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/*
* Copyright (c) 2021-2022, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/FunctionObject.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/Object.h>
#include <LibJS/Runtime/PropertyDescriptor.h>
#include <LibJS/Runtime/Value.h>
namespace JS {
// 6.2.5.1 IsAccessorDescriptor ( Desc ), https://tc39.es/ecma262/#sec-isaccessordescriptor
bool PropertyDescriptor::is_accessor_descriptor() const
{
// 1. If Desc is undefined, return false.
// 2. If Desc has a [[Get]] field, return true.
if (get.has_value())
return true;
// 3. If Desc has a [[Set]] field, return true.
if (set.has_value())
return true;
// 4. Return false.
return false;
}
// 6.2.5.2 IsDataDescriptor ( Desc ), https://tc39.es/ecma262/#sec-isdatadescriptor
bool PropertyDescriptor::is_data_descriptor() const
{
// 1. If Desc is undefined, return false.
// 2. If Desc has a [[Value]] field, return true.
if (value.has_value())
return true;
// 3. If Desc has a [[Writable]] field, return true.
if (writable.has_value())
return true;
// 4. Return false.
return false;
}
// 6.2.5.3 IsGenericDescriptor ( Desc ), https://tc39.es/ecma262/#sec-isgenericdescriptor
bool PropertyDescriptor::is_generic_descriptor() const
{
// 1. If Desc is undefined, return false.
// 2. If IsAccessorDescriptor(Desc) is true, return false.
if (is_accessor_descriptor())
return false;
// 3. If IsDataDescriptor(Desc) is true, return false.
if (is_data_descriptor())
return false;
// 4. Return true.
return true;
}
// 6.2.5.4 FromPropertyDescriptor ( Desc ), https://tc39.es/ecma262/#sec-frompropertydescriptor
Value from_property_descriptor(VM& vm, Optional<PropertyDescriptor> const& property_descriptor)
{
auto& realm = *vm.current_realm();
if (!property_descriptor.has_value())
return js_undefined();
auto* object = Object::create(realm, realm.intrinsics().object_prototype());
if (property_descriptor->value.has_value())
MUST(object->create_data_property_or_throw(vm.names.value, *property_descriptor->value));
if (property_descriptor->writable.has_value())
MUST(object->create_data_property_or_throw(vm.names.writable, Value(*property_descriptor->writable)));
if (property_descriptor->get.has_value())
MUST(object->create_data_property_or_throw(vm.names.get, *property_descriptor->get ? Value(*property_descriptor->get) : js_undefined()));
if (property_descriptor->set.has_value())
MUST(object->create_data_property_or_throw(vm.names.set, *property_descriptor->set ? Value(*property_descriptor->set) : js_undefined()));
if (property_descriptor->enumerable.has_value())
MUST(object->create_data_property_or_throw(vm.names.enumerable, Value(*property_descriptor->enumerable)));
if (property_descriptor->configurable.has_value())
MUST(object->create_data_property_or_throw(vm.names.configurable, Value(*property_descriptor->configurable)));
return object;
}
// 6.2.5.5 ToPropertyDescriptor ( Obj ), https://tc39.es/ecma262/#sec-topropertydescriptor
ThrowCompletionOr<PropertyDescriptor> to_property_descriptor(VM& vm, Value argument)
{
// 1. If Type(Obj) is not Object, throw a TypeError exception.
if (!argument.is_object())
return vm.throw_completion<TypeError>(ErrorType::NotAnObject, argument.to_string_without_side_effects());
auto& object = argument.as_object();
// 2. Let desc be a new Property Descriptor that initially has no fields.
