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LibJS: Add spec comments to ObjectPrototype
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@linusg
linusg committed Apr 15, 2023
1 parent 50cb4f0 commit b1ea436
Showing 1 changed file with 149 additions and 70 deletions.
219 changes: 149 additions & 70 deletions Userland/Libraries/LibJS/Runtime/ObjectPrototype.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -60,11 +60,74 @@ ThrowCompletionOr<bool> ObjectPrototype::internal_set_prototype_of(Object* proto
// 20.1.3.2 Object.prototype.hasOwnProperty ( V ), https://tc39.es/ecma262/#sec-object.prototype.hasownproperty
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::has_own_property)
{
// 1. Let P be ? ToPropertyKey(V).
auto property_key = TRY(vm.argument(0).to_property_key(vm));

// 2. Let O be ? ToObject(this value).
auto this_object = TRY(vm.this_value().to_object(vm));

// 3. Return ? HasOwnProperty(O, P).
return Value(TRY(this_object->has_own_property(property_key)));
}

// 20.1.3.3 Object.prototype.isPrototypeOf ( V ), https://tc39.es/ecma262/#sec-object.prototype.isprototypeof
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::is_prototype_of)
{
auto object_argument = vm.argument(0);

// 1. If V is not an Object, return false.
if (!object_argument.is_object())
return Value(false);
auto* object = &object_argument.as_object();

// 2. Let O be ? ToObject(this value).
auto this_object = TRY(vm.this_value().to_object(vm));

// 3. Repeat,
for (;;) {
// a. Set V to ? V.[[GetPrototypeOf]]().
object = TRY(object->internal_get_prototype_of());

// b. If V is null, return false.
if (!object)
return Value(false);

// c. If SameValue(O, V) is true, return true.
if (same_value(this_object, object))
return Value(true);
}
}

// 20.1.3.4 Object.prototype.propertyIsEnumerable ( V ), https://tc39.es/ecma262/#sec-object.prototype.propertyisenumerable
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::property_is_enumerable)
{
// 1. Let P be ? ToPropertyKey(V).
auto property_key = TRY(vm.argument(0).to_property_key(vm));

// 2. Let O be ? ToObject(this value).
auto this_object = TRY(vm.this_value().to_object(vm));

// 3. Let desc be ? O.[[GetOwnProperty]](P).
auto property_descriptor = TRY(this_object->internal_get_own_property(property_key));

// 4. If desc is undefined, return false.
if (!property_descriptor.has_value())
return Value(false);

// 5. Return desc.[[Enumerable]].
return Value(*property_descriptor->enumerable);
}

// 20.1.3.5 Object.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] ), https://tc39.es/ecma262/#sec-object.prototype.tolocalestring
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::to_locale_string)
{
// 1. Let O be the this value.
auto this_value = vm.this_value();

// 2. Return ? Invoke(O, "toString").
return this_value.invoke(vm, vm.names.toString);
}

// 20.1.3.6 Object.prototype.toString ( ), https://tc39.es/ecma262/#sec-object.prototype.tostring
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::to_string)
{
Expand Down Expand Up @@ -133,153 +196,169 @@ JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::to_string)
return PrimitiveString::create(vm, DeprecatedString::formatted("[object {}]", tag));
}

// 20.1.3.5 Object.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] ), https://tc39.es/ecma262/#sec-object.prototype.tolocalestring
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::to_locale_string)
{
auto this_value = vm.this_value();
return this_value.invoke(vm, vm.names.toString);
}

// 20.1.3.7 Object.prototype.valueOf ( ), https://tc39.es/ecma262/#sec-object.prototype.valueof
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::value_of)
{
// 1. Return ? ToObject(this value).
return TRY(vm.this_value().to_object(vm));
}

// 20.1.3.4 Object.prototype.propertyIsEnumerable ( V ), https://tc39.es/ecma262/#sec-object.prototype.propertyisenumerable
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::property_is_enumerable)
// 20.1.3.8.1 get Object.prototype.__proto__, https://tc39.es/ecma262/#sec-get-object.prototype.__proto__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::proto_getter)
{
// 1. Let P be ? ToPropertyKey(V).
auto property_key = TRY(vm.argument(0).to_property_key(vm));
// 2. Let O be ? ToObject(this value).
auto this_object = TRY(vm.this_value().to_object(vm));
// 3. Let desc be ? O.[[GetOwnProperty]](P).
auto property_descriptor = TRY(this_object->internal_get_own_property(property_key));
// 4. If desc is undefined, return false.
if (!property_descriptor.has_value())
return Value(false);
// 5. Return desc.[[Enumerable]].
return Value(*property_descriptor->enumerable);
// 1. Let O be ? ToObject(this value).
auto object = TRY(vm.this_value().to_object(vm));

