RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 08:48:11 +00:00
Code Issues Activity Actions

LibJS: Add Object.defineProperty() and start caring about attributes

Browse source 
We now care (a little bit) about the "configurable" and "writable"
property attributes.

Property attributes are stored together with the property name in
the Shape object. Forward transitions are not attribute-savvy and will
cause poor Shape reuse in the case of multiple same-name properties
with different attributes.

Oh, and this patch also adds Object.getOwnPropertyDescriptor() :^)
This commit is contained in:
Andreas Kling 2020-04-09 22:15:26 +02:00
parent 1570e67881
commit e6d920d87d
7 changed files with 121 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

46
Libraries/LibJS/Runtime/ObjectConstructor.cpp
View file

@ -28,6 +28,7 @@
#include <LibJS/Heap/Heap.h>
#include <LibJS/Interpreter.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/ObjectConstructor.h>
#include <LibJS/Runtime/Shape.h>
@ -37,6 +38,8 @@ ObjectConstructor::ObjectConstructor()
{
put("prototype", interpreter().object_prototype());
put_native_function("defineProperty", define_property, 3);
put_native_function("getOwnPropertyDescriptor", get_own_property_descriptor, 2);
put_native_function("getOwnPropertyNames", get_own_property_names, 1);
put_native_function("getPrototypeOf", get_prototype_of, 1);
put_native_function("setPrototypeOf", set_prototype_of, 2);
@ -88,8 +91,6 @@ Value ObjectConstructor::set_prototype_of(Interpreter& interpreter)
{
if (interpreter.argument_count() < 2)
return {};
if (!interpreter.argument(0).is_object())
return {};
auto* object = interpreter.argument(0).to_object(interpreter.heap());
if (interpreter.exception())
return {};
@ -97,4 +98,45 @@ Value ObjectConstructor::set_prototype_of(Interpreter& interpreter)
return {};
}
Value ObjectConstructor::get_own_property_descriptor(Interpreter& interpreter)
{
if (interpreter.argument_count() < 2)
return interpreter.throw_exception<Error>("TypeError", "Object.getOwnPropertyDescriptor() needs 2 arguments");
if (!interpreter.argument(0).is_object())
return interpreter.throw_exception<Error>("TypeError", "Object argument is not an object");
auto& object = interpreter.argument(0).as_object();
auto metadata = object.shape().lookup(interpreter.argument(1).to_string());
if (!metadata.has_value())
return js_undefined();
auto* descriptor = interpreter.heap().allocate<Object>();
descriptor->put("configurable", Value(!!(metadata.value().attributes & Attribute::Configurable)));
descriptor->put("enumerable", Value(!!(metadata.value().attributes & Attribute::Enumerable)));
descriptor->put("writable", Value(!!(metadata.value().attributes & Attribute::Writable)));
descriptor->put("value", object.get(interpreter.argument(1).to_string()).value_or(js_undefined()));
return descriptor;
}
Value ObjectConstructor::define_property(Interpreter& interpreter)
{
if (interpreter.argument_count() < 3)
return interpreter.throw_exception<Error>("TypeError", "Object.defineProperty() needs 3 arguments");
if (!interpreter.argument(0).is_object())
return interpreter.throw_exception<Error>("TypeError", "Object argument is not an object");
if (!interpreter.argument(2).is_object())
return interpreter.throw_exception<Error>("TypeError", "Descriptor argument is not an object");
auto& object = interpreter.argument(0).as_object();
auto& descriptor = interpreter.argument(2).as_object();
Value value = descriptor.get("value").value_or(js_undefined());
u8 configurable = descriptor.get("configurable").value_or(Value(false)).to_boolean() * Attribute::Configurable;
u8 enumerable = descriptor.get("enumerable").value_or(Value(false)).to_boolean() * Attribute::Enumerable;
u8 writable = descriptor.get("writable").value_or(Value(false)).to_boolean() * Attribute::Writable;
u8 attributes = configurable | enumerable | writable;
dbg() << "Defining new property " << interpreter.argument(1).to_string() << " with descriptor { " << configurable << ", " << enumerable << ", " << writable << ", attributes=" << attributes << " }";
object.put_own_property(object, interpreter.argument(1).to_string(), attributes, value, PutOwnPropertyMode::DefineProperty);
return &object;
}
}