// https://tc39.github.io/ecma262/#sec-reflect.defineproperty
EncodedJSValue JSC_HOST_CALL reflectObjectDefineProperty(ExecState* exec)
{
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
JSValue target = exec->argument(0);
if (!target.isObject())
return JSValue::encode(throwTypeError(exec, scope, ASCIILiteral("Reflect.defineProperty requires the first argument be an object")));
auto propertyName = exec->argument(1).toPropertyKey(exec);
RETURN_IF_EXCEPTION(scope, encodedJSValue());
PropertyDescriptor descriptor;
bool success = toPropertyDescriptor(exec, exec->argument(2), descriptor);
ASSERT(!scope.exception() == success);
if (UNLIKELY(!success))
return encodedJSValue();
ASSERT((descriptor.attributes() & Accessor) || (!descriptor.isAccessorDescriptor()));
ASSERT(!scope.exception());
// Reflect.defineProperty should not throw an error when the defineOwnProperty operation fails.
bool shouldThrow = false;
JSObject* targetObject = asObject(target);
scope.release();
return JSValue::encode(jsBoolean(targetObject->methodTable(vm)->defineOwnProperty(targetObject, exec, propertyName, descriptor, shouldThrow)));
}
EncodedJSValue JSC_HOST_CALL objectConstructorDefineProperty(ExecState* exec)
{
if (!exec->argument(0).isObject())
return throwVMError(exec, createTypeError(exec, ASCIILiteral("Properties can only be defined on Objects.")));
JSObject* O = asObject(exec->argument(0));
String propertyName = exec->argument(1).toString(exec)->value(exec);
if (exec->hadException())
return JSValue::encode(jsNull());
PropertyDescriptor descriptor;
if (!toPropertyDescriptor(exec, exec->argument(2), descriptor))
return JSValue::encode(jsNull());
ASSERT((descriptor.attributes() & Accessor) || (!descriptor.isAccessorDescriptor()));
ASSERT(!exec->hadException());
O->methodTable()->defineOwnProperty(O, exec, Identifier(exec, propertyName), descriptor, true);
return JSValue::encode(O);
}
JSValue JSC_HOST_CALL objectConstructorDefineProperty(ExecState* exec, JSObject*, JSValue, const ArgList& args)
{
if (!args.at(0).isObject())
return throwError(exec, TypeError, "Properties can only be defined on Objects.");
JSObject* O = asObject(args.at(0));
UString propertyName = args.at(1).toString(exec);
if (exec->hadException())
return jsNull();
PropertyDescriptor descriptor;
if (!toPropertyDescriptor(exec, args.at(2), descriptor))
return jsNull();
ASSERT((descriptor.attributes() & (Getter | Setter)) || (!descriptor.isAccessorDescriptor()));
ASSERT(!exec->hadException());
O->defineOwnProperty(exec, Identifier(exec, propertyName), descriptor, true);
return O;
}
// http://www.ecma-international.org/ecma-262/6.0/#sec-reflect.defineproperty
EncodedJSValue JSC_HOST_CALL reflectObjectDefineProperty(ExecState* exec)
{
JSValue target = exec->argument(0);
if (!target.isObject())
return JSValue::encode(throwTypeError(exec, ASCIILiteral("Reflect.defineProperty requires the first argument be an object")));
auto propertyName = exec->argument(1).toPropertyKey(exec);
if (exec->hadException())
return JSValue::encode(jsUndefined());
PropertyDescriptor descriptor;
if (!toPropertyDescriptor(exec, exec->argument(2), descriptor))
return JSValue::encode(jsUndefined());
ASSERT((descriptor.attributes() & Accessor) || (!descriptor.isAccessorDescriptor()));
ASSERT(!exec->hadException());
// Reflect.defineProperty should not throw an error when the defineOwnProperty operation fails.
bool shouldThrow = false;
JSObject* targetObject = asObject(target);
return JSValue::encode(jsBoolean(targetObject->methodTable(exec->vm())->defineOwnProperty(targetObject, exec, propertyName, descriptor, shouldThrow)));
}
bool JSObject::defineOwnProperty(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor, bool throwException)
{
// If we have a new property we can just put it on normally
PropertyDescriptor current;
if (!getOwnPropertyDescriptor(exec, propertyName, current))
return putDescriptor(exec, this, propertyName, descriptor, descriptor.attributes(), jsUndefined());
if (descriptor.isEmpty())
return true;
if (current.equalTo(descriptor))
return true;
// Filter out invalid changes
if (!current.configurable()) {
if (descriptor.configurable()) {
if (throwException)
throwError(exec, TypeError, "Attempting to configurable attribute of unconfigurable property.");
return false;
}
if (descriptor.enumerablePresent() && descriptor.enumerable() != current.enumerable()) {
if (throwException)
throwError(exec, TypeError, "Attempting to change enumerable attribute of unconfigurable property.");
return false;
}
}
// A generic descriptor is simply changing the attributes of an existing property
if (descriptor.isGenericDescriptor()) {
if (!current.attributesEqual(descriptor)) {
deleteProperty(exec, propertyName);
putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current.value());
}
return true;
}
// Changing between a normal property or an accessor property
if (descriptor.isDataDescriptor() != current.isDataDescriptor()) {
if (!current.configurable()) {
if (throwException)
throwError(exec, TypeError, "Attempting to change access mechanism for an unconfigurable property.");
return false;
}
deleteProperty(exec, propertyName);
return putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current.value() ? current.value() : jsUndefined());
}
// Changing the value and attributes of an existing property
if (descriptor.isDataDescriptor()) {
if (!current.configurable()) {
if (!current.writable() && descriptor.writable()) {
if (throwException)
throwError(exec, TypeError, "Attempting to change writable attribute of unconfigurable property.");
return false;
}
if (!current.writable()) {
if (descriptor.value() || !JSValue::strictEqual(current.value(), descriptor.value())) {
if (throwException)
throwError(