                                                                                                                                                                        \
+        auto array_length_or_error = first_argument.to_index(vm);                                                                                                                       \
+        if (array_length_or_error.is_error()) {                                                                                                                                         \
+            auto error = array_length_or_error.release_error();                                                                                                                         \
+            if (error.value()->is_object() && is<RangeError>(error.value()->as_object())) {                                                                                             \
+                /* Re-throw more specific RangeError */                                                                                                                                 \
+                return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                                                                        \
+            }                                                                                                                                                                           \
+            return error;                                                                                                                                                               \
+        }                                                                                                                                                                               \
+        auto array_length = array_length_or_error.release_value();                                                                                                                      \
+        if (array_length > NumericLimits<i32>::max() / sizeof(Type))                                                                                                                    \
+            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                                                                            \
+        /* FIXME: What is the best/correct behavior here? */                                                                                                                            \
+        if (Checked<u32>::multiplication_would_overflow(array_length, sizeof(Type)))                                                                                                    \
+            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                                                                            \
+        return TRY(ClassName::create(realm, array_length, new_target));                                                                                                                 \
     }
 
 #undef __JS_ENUMERATE

Userland/Libraries/LibJS/Runtime/WeakMap.cpp

@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<WeakMap> WeakMap::create(Realm& realm)
 {
-    return realm.heap().allocate<WeakMap>(realm, *realm.intrinsics().weak_map_prototype());
+    return realm.heap().allocate<WeakMap>(realm, *realm.intrinsics().weak_map_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 WeakMap::WeakMap(Object& prototype)

Userland/Libraries/LibJS/Runtime/WeakRef.cpp

@@ -10,12 +10,12 @@ namespace JS {
 
 NonnullGCPtr<WeakRef> WeakRef::create(Realm& realm, Object& value)
 {
-    return realm.heap().allocate<WeakRef>(realm, value, *realm.intrinsics().weak_ref_prototype());
+    return realm.heap().allocate<WeakRef>(realm, value, *realm.intrinsics().weak_ref_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NonnullGCPtr<WeakRef> WeakRef::create(Realm& realm, Symbol& value)
 {
-    return realm.heap().allocate<WeakRef>(realm, value, *realm.intrinsics().weak_ref_prototype());
+    return realm.heap().allocate<WeakRef>(realm, value, *realm.intrinsics().weak_ref_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 WeakRef::WeakRef(Object& value, Object& prototype)

Userland/Libraries/LibJS/Runtime/WeakSet.cpp

@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<WeakSet> WeakSet::create(Realm& realm)
 {
-    return realm.heap().allocate<WeakSet>(realm, *realm.intrinsics().weak_set_prototype());
+    return realm.heap().allocate<WeakSet>(realm, *realm.intrinsics().weak_set_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 WeakSet::WeakSet(Object& prototype)

Userland/Libraries/LibJS/Runtime/WrappedFunction.cpp

@@ -22,7 +22,7 @@ ThrowCompletionOr<NonnullGCPtr<WrappedFunction>> WrappedFunction::create(Realm&
     // 5. Set wrapped.[[WrappedTargetFunction]] to Target.
     // 6. Set wrapped.[[Realm]] to callerRealm.
     auto& prototype = *caller_realm.intrinsics().function_prototype();
-    auto wrapped = vm.heap().allocate<WrappedFunction>(realm, caller_realm, target, prototype);
+    auto wrapped = MUST_OR_THROW_OOM(vm.heap().allocate<WrappedFunction>(realm, caller_realm, target, prototype));
 
     // 7. Let result be CopyNameAndLength(wrapped, Target).
     auto result = copy_name_and_length(vm, *wrapped, target);

Userland/Libraries/LibWeb/Bindings/MainThreadVM.cpp

@@ -375,7 +375,7 @@ JS::VM& main_thread_vm()
         custom_data.root_execution_context = MUST(JS::Realm::initialize_host_defined_realm(*vm, nullptr, nullptr));
 
         auto* root_realm = custom_data.root_execution_context->realm;
-        auto intrinsics = root_realm->heap().allocate<Intrinsics>(*root_realm, *root_realm);
+        auto intrinsics = root_realm->heap().allocate<Intrinsics>(*root_realm, *root_realm).release_allocated_value_but_fixme_should_propagate_errors();
         auto host_defined = make<HostDefined>(nullptr, intrinsics);
         root_realm->set_host_defined(move(host_defined));
         custom_data.internal_realm = root_realm;

Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp

@@ -53,7 +53,7 @@ JS::ThrowCompletionOr<JS::NonnullGCPtr<JS::Object>> OptionConstructor::construct
     if (vm.argument_count() > 0) {
         auto text = TRY(vm.argument(0).to_deprecated_string(vm));
         if (!text.is_empty()) {
-            auto new_text_node = vm.heap().allocate<DOM::Text>(realm, document, text);
+            auto new_text_node = MUST_OR_THROW_OOM(vm.heap().allocate<DOM::Text>(realm, document, text));
             MUST(option_element->append_child(*new_text_node));
         }
     }

Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.cpp

@@ -14,7 +14,7 @@ namespace Web::CSS {
 
 CSSFontFaceRule* CSSFontFaceRule::create(JS::Realm& realm, FontFace&& font_face)
 {
-    return realm.heap().allocate<CSSFontFaceRule>(realm, realm, move(font_face));
+    return realm.heap().allocate<CSSFontFaceRule>(realm, realm, move(font_face)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CSSFontFaceRule::CSSFontFaceRule(JS::Realm& realm, FontFace&& font_face)

Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp

@@ -21,7 +21,7 @@ namespace Web::CSS {
 CSSImportRule* CSSImportRule::create(AK::URL url, DOM::Document& document)
 {
     auto& realm = document.realm();
-    return realm.heap().allocate<CSSImportRule>(realm, move(url), document);
+    return realm.heap().allocate<CSSImportRule>(realm, move(url), document).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CSSImportRule::CSSImportRule(AK::URL url, DOM::Document& document)

Userland/Libraries/LibWeb/CSS/CSSMediaRule.cpp

@@ -14,7 +14,7 @@ namespace Web::CSS {
 
 CSSMediaRule* CSSMediaRule::create(JS::Realm& realm, MediaList& media_queries, CSSRuleList& rules)
 {
-    return realm.heap().allocate<CSSMediaRule>(realm, realm, media_queries, rules);
+    return realm.heap().allocate<CSSMediaRule>(realm, realm, media_queries, rules).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CSSMediaRule::CSSMediaRule(JS::Realm& realm, MediaList& media, CSSRuleList& rules)