// 2. Return ? O.[[GetPrototypeOf]]().
return TRY(object->internal_get_prototype_of());
}

// 20.1.3.3 Object.prototype.isPrototypeOf ( V ), https://tc39.es/ecma262/#sec-object.prototype.isprototypeof
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::is_prototype_of)
// 20.1.3.8.2 set Object.prototype.__proto__, https://tc39.es/ecma262/#sec-set-object.prototype.__proto__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::proto_setter)
{
auto object_argument = vm.argument(0);
if (!object_argument.is_object())
return Value(false);
auto* object = &object_argument.as_object();
auto this_object = TRY(vm.this_value().to_object(vm));
auto proto = vm.argument(0);

for (;;) {
object = TRY(object->internal_get_prototype_of());
if (!object)
return Value(false);
if (same_value(this_object, object))
return Value(true);
// 1. Let O be ? RequireObjectCoercible(this value).
auto object = TRY(require_object_coercible(vm, vm.this_value()));

// 2. If proto is not an Object and proto is not null, return undefined.
if (!proto.is_object() && !proto.is_null())
return js_undefined();

// 3. If O is not an Object, return undefined.
if (!object.is_object())
return js_undefined();

// 4. Let status be ? O.[[SetPrototypeOf]](proto).
auto status = TRY(object.as_object().internal_set_prototype_of(proto.is_object() ? &proto.as_object() : nullptr));

// 5. If status is false, throw a TypeError exception.
if (!status) {
// FIXME: Improve/contextualize error message
return vm.throw_completion<TypeError>(ErrorType::ObjectSetPrototypeOfReturnedFalse);
}

// 6. Return undefined.
return js_undefined();
}

// B.2.2.2 Object.prototype.__defineGetter__ ( P, getter ), https://tc39.es/ecma262/#sec-object.prototype.__defineGetter__
// 20.1.3.9.1 Object.prototype.__defineGetter__ ( P, getter ), https://tc39.es/ecma262/#sec-object.prototype.__defineGetter__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::define_getter)
{
auto property = vm.argument(0);
auto getter = vm.argument(1);

// 1. Let O be ? ToObject(this value).
auto object = TRY(vm.this_value().to_object(vm));

auto getter = vm.argument(1);
// 2. If IsCallable(getter) is false, throw a TypeError exception.
if (!getter.is_function())
return vm.throw_completion<TypeError>(ErrorType::NotAFunction, TRY_OR_THROW_OOM(vm, getter.to_string_without_side_effects()));

// 3. Let desc be PropertyDescriptor { [[Get]]: getter, [[Enumerable]]: true, [[Configurable]]: true }.
auto descriptor = PropertyDescriptor { .get = &getter.as_function(), .enumerable = true, .configurable = true };

auto key = TRY(vm.argument(0).to_property_key(vm));
// 4. Let key be ? ToPropertyKey(P).
auto key = TRY(property.to_property_key(vm));

// 5. Perform ? DefinePropertyOrThrow(O, key, desc).
TRY(object->define_property_or_throw(key, descriptor));

// 6. Return undefined.
return js_undefined();
}

// B.2.2.3 Object.prototype.__defineSetter__ ( P, getter ), https://tc39.es/ecma262/#sec-object.prototype.__defineSetter__
// 20.1.3.9.2 Object.prototype.__defineSetter__ ( P, setter ), https://tc39.es/ecma262/#sec-object.prototype.__defineSetter__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::define_setter)
{
auto property = vm.argument(0);
auto setter = vm.argument(1);

// 1. Let O be ? ToObject(this value).
auto object = TRY(vm.this_value().to_object(vm));

auto setter = vm.argument(1);
// 2. If IsCallable(setter) is false, throw a TypeError exception.
if (!setter.is_function())
return vm.throw_completion<TypeError>(ErrorType::NotAFunction, TRY_OR_THROW_OOM(vm, setter.to_string_without_side_effects()));