PropertyDescriptor descriptor;
// 3. Let hasEnumerable be ? HasProperty(Obj, "enumerable").
auto has_enumerable = TRY(object.has_property(vm.names.enumerable));
// 4. If hasEnumerable is true, then
if (has_enumerable) {
// a. Let enumerable be ToBoolean(? Get(Obj, "enumerable")).
auto enumerable = TRY(object.get(vm.names.enumerable)).to_boolean();
// b. Set desc.[[Enumerable]] to enumerable.
descriptor.enumerable = enumerable;
}
// 5. Let hasConfigurable be ? HasProperty(Obj, "configurable").
auto has_configurable = TRY(object.has_property(vm.names.configurable));
// 6. If hasConfigurable is true, then
if (has_configurable) {
// a. Let configurable be ToBoolean(? Get(Obj, "configurable")).
auto configurable = TRY(object.get(vm.names.configurable)).to_boolean();
// b. Set desc.[[Configurable]] to configurable.
descriptor.configurable = configurable;
}
// 7. Let hasValue be ? HasProperty(Obj, "value").
auto has_value = TRY(object.has_property(vm.names.value));
// 8. If hasValue is true, then
if (has_value) {
// a. Let value be ? Get(Obj, "value").
auto value = TRY(object.get(vm.names.value));
// b. Set desc.[[Value]] to value.
descriptor.value = value;
}
// 9. Let hasWritable be ? HasProperty(Obj, "writable").
auto has_writable = TRY(object.has_property(vm.names.writable));
// 10. If hasWritable is true, then
if (has_writable) {
// a. Let writable be ToBoolean(? Get(Obj, "writable")).
auto writable = TRY(object.get(vm.names.writable)).to_boolean();
// b. Set desc.[[Writable]] to writable.
descriptor.writable = writable;
}
// 11. Let hasGet be ? HasProperty(Obj, "get").
auto has_get = TRY(object.has_property(vm.names.get));
// 12. If hasGet is true, then
if (has_get) {
// a. Let getter be ? Get(Obj, "get").
auto getter = TRY(object.get(vm.names.get));
// b. If IsCallable(getter) is false and getter is not undefined, throw a TypeError exception.
if (!getter.is_function() && !getter.is_undefined())
return vm.throw_completion<TypeError>(ErrorType::AccessorBadField, "get");
// c. Set desc.[[Get]] to getter.
descriptor.get = getter.is_function() ? &getter.as_function() : nullptr;
}
// 13. Let hasSet be ? HasProperty(Obj, "set").
auto has_set = TRY(object.has_property(vm.names.set));
// 14. If hasSet is true, then
if (has_set) {
// a. Let setter be ? Get(Obj, "set").
auto setter = TRY(object.get(vm.names.set));
// b. If IsCallable(setter) is false and setter is not undefined, throw a TypeError exception.
if (!setter.is_function() && !setter.is_undefined())
return vm.throw_completion<TypeError>(ErrorType::AccessorBadField, "set");
// c. Set desc.[[Set]] to setter.
descriptor.set = setter.is_function() ? &setter.as_function() : nullptr;
}
// 15. If desc has a [[Get]] field or desc has a [[Set]] field, then
if (descriptor.get.has_value() || descriptor.set.has_value()) {
// a. If desc has a [[Value]] field or desc has a [[Writable]] field, throw a TypeError exception.
if (descriptor.value.has_value() || descriptor.writable.has_value())
return vm.throw_completion<TypeError>(ErrorType::AccessorValueOrWritable);
}
// 16. Return desc.
return descriptor;
}
// 6.2.5.6 CompletePropertyDescriptor ( Desc ), https://tc39.es/ecma262/#sec-completepropertydescriptor
void PropertyDescriptor::complete()
{
if (is_generic_descriptor() || is_data_descriptor()) {
if (!value.has_value())
value = Value {};
if (!writable.has_value())
writable = false;
} else {
if (!get.has_value())
get = nullptr;
if (!set.has_value())
set = nullptr;
}
if (!enumerable.has_value())
enumerable = false;
if (!configurable.has_value())
configurable = false;
}
// Non-standard, just a convenient way to get from three Optional<bool> to PropertyAttributes.
PropertyAttributes PropertyDescriptor::attributes() const
{
u8 attributes = 0;
if (writable.value_or(false))
attributes |= Attribute::Writable;
if (enumerable.value_or(false))
attributes |= Attribute::Enumerable;
if (configurable.value_or(false))
attributes |= Attribute::Configurable;
return { attributes };
}
}
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