Userland/Libraries/LibWeb/CSS/CSSRuleList.cpp

@@ -19,7 +19,7 @@ namespace Web::CSS {
 
 CSSRuleList* CSSRuleList::create(JS::Realm& realm, JS::MarkedVector<CSSRule*> const& rules)
 {
-    auto rule_list = realm.heap().allocate<CSSRuleList>(realm, realm);
+    auto rule_list = realm.heap().allocate<CSSRuleList>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
     for (auto* rule : rules)
         rule_list->m_rules.append(*rule);
     return rule_list;
@@ -32,7 +32,7 @@ CSSRuleList::CSSRuleList(JS::Realm& realm)
 
 CSSRuleList* CSSRuleList::create_empty(JS::Realm& realm)
 {
-    return realm.heap().allocate<CSSRuleList>(realm, realm);
+    return realm.heap().allocate<CSSRuleList>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::ThrowCompletionOr<void> CSSRuleList::initialize(JS::Realm& realm)

Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp

@@ -21,7 +21,7 @@ CSSStyleDeclaration::CSSStyleDeclaration(JS::Realm& realm)
 
 PropertyOwningCSSStyleDeclaration* PropertyOwningCSSStyleDeclaration::create(JS::Realm& realm, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
 {
-    return realm.heap().allocate<PropertyOwningCSSStyleDeclaration>(realm, realm, move(properties), move(custom_properties));
+    return realm.heap().allocate<PropertyOwningCSSStyleDeclaration>(realm, realm, move(properties), move(custom_properties)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 PropertyOwningCSSStyleDeclaration::PropertyOwningCSSStyleDeclaration(JS::Realm& realm, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
@@ -41,7 +41,7 @@ DeprecatedString PropertyOwningCSSStyleDeclaration::item(size_t index) const
 ElementInlineCSSStyleDeclaration* ElementInlineCSSStyleDeclaration::create(DOM::Element& element, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
 {
     auto& realm = element.realm();
-    return realm.heap().allocate<ElementInlineCSSStyleDeclaration>(realm, element, move(properties), move(custom_properties));
+    return realm.heap().allocate<ElementInlineCSSStyleDeclaration>(realm, element, move(properties), move(custom_properties)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 ElementInlineCSSStyleDeclaration::ElementInlineCSSStyleDeclaration(DOM::Element& element, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)

Userland/Libraries/LibWeb/CSS/CSSStyleRule.cpp

@@ -13,7 +13,7 @@ namespace Web::CSS {
 
 CSSStyleRule* CSSStyleRule::create(JS::Realm& realm, NonnullRefPtrVector<Web::CSS::Selector>&& selectors, CSSStyleDeclaration& declaration)
 {
-    return realm.heap().allocate<CSSStyleRule>(realm, realm, move(selectors), declaration);
+    return realm.heap().allocate<CSSStyleRule>(realm, realm, move(selectors), declaration).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CSSStyleRule::CSSStyleRule(JS::Realm& realm, NonnullRefPtrVector<Selector>&& selectors, CSSStyleDeclaration& declaration)

Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp

@@ -16,7 +16,7 @@ namespace Web::CSS {
 
 CSSStyleSheet* CSSStyleSheet::create(JS::Realm& realm, CSSRuleList& rules, MediaList& media, Optional<AK::URL> location)
 {
-    return realm.heap().allocate<CSSStyleSheet>(realm, realm, rules, media, move(location));
+    return realm.heap().allocate<CSSStyleSheet>(realm, realm, rules, media, move(location)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CSSStyleSheet::CSSStyleSheet(JS::Realm& realm, CSSRuleList& rules, MediaList& media, Optional<AK::URL> location)

Userland/Libraries/LibWeb/CSS/CSSSupportsRule.cpp

@@ -13,7 +13,7 @@ namespace Web::CSS {
 
 CSSSupportsRule* CSSSupportsRule::create(JS::Realm& realm, NonnullRefPtr<Supports>&& supports, CSSRuleList& rules)
 {
-    return realm.heap().allocate<CSSSupportsRule>(realm, realm, move(supports), rules);
+    return realm.heap().allocate<CSSSupportsRule>(realm, realm, move(supports), rules).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CSSSupportsRule::CSSSupportsRule(JS::Realm& realm, NonnullRefPtr<Supports>&& supports, CSSRuleList& rules)

Userland/Libraries/LibWeb/CSS/MediaList.cpp

@@ -14,7 +14,7 @@ namespace Web::CSS {
 
 MediaList* MediaList::create(JS::Realm& realm, NonnullRefPtrVector<MediaQuery>&& media)
 {
-    return realm.heap().allocate<MediaList>(realm, realm, move(media));
+    return realm.heap().allocate<MediaList>(realm, realm, move(media)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 MediaList::MediaList(JS::Realm& realm, NonnullRefPtrVector<MediaQuery>&& media)

Userland/Libraries/LibWeb/CSS/MediaQueryList.cpp

@@ -17,7 +17,7 @@ namespace Web::CSS {
 
 JS::NonnullGCPtr<MediaQueryList> MediaQueryList::create(DOM::Document& document, NonnullRefPtrVector<MediaQuery>&& media)
 {
-    return document.heap().allocate<MediaQueryList>(document.realm(), document, move(media));
+    return document.heap().allocate<MediaQueryList>(document.realm(), document, move(media)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 MediaQueryList::MediaQueryList(DOM::Document& document, NonnullRefPtrVector<MediaQuery>&& media)

Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.cpp

@@ -12,7 +12,7 @@ namespace Web::CSS {
 
 MediaQueryListEvent* MediaQueryListEvent::construct_impl(JS::Realm& realm, DeprecatedFlyString const& event_name, MediaQueryListEventInit const& event_init)
 {
-    return realm.heap().allocate<MediaQueryListEvent>(realm, realm, event_name, event_init);
+    return realm.heap().allocate<MediaQueryListEvent>(realm, realm, event_name, event_init).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 MediaQueryListEvent::MediaQueryListEvent(JS::Realm& realm, DeprecatedFlyString const& event_name, MediaQueryListEventInit const& event_init)

Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp

@@ -22,7 +22,7 @@ namespace Web::CSS {
 
 ResolvedCSSStyleDeclaration* ResolvedCSSStyleDeclaration::create(DOM::Element& element)
 {
-    return element.realm().heap().allocate<ResolvedCSSStyleDeclaration>(element.realm(), element);
+    return element.realm().heap().allocate<ResolvedCSSStyleDeclaration>(element.realm(), element).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 ResolvedCSSStyleDeclaration::ResolvedCSSStyleDeclaration(DOM::Element& element)

Userland/Libraries/LibWeb/CSS/Screen.cpp

@@ -15,7 +15,7 @@ namespace Web::CSS {
 
 JS::NonnullGCPtr<Screen> Screen::create(HTML::Window& window)
 {
-    return window.heap().allocate<Screen>(window.realm(), window);
+    return window.heap().allocate<Screen>(window.realm(), window).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Screen::Screen(HTML::Window& window)

Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp

@@ -48,7 +48,7 @@ void StyleSheetList::remove_sheet(CSSStyleSheet& sheet)
 StyleSheetList* StyleSheetList::create(DOM::Document& document)
 {
     auto& realm = document.realm();
-    return realm.heap().allocate<StyleSheetList>(realm, document);
+    return realm.heap().allocate<StyleSheetList>(realm, document).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 StyleSheetList::StyleSheetList(DOM::Document& document)

Userland/Libraries/LibWeb/Crypto/Crypto.cpp

@@ -16,7 +16,7 @@ namespace Web::Crypto {
 
 JS::NonnullGCPtr<Crypto> Crypto::create(JS::Realm& realm)
 {
-    return realm.heap().allocate<Crypto>(realm, realm);
+    return realm.heap().allocate<Crypto>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Crypto::Crypto(JS::Realm& realm)

Userland/Libraries/LibWeb/Crypto/SubtleCrypto.cpp

@@ -16,7 +16,7 @@ namespace Web::Crypto {
 
 JS::NonnullGCPtr<SubtleCrypto> SubtleCrypto::create(JS::Realm& realm)
 {
-    return realm.heap().allocate<SubtleCrypto>(realm, realm);
+    return realm.heap().allocate<SubtleCrypto>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 SubtleCrypto::SubtleCrypto(JS::Realm& realm)

Userland/Libraries/LibWeb/DOM/AbortController.cpp

@@ -13,7 +13,7 @@ namespace Web::DOM {
 JS::NonnullGCPtr<AbortController> AbortController::construct_impl(JS::Realm& realm)
 {
     auto signal = AbortSignal::construct_impl(realm);
-    return realm.heap().allocate<AbortController>(realm, realm, move(signal));
+    return realm.heap().allocate<AbortController>(realm, realm, move(signal)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 // https://dom.spec.whatwg.org/#dom-abortcontroller-abortcontroller

Userland/Libraries/LibWeb/DOM/AbortSignal.cpp

@@ -14,7 +14,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<AbortSignal> AbortSignal::construct_impl(JS::Realm& realm)
 {
-    return realm.heap().allocate<AbortSignal>(realm, realm);
+    return realm.heap().allocate<AbortSignal>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 AbortSignal::AbortSignal(JS::Realm& realm)

Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.cpp

@@ -15,7 +15,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<AccessibilityTreeNode> AccessibilityTreeNode::create(Document* document, DOM::Node const* value)
 {
-    return *document->heap().allocate<AccessibilityTreeNode>(document->realm(), value);
+    return *document->heap().allocate<AccessibilityTreeNode>(document->realm(), value).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 AccessibilityTreeNode::AccessibilityTreeNode(JS::GCPtr<DOM::Node> value)

Userland/Libraries/LibWeb/DOM/Attr.cpp

@@ -15,12 +15,12 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<Attr> Attr::create(Document& document, DeprecatedFlyString local_name, DeprecatedString value, Element const* owner_element)
 {
-    return document.heap().allocate<Attr>(document.realm(), document, QualifiedName(move(local_name), {}, {}), move(value), owner_element);
+    return document.heap().allocate<Attr>(document.realm(), document, QualifiedName(move(local_name), {}, {}), move(value), owner_element).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Attr> Attr::clone(Document& document)
 {
-    return *heap().allocate<Attr>(realm(), document, m_qualified_name, m_value, nullptr);
+    return *heap().allocate<Attr>(realm(), document, m_qualified_name, m_value, nullptr).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Attr::Attr(Document& document, QualifiedName qualified_name, DeprecatedString value, Element const* owner_element)

Userland/Libraries/LibWeb/DOM/Comment.cpp

@@ -19,7 +19,7 @@ Comment::Comment(Document& document, DeprecatedString const& data)
 JS::NonnullGCPtr<Comment> Comment::construct_impl(JS::Realm& realm, DeprecatedString const& data)
 {
     auto& window = verify_cast<HTML::Window>(realm.global_object());
-    return realm.heap().allocate<Comment>(realm, window.associated_document(), data);
+    return realm.heap().allocate<Comment>(realm, window.associated_document(), data).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 }

Userland/Libraries/LibWeb/DOM/CustomEvent.cpp

@@ -13,7 +13,7 @@ namespace Web::DOM {
 
 CustomEvent* CustomEvent::create(JS::Realm& realm, DeprecatedFlyString const& event_name, CustomEventInit const& event_init)
 {
-    return realm.heap().allocate<CustomEvent>(realm, realm, event_name, event_init);
+    return realm.heap().allocate<CustomEvent>(realm, realm, event_name, event_init).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 CustomEvent* CustomEvent::construct_impl(JS::Realm& realm, DeprecatedFlyString const& event_name, CustomEventInit const& event_init)

Userland/Libraries/LibWeb/DOM/DOMImplementation.cpp

@@ -20,7 +20,7 @@ namespace Web::DOM {
 JS::NonnullGCPtr<DOMImplementation> DOMImplementation::create(Document& document)
 {
     auto& realm = document.realm();
-    return realm.heap().allocate<DOMImplementation>(realm, document);
+    return realm.heap().allocate<DOMImplementation>(realm, document).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 DOMImplementation::DOMImplementation(Document& document)
@@ -84,7 +84,7 @@ JS::NonnullGCPtr<Document> DOMImplementation::create_html_document(DeprecatedStr
     html_document->set_content_type("text/html");
     html_document->set_ready_for_post_load_tasks(true);
 
-    auto doctype = heap().allocate<DocumentType>(realm(), html_document);
+    auto doctype = heap().allocate<DocumentType>(realm(), html_document).release_allocated_value_but_fixme_should_propagate_errors();
     doctype->set_name("html");
     MUST(html_document->append_child(*doctype));
 