// 3. Let desc be PropertyDescriptor { [[Set]]: setter, [[Enumerable]]: true, [[Configurable]]: true }.
auto descriptor = PropertyDescriptor { .set = &setter.as_function(), .enumerable = true, .configurable = true };

auto key = TRY(vm.argument(0).to_property_key(vm));
// 4. Let key be ? ToPropertyKey(P).
auto key = TRY(property.to_property_key(vm));

// 5. Perform ? DefinePropertyOrThrow(O, key, desc).
TRY(object->define_property_or_throw(key, descriptor));

// 6. Return undefined.
return js_undefined();
}

// B.2.2.4 Object.prototype.__lookupGetter__ ( P ), https://tc39.es/ecma262/#sec-object.prototype.__lookupGetter__
// 20.1.3.9.3 Object.prototype.__lookupGetter__ ( P ), https://tc39.es/ecma262/#sec-object.prototype.__lookupGetter__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::lookup_getter)
{
auto property = vm.argument(0);

// 1. Let O be ? ToObject(this value).
auto object = GCPtr { TRY(vm.this_value().to_object(vm)) };

auto key = TRY(vm.argument(0).to_property_key(vm));
// 2. Let key be ? ToPropertyKey(P).
auto key = TRY(property.to_property_key(vm));

// 3. Repeat,
while (object) {
// a. Let desc be ? O.[[GetOwnProperty]](key).
auto desc = TRY(object->internal_get_own_property(key));

// b. If desc is not undefined, then
if (desc.has_value()) {
// i. If IsAccessorDescriptor(desc) is true, return desc.[[Get]].
if (desc->is_accessor_descriptor())
return *desc->get ?: js_undefined();

// ii. Return undefined.
return js_undefined();
}

// c. Set O to ? O.[[GetPrototypeOf]]().
object = TRY(object->internal_get_prototype_of());
}

// d. If O is null, return undefined.
return js_undefined();
}

// B.2.2.5 Object.prototype.__lookupSetter__ ( P ), https://tc39.es/ecma262/#sec-object.prototype.__lookupSetter__
// 20.1.3.9.4 Object.prototype.__lookupSetter__ ( P ), https://tc39.es/ecma262/#sec-object.prototype.__lookupSetter__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::lookup_setter)
{
auto property = vm.argument(0);

// 1. Let O be ? ToObject(this value).
auto object = GCPtr { TRY(vm.this_value().to_object(vm)) };

auto key = TRY(vm.argument(0).to_property_key(vm));
// 2. Let key be ? ToPropertyKey(P).
auto key = TRY(property.to_property_key(vm));

// 3. Repeat,
while (object) {
// a. Let desc be ? O.[[GetOwnProperty]](key).
auto desc = TRY(object->internal_get_own_property(key));

// b. If desc is not undefined, then
if (desc.has_value()) {
// i. If IsAccessorDescriptor(desc) is true, return desc.[[Set]].
if (desc->is_accessor_descriptor())
return *desc->set ?: js_undefined();

// ii. Return undefined.
return js_undefined();
}

// c. Set O to ? O.[[GetPrototypeOf]]().
object = TRY(object->internal_get_prototype_of());
}

return js_undefined();
}

// B.2.2.1.1 get Object.prototype.__proto__, https://tc39.es/ecma262/#sec-get-object.prototype.__proto__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::proto_getter)
{
auto object = TRY(vm.this_value().to_object(vm));
return TRY(object->internal_get_prototype_of());
}

// B.2.2.1.2 set Object.prototype.__proto__, https://tc39.es/ecma262/#sec-set-object.prototype.__proto__
JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::proto_setter)
{
auto object = TRY(require_object_coercible(vm, vm.this_value()));

auto proto = vm.argument(0);
if (!proto.is_object() && !proto.is_null())
return js_undefined();

if (!object.is_object())
return js_undefined();

auto status = TRY(object.as_object().internal_set_prototype_of(proto.is_object() ? &proto.as_object() : nullptr));
if (!status) {
// FIXME: Improve/contextualize error message
return vm.throw_completion<TypeError>(ErrorType::ObjectSetPrototypeOfReturnedFalse);
}
// d. If O is null, return undefined.
return js_undefined();
}

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