@@ -98,7 +98,7 @@ JS::NonnullGCPtr<Document> DOMImplementation::create_html_document(DeprecatedStr
         auto title_element = create_element(html_document, HTML::TagNames::title, Namespace::HTML);
         MUST(head_element->append_child(title_element));
 
-        auto text_node = heap().allocate<Text>(realm(), html_document, title);
+        auto text_node = heap().allocate<Text>(realm(), html_document, title).release_allocated_value_but_fixme_should_propagate_errors();
         MUST(title_element->append_child(*text_node));
     }
 

Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp

@@ -55,7 +55,7 @@ namespace Web::DOM {
 DOMTokenList* DOMTokenList::create(Element const& associated_element, DeprecatedFlyString associated_attribute)
 {
     auto& realm = associated_element.realm();
-    return realm.heap().allocate<DOMTokenList>(realm, associated_element, move(associated_attribute));
+    return realm.heap().allocate<DOMTokenList>(realm, associated_element, move(associated_attribute)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 // https://dom.spec.whatwg.org/#ref-for-domtokenlist%E2%91%A0%E2%91%A2

Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -290,7 +290,7 @@ JS::NonnullGCPtr<Document> Document::construct_impl(JS::Realm& realm)
 
 JS::NonnullGCPtr<Document> Document::create(JS::Realm& realm, AK::URL const& url)
 {
-    return realm.heap().allocate<Document>(realm, realm, url);
+    return realm.heap().allocate<Document>(realm, realm, url).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 Document::Document(JS::Realm& realm, const AK::URL& url)
@@ -687,7 +687,7 @@ void Document::set_title(DeprecatedString const& title)
     }
 
     title_element->remove_all_children(true);
-    MUST(title_element->append_child(heap().allocate<Text>(realm(), *this, title)));
+    MUST(title_element->append_child(heap().allocate<Text>(realm(), *this, title).release_allocated_value_but_fixme_should_propagate_errors()));
 
     if (auto* page = this->page()) {
         if (browsing_context() == &page->top_level_browsing_context())
@@ -1230,17 +1230,17 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> Document::create_element_ns(Depre
 
 JS::NonnullGCPtr<DocumentFragment> Document::create_document_fragment()
 {
-    return heap().allocate<DocumentFragment>(realm(), *this);
+    return heap().allocate<DocumentFragment>(realm(), *this).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Text> Document::create_text_node(DeprecatedString const& data)
 {
-    return heap().allocate<Text>(realm(), *this, data);
+    return heap().allocate<Text>(realm(), *this, data).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Comment> Document::create_comment(DeprecatedString const& data)
 {
-    return heap().allocate<Comment>(realm(), *this, data);
+    return heap().allocate<Comment>(realm(), *this, data).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 // https://dom.spec.whatwg.org/#dom-document-createprocessinginstruction
@@ -1251,7 +1251,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ProcessingInstruction>> Document::create_pr
     // FIXME: 2. If data contains the string "?>", then throw an "InvalidCharacterError" DOMException.
 
     // 3. Return a new ProcessingInstruction node, with target set to target, data set to data, and node document set to this.
-    return JS::NonnullGCPtr { *heap().allocate<ProcessingInstruction>(realm(), *this, data, target) };
+    return MUST_OR_THROW_OOM(heap().allocate<ProcessingInstruction>(realm(), *this, data, target));
 }
 
 JS::NonnullGCPtr<Range> Document::create_range()

Userland/Libraries/LibWeb/DOM/DocumentFragment.cpp

@@ -37,7 +37,7 @@ void DocumentFragment::set_host(Web::DOM::Element* element)
 JS::NonnullGCPtr<DocumentFragment> DocumentFragment::construct_impl(JS::Realm& realm)
 {
     auto& window = verify_cast<HTML::Window>(realm.global_object());
-    return realm.heap().allocate<DocumentFragment>(realm, window.associated_document());
+    return realm.heap().allocate<DocumentFragment>(realm, window.associated_document()).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 }

Userland/Libraries/LibWeb/DOM/DocumentType.cpp

@@ -11,7 +11,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<DocumentType> DocumentType::create(Document& document)
 {
-    return document.heap().allocate<DocumentType>(document.realm(), document);
+    return document.heap().allocate<DocumentType>(document.realm(), document).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 DocumentType::DocumentType(Document& document)

Userland/Libraries/LibWeb/DOM/Element.cpp

@@ -1180,7 +1180,7 @@ WebIDL::ExceptionOr<JS::GCPtr<Element>> Element::insert_adjacent_element(Depreca
 WebIDL::ExceptionOr<void> Element::insert_adjacent_text(DeprecatedString const& where, DeprecatedString const& data)
 {
     // 1. Let text be a new Text node whose data is data and node document is this’s node document.
-    auto text = heap().allocate<DOM::Text>(realm(), document(), data);
+    auto text = MUST_OR_THROW_OOM(heap().allocate<DOM::Text>(realm(), document(), data));
 
     // 2. Run insert adjacent, given this, where, and text.
     // Spec Note: This method returns nothing because it existed before we had a chance to design it.

Userland/Libraries/LibWeb/DOM/ElementFactory.cpp

@@ -120,180 +120,180 @@ JS::NonnullGCPtr<Element> create_element(Document& document, DeprecatedFlyString
 
     auto qualified_name = QualifiedName { local_name, prefix, namespace_ };
     if (lowercase_tag_name == HTML::TagNames::a)
-        return realm.heap().allocate<HTML::HTMLAnchorElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLAnchorElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::area)
-        return realm.heap().allocate<HTML::HTMLAreaElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLAreaElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::audio)
-        return realm.heap().allocate<HTML::HTMLAudioElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLAudioElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::base)
-        return realm.heap().allocate<HTML::HTMLBaseElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLBaseElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::blink)
-        return realm.heap().allocate<HTML::HTMLBlinkElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLBlinkElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::body)
-        return realm.heap().allocate<HTML::HTMLBodyElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLBodyElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::br)
-        return realm.heap().allocate<HTML::HTMLBRElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLBRElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::button)
-        return realm.heap().allocate<HTML::HTMLButtonElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLButtonElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::canvas)
-        return realm.heap().allocate<HTML::HTMLCanvasElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLCanvasElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::data)
-        return realm.heap().allocate<HTML::HTMLDataElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLDataElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::datalist)
-        return realm.heap().allocate<HTML::HTMLDataListElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLDataListElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::details)
-        return realm.heap().allocate<HTML::HTMLDetailsElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLDetailsElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::dialog)
-        return realm.heap().allocate<HTML::HTMLDialogElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLDialogElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::dir)
-        return realm.heap().allocate<HTML::HTMLDirectoryElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLDirectoryElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::div)
-        return realm.heap().allocate<HTML::HTMLDivElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLDivElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::dl)
-        return realm.heap().allocate<HTML::HTMLDListElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLDListElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::embed)
-        return realm.heap().allocate<HTML::HTMLEmbedElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLEmbedElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::fieldset)
-        return realm.heap().allocate<HTML::HTMLFieldSetElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLFieldSetElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::font)
-        return realm.heap().allocate<HTML::HTMLFontElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLFontElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::form)
-        return realm.heap().allocate<HTML::HTMLFormElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLFormElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::frame)
-        return realm.heap().allocate<HTML::HTMLFrameElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLFrameElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::frameset)
-        return realm.heap().allocate<HTML::HTMLFrameSetElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLFrameSetElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::head)
-        return realm.heap().allocate<HTML::HTMLHeadElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLHeadElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.is_one_of(HTML::TagNames::h1, HTML::TagNames::h2, HTML::TagNames::h3, HTML::TagNames::h4, HTML::TagNames::h5, HTML::TagNames::h6))
-        return realm.heap().allocate<HTML::HTMLHeadingElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLHeadingElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::hr)
-        return realm.heap().allocate<HTML::HTMLHRElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLHRElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::html)
-        return realm.heap().allocate<HTML::HTMLHtmlElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLHtmlElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::iframe)
-        return realm.heap().allocate<HTML::HTMLIFrameElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLIFrameElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::img)
-        return realm.heap().allocate<HTML::HTMLImageElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLImageElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::input)
-        return realm.heap().allocate<HTML::HTMLInputElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLInputElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::label)
-        return realm.heap().allocate<HTML::HTMLLabelElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLLabelElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::legend)
-        return realm.heap().allocate<HTML::HTMLLegendElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLLegendElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::li)
-        return realm.heap().allocate<HTML::HTMLLIElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLLIElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::link)
-        return realm.heap().allocate<HTML::HTMLLinkElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLLinkElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::map)
-        return realm.heap().allocate<HTML::HTMLMapElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLMapElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::marquee)
-        return realm.heap().allocate<HTML::HTMLMarqueeElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLMarqueeElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::menu)
-        return realm.heap().allocate<HTML::HTMLMenuElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLMenuElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::meta)
-        return realm.heap().allocate<HTML::HTMLMetaElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLMetaElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::meter)
-        return realm.heap().allocate<HTML::HTMLMeterElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLMeterElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.is_one_of(HTML::TagNames::ins, HTML::TagNames::del))
-        return realm.heap().allocate<HTML::HTMLModElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLModElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::object)
-        return realm.heap().allocate<HTML::HTMLObjectElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLObjectElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::ol)
-        return realm.heap().allocate<HTML::HTMLOListElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLOListElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::optgroup)
-        return realm.heap().allocate<HTML::HTMLOptGroupElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLOptGroupElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::option)
-        return realm.heap().allocate<HTML::HTMLOptionElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLOptionElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::output)
-        return realm.heap().allocate<HTML::HTMLOutputElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLOutputElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::p)
-        return realm.heap().allocate<HTML::HTMLParagraphElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLParagraphElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::param)
-        return realm.heap().allocate<HTML::HTMLParamElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLParamElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::picture)
-        return realm.heap().allocate<HTML::HTMLPictureElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLPictureElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     // NOTE: The obsolete elements "listing" and "xmp" are explicitly mapped to HTMLPreElement in the specification.
     if (lowercase_tag_name.is_one_of(HTML::TagNames::pre, HTML::TagNames::listing, HTML::TagNames::xmp))
-        return realm.heap().allocate<HTML::HTMLPreElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLPreElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::progress)
-        return realm.heap().allocate<HTML::HTMLProgressElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLProgressElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.is_one_of(HTML::TagNames::blockquote, HTML::TagNames::q))
-        return realm.heap().allocate<HTML::HTMLQuoteElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLQuoteElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::script)
-        return realm.heap().allocate<HTML::HTMLScriptElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLScriptElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::select)
-        return realm.heap().allocate<HTML::HTMLSelectElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLSelectElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::slot)
-        return realm.heap().allocate<HTML::HTMLSlotElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLSlotElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::source)
-        return realm.heap().allocate<HTML::HTMLSourceElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLSourceElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::span)
-        return realm.heap().allocate<HTML::HTMLSpanElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLSpanElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::style)
-        return realm.heap().allocate<HTML::HTMLStyleElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLStyleElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::caption)
-        return realm.heap().allocate<HTML::HTMLTableCaptionElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTableCaptionElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.is_one_of(Web::HTML::TagNames::td, Web::HTML::TagNames::th))
-        return realm.heap().allocate<HTML::HTMLTableCellElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTableCellElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.is_one_of(HTML::TagNames::colgroup, HTML::TagNames::col))
-        return realm.heap().allocate<HTML::HTMLTableColElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTableColElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::table)
-        return realm.heap().allocate<HTML::HTMLTableElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTableElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::tr)
-        return realm.heap().allocate<HTML::HTMLTableRowElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTableRowElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.is_one_of(HTML::TagNames::tbody, HTML::TagNames::thead, HTML::TagNames::tfoot))
-        return realm.heap().allocate<HTML::HTMLTableSectionElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTableSectionElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::template_)
-        return realm.heap().allocate<HTML::HTMLTemplateElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTemplateElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::textarea)
-        return realm.heap().allocate<HTML::HTMLTextAreaElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTextAreaElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::time)
-        return realm.heap().allocate<HTML::HTMLTimeElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTimeElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::title)
-        return realm.heap().allocate<HTML::HTMLTitleElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTitleElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::track)
-        return realm.heap().allocate<HTML::HTMLTrackElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLTrackElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::ul)
-        return realm.heap().allocate<HTML::HTMLUListElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLUListElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == HTML::TagNames::video)
-        return realm.heap().allocate<HTML::HTMLVideoElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLVideoElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.is_one_of(
             HTML::TagNames::article, HTML::TagNames::section, HTML::TagNames::nav, HTML::TagNames::aside, HTML::TagNames::hgroup, HTML::TagNames::header, HTML::TagNames::footer, HTML::TagNames::address, HTML::TagNames::dt, HTML::TagNames::dd, HTML::TagNames::figure, HTML::TagNames::figcaption, HTML::TagNames::main, HTML::TagNames::em, HTML::TagNames::strong, HTML::TagNames::small, HTML::TagNames::s, HTML::TagNames::cite, HTML::TagNames::dfn, HTML::TagNames::abbr, HTML::TagNames::ruby, HTML::TagNames::rt, HTML::TagNames::rp, HTML::TagNames::code, HTML::TagNames::var, HTML::TagNames::samp, HTML::TagNames::kbd, HTML::TagNames::sub, HTML::TagNames::sup, HTML::TagNames::i, HTML::TagNames::b, HTML::TagNames::u, HTML::TagNames::mark, HTML::TagNames::bdi, HTML::TagNames::bdo, HTML::TagNames::wbr, HTML::TagNames::summary, HTML::TagNames::noscript,
             // Obsolete
             HTML::TagNames::acronym, HTML::TagNames::basefont, HTML::TagNames::big, HTML::TagNames::center, HTML::TagNames::nobr, HTML::TagNames::noembed, HTML::TagNames::noframes, HTML::TagNames::plaintext, HTML::TagNames::rb, HTML::TagNames::rtc, HTML::TagNames::strike, HTML::TagNames::tt))
-        return realm.heap().allocate<HTML::HTMLElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<HTML::HTMLElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::svg)
-        return realm.heap().allocate<SVG::SVGSVGElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGSVGElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     // FIXME: Support SVG's mixedCase tag names properly.
     if (lowercase_tag_name.equals_ignoring_case(SVG::TagNames::clipPath))
-        return realm.heap().allocate<SVG::SVGClipPathElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGClipPathElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::circle)
-        return realm.heap().allocate<SVG::SVGCircleElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGCircleElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.equals_ignoring_case(SVG::TagNames::defs))
-        return realm.heap().allocate<SVG::SVGDefsElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGDefsElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::ellipse)
-        return realm.heap().allocate<SVG::SVGEllipseElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGEllipseElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name.equals_ignoring_case(SVG::TagNames::foreignObject))
-        return realm.heap().allocate<SVG::SVGForeignObjectElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGForeignObjectElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::line)
-        return realm.heap().allocate<SVG::SVGLineElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGLineElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::path)
-        return realm.heap().allocate<SVG::SVGPathElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGPathElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::polygon)
-        return realm.heap().allocate<SVG::SVGPolygonElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGPolygonElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::polyline)
-        return realm.heap().allocate<SVG::SVGPolylineElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGPolylineElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::rect)
-        return realm.heap().allocate<SVG::SVGRectElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGRectElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::g)
-        return realm.heap().allocate<SVG::SVGGElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGGElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
     if (lowercase_tag_name == SVG::TagNames::text)
-        return realm.heap().allocate<SVG::SVGTextContentElement>(realm, document, move(qualified_name));
+        return realm.heap().allocate<SVG::SVGTextContentElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
 
     // FIXME: If name is a valid custom element name, then return HTMLElement.
 
-    return realm.heap().allocate<HTML::HTMLUnknownElement>(realm, document, move(qualified_name));
+    return realm.heap().allocate<HTML::HTMLUnknownElement>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 }

Userland/Libraries/LibWeb/DOM/Event.cpp

@@ -16,7 +16,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<Event> Event::create(JS::Realm& realm, DeprecatedFlyString const& event_name, EventInit const& event_init)
 {
-    return realm.heap().allocate<Event>(realm, realm, event_name, event_init);
+    return realm.heap().allocate<Event>(realm, realm, event_name, event_init).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Event> Event::construct_impl(JS::Realm& realm, DeprecatedFlyString const& event_name, EventInit const& event_init)

Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp

@@ -15,7 +15,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<HTMLCollection> HTMLCollection::create(ParentNode& root, Function<bool(Element const&)> filter)
 {
-    return root.heap().allocate<HTMLCollection>(root.realm(), root, move(filter));
+    return root.heap().allocate<HTMLCollection>(root.realm(), root, move(filter)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 HTMLCollection::HTMLCollection(ParentNode& root, Function<bool(Element const&)> filter)

Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp

@@ -10,7 +10,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<IDLEventListener> IDLEventListener::create(JS::Realm& realm, JS::NonnullGCPtr<WebIDL::CallbackType> callback)
 {
-    return realm.heap().allocate<IDLEventListener>(realm, realm, move(callback));
+    return realm.heap().allocate<IDLEventListener>(realm, realm, move(callback)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 IDLEventListener::IDLEventListener(JS::Realm& realm, JS::NonnullGCPtr<WebIDL::CallbackType> callback)

Userland/Libraries/LibWeb/DOM/LiveNodeList.cpp

@@ -12,7 +12,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<NodeList> LiveNodeList::create(JS::Realm& realm, Node& root, Function<bool(Node const&)> filter)
 {
-    return realm.heap().allocate<LiveNodeList>(realm, realm, root, move(filter));
+    return realm.heap().allocate<LiveNodeList>(realm, realm, root, move(filter)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 LiveNodeList::LiveNodeList(JS::Realm& realm, Node& root, Function<bool(Node const&)> filter)

Userland/Libraries/LibWeb/DOM/MutationObserver.cpp

@@ -13,7 +13,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<MutationObserver> MutationObserver::construct_impl(JS::Realm& realm, JS::GCPtr<WebIDL::CallbackType> callback)
 {
-    return realm.heap().allocate<MutationObserver>(realm, realm, callback);
+    return realm.heap().allocate<MutationObserver>(realm, realm, callback).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 // https://dom.spec.whatwg.org/#dom-mutationobserver-mutationobserver

Userland/Libraries/LibWeb/DOM/MutationRecord.cpp

@@ -14,7 +14,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<MutationRecord> MutationRecord::create(JS::Realm& realm, DeprecatedFlyString const& type, Node& target, NodeList& added_nodes, NodeList& removed_nodes, Node* previous_sibling, Node* next_sibling, DeprecatedString const& attribute_name, DeprecatedString const& attribute_namespace, DeprecatedString const& old_value)
 {
-    return realm.heap().allocate<MutationRecord>(realm, realm, type, target, added_nodes, removed_nodes, previous_sibling, next_sibling, attribute_name, attribute_namespace, old_value);
+    return realm.heap().allocate<MutationRecord>(realm, realm, type, target, added_nodes, removed_nodes, previous_sibling, next_sibling, attribute_name, attribute_namespace, old_value).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 MutationRecord::MutationRecord(JS::Realm& realm, DeprecatedFlyString const& type, Node& target, NodeList& added_nodes, NodeList& removed_nodes, Node* previous_sibling, Node* next_sibling, DeprecatedString const& attribute_name, DeprecatedString const& attribute_namespace, DeprecatedString const& old_value)

Userland/Libraries/LibWeb/DOM/NamedNodeMap.cpp

@@ -16,7 +16,7 @@ namespace Web::DOM {
 JS::NonnullGCPtr<NamedNodeMap> NamedNodeMap::create(Element& element)
 {
     auto& realm = element.realm();
-    return realm.heap().allocate<NamedNodeMap>(realm, element);
+    return realm.heap().allocate<NamedNodeMap>(realm, element).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NamedNodeMap::NamedNodeMap(Element& element)

Userland/Libraries/LibWeb/DOM/Node.cpp

@@ -743,7 +743,7 @@ JS::NonnullGCPtr<Node> Node::clone_node(Document* document, bool clone_children)
     } else if (is<DocumentType>(this)) {
         // DocumentType
         auto document_type = verify_cast<DocumentType>(this);
-        auto document_type_copy = heap().allocate<DocumentType>(realm(), *document);
+        auto document_type_copy = heap().allocate<DocumentType>(realm(), *document).release_allocated_value_but_fixme_should_propagate_errors();
 
         // Set copy’s name, public ID, and system ID to those of node.
         document_type_copy->set_name(document_type->name());
@@ -760,26 +760,26 @@ JS::NonnullGCPtr<Node> Node::clone_node(Document* document, bool clone_children)
         auto text = verify_cast<Text>(this);
 
         // Set copy’s data to that of node.
-        auto text_copy = heap().allocate<Text>(realm(), *document, text->data());
+        auto text_copy = heap().allocate<Text>(realm(), *document, text->data()).release_allocated_value_but_fixme_should_propagate_errors();
         copy = move(text_copy);
     } else if (is<Comment>(this)) {
         // Comment
         auto comment = verify_cast<Comment>(this);
 
         // Set copy’s data to that of node.
-        auto comment_copy = heap().allocate<Comment>(realm(), *document, comment->data());
+        auto comment_copy = heap().allocate<Comment>(realm(), *document, comment->data()).release_allocated_value_but_fixme_should_propagate_errors();
         copy = move(comment_copy);
     } else if (is<ProcessingInstruction>(this)) {
         // ProcessingInstruction
         auto processing_instruction = verify_cast<ProcessingInstruction>(this);
 
         // Set copy’s target and data to those of node.
-        auto processing_instruction_copy = heap().allocate<ProcessingInstruction>(realm(), *document, processing_instruction->data(), processing_instruction->target());
+        auto processing_instruction_copy = heap().allocate<ProcessingInstruction>(realm(), *document, processing_instruction->data(), processing_instruction->target()).release_allocated_value_but_fixme_should_propagate_errors();
         copy = processing_instruction_copy;
     }
     // Otherwise, Do nothing.
     else if (is<DocumentFragment>(this)) {
-        copy = heap().allocate<DocumentFragment>(realm(), *document);
+        copy = heap().allocate<DocumentFragment>(realm(), *document).release_allocated_value_but_fixme_should_propagate_errors();
     }
 
     // FIXME: 4. Set copy’s node document and document to copy, if copy is a document, and set copy’s node document to document otherwise.
@@ -1179,7 +1179,7 @@ void Node::string_replace_all(DeprecatedString const& string)
 
     // 2. If string is not the empty string, then set node to a new Text node whose data is string and node document is parent’s node document.
     if (!string.is_empty())
-        node = heap().allocate<Text>(realm(), document(), string);
+        node = heap().allocate<Text>(realm(), document(), string).release_allocated_value_but_fixme_should_propagate_errors();
 
     // 3. Replace all with node within parent.
     replace_all(node);

Userland/Libraries/LibWeb/DOM/NodeFilter.cpp

@@ -11,7 +11,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<NodeFilter> NodeFilter::create(JS::Realm& realm, WebIDL::CallbackType& callback)
 {
-    return realm.heap().allocate<NodeFilter>(realm, realm, callback);
+    return realm.heap().allocate<NodeFilter>(realm, realm, callback).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 NodeFilter::NodeFilter(JS::Realm& realm, WebIDL::CallbackType& callback)

Userland/Libraries/LibWeb/DOM/NodeIterator.cpp

@@ -53,7 +53,7 @@ JS::NonnullGCPtr<NodeIterator> NodeIterator::create(Node& root, unsigned what_to
     // 2. Set iterator’s root and iterator’s reference to root.
     // 3. Set iterator’s pointer before reference to true.
     auto& realm = root.realm();
-    auto iterator = realm.heap().allocate<NodeIterator>(realm, root);
+    auto iterator = realm.heap().allocate<NodeIterator>(realm, root).release_allocated_value_but_fixme_should_propagate_errors();
 
     // 4. Set iterator’s whatToShow to whatToShow.
     iterator->m_what_to_show = what_to_show;

Userland/Libraries/LibWeb/DOM/NodeOperations.cpp

@@ -22,19 +22,19 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Node>> convert_nodes_to_single_node(Vector<
     // 4. Otherwise, set node to a new DocumentFragment node whose node document is document, and then append each node in nodes, if any, to it.
     // 5. Return node.
 
-    auto potentially_convert_string_to_text_node = [&document](Variant<JS::Handle<Node>, DeprecatedString> const& node) -> JS::NonnullGCPtr<Node> {
+    auto potentially_convert_string_to_text_node = [&document](Variant<JS::Handle<Node>, DeprecatedString> const& node) -> JS::ThrowCompletionOr<JS::NonnullGCPtr<Node>> {
         if (node.has<JS::Handle<Node>>())
             return *node.get<JS::Handle<Node>>();
 
-        return document.heap().allocate<DOM::Text>(document.realm(), document, node.get<DeprecatedString>());
+        return MUST_OR_THROW_OOM(document.heap().allocate<DOM::Text>(document.realm(), document, node.get<DeprecatedString>()));
     };
 
     if (nodes.size() == 1)
-        return potentially_convert_string_to_text_node(nodes.first());
+        return TRY(potentially_convert_string_to_text_node(nodes.first()));
 
-    auto document_fragment = document.heap().allocate<DOM::DocumentFragment>(document.realm(), document);
+    auto document_fragment = MUST_OR_THROW_OOM(document.heap().allocate<DOM::DocumentFragment>(document.realm(), document));
     for (auto& unconverted_node : nodes) {
-        auto node = potentially_convert_string_to_text_node(unconverted_node);
+        auto node = TRY(potentially_convert_string_to_text_node(unconverted_node));
         (void)TRY(document_fragment->append_child(node));
     }
 

Userland/Libraries/LibWeb/DOM/Range.cpp

@@ -35,13 +35,13 @@ JS::NonnullGCPtr<Range> Range::create(HTML::Window& window)
 JS::NonnullGCPtr<Range> Range::create(Document& document)
 {
     auto& realm = document.realm();
-    return realm.heap().allocate<Range>(realm, document);
+    return realm.heap().allocate<Range>(realm, document).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Range> Range::create(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset)
 {
     auto& realm = start_container.realm();
-    return realm.heap().allocate<Range>(realm, start_container, start_offset, end_container, end_offset);
+    return realm.heap().allocate<Range>(realm, start_container, start_offset, end_container, end_offset).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Range> Range::construct_impl(JS::Realm& realm)
@@ -428,12 +428,12 @@ WebIDL::ExceptionOr<void> Range::select_node_contents(Node const& node)
 
 JS::NonnullGCPtr<Range> Range::clone_range() const
 {
-    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_start_container), m_start_offset, const_cast<Node&>(*m_end_container), m_end_offset);
+    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_start_container), m_start_offset, const_cast<Node&>(*m_end_container), m_end_offset).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Range> Range::inverted() const
 {
-    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_end_container), m_end_offset, const_cast<Node&>(*m_start_container), m_start_offset);
+    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_end_container), m_end_offset, const_cast<Node&>(*m_start_container), m_start_offset).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 JS::NonnullGCPtr<Range> Range::normalized() const
@@ -587,7 +587,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::extract_contents(
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::extract()
 {
     // 1. Let fragment be a new DocumentFragment node whose node document is range’s start node’s node document.
-    auto fragment = heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document()));
+    auto fragment = MUST_OR_THROW_OOM(heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document())));
 
     // 2. If range is collapsed, then return fragment.
     if (collapsed())
@@ -916,7 +916,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::clone_contents()
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::clone_the_contents()
 {
     // 1. Let fragment be a new DocumentFragment node whose node document is range’s start node’s node document.
-    auto fragment = heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document()));
+    auto fragment = MUST_OR_THROW_OOM(heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document())));
 
     // 2. If range is collapsed, then return fragment.
     if (collapsed())

Userland/Libraries/LibWeb/DOM/StaticNodeList.cpp

@@ -11,7 +11,7 @@ namespace Web::DOM {
 
 JS::NonnullGCPtr<NodeList> StaticNodeList::create(JS::Realm& realm, Vector<JS::Handle<Node>> static_nodes)
 {
-    return realm.heap().allocate<StaticNodeList>(realm, realm, move(static_nodes));
+    return realm.heap().allocate<StaticNodeList>(realm, realm, move(static_nodes)).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 StaticNodeList::StaticNodeList(JS::Realm& realm, Vector<JS::Handle<Node>> static_nodes)

Userland/Libraries/LibWeb/DOM/StaticRange.cpp

@@ -32,7 +32,7 @@ WebIDL::ExceptionOr<StaticRange*> StaticRange::construct_impl(JS::Realm& realm,
         return WebIDL::InvalidNodeTypeError::create(realm, "endContainer cannot be a DocumentType or Attribute node.");
 
     // 2. Set this’s start to (init["startContainer"], init["startOffset"]) and end to (init["endContainer"], init["endOffset"]).
-    return realm.heap().allocate<StaticRange>(realm, *init.start_container, init.start_offset, *init.end_container, init.end_offset).ptr();
+    return realm.heap().allocate<StaticRange>(realm, *init.start_container, init.start_offset, *init.end_container, init.end_offset).release_allocated_value_but_fixme_should_propagate_errors().ptr();
 }
 
 JS::ThrowCompletionOr<void> StaticRange::initialize(JS::Realm& realm)

Userland/Libraries/LibWeb/DOM/Text.cpp

@@ -43,7 +43,7 @@ JS::NonnullGCPtr<Text> Text::construct_impl(JS::Realm& realm, DeprecatedString c
 {
     // The new Text(data) constructor steps are to set this’s data to data and this’s node document to current global object’s associated Document.
     auto& window = verify_cast<HTML::Window>(HTML::current_global_object());
-    return realm.heap().allocate<Text>(realm, window.associated_document(), data);
+    return realm.heap().allocate<Text>(realm, window.associated_document(), data).release_allocated_value_but_fixme_should_propagate_errors();
 }
 
 void Text::set_owner_input_element(Badge<HTML::HTMLInputElement>, HTML::HTMLInputElement& input_element)
@@ -69,7 +69,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Text>> Text::split_text(size_t offset)
     auto new_data = TRY(substring_data(offset, count));
 
     // 5. Let new node be a new Text node, with the same node document as node. Set new node’s data to new data.
-    auto new_node = heap().allocate<Text>(realm(), document(), new_data);
+    auto new_node = MUST_OR_THROW_OOM(heap().allocate<Text>(realm(), document(), new_data));
 
     // 6. Let parent be node’s parent.
     JS::GCPtr<Node> parent = this->parent();

Userland/Libraries/LibWeb/DOM/TreeWalker.cpp

@@ -44,7 +44,7 @@ JS::NonnullGCPtr<TreeWalker> TreeWalker::create(Node& root, unsigned what_to_sho
     // 1. Let walker be a new TreeWalker object.
     // 2. Set walker’s root and walker’s current to root.
     auto& realm = root.realm();
-    auto walker = realm.heap().allocate<TreeWalker>(realm, root);
+    auto walker = realm.heap().allocate<TreeWalker>(realm, root).release_allocated_value_but_fixme_should_propagate_errors();
 
     // 3. Set walker’s whatToShow to whatToShow.
     walker->m_what_to_show = what_to_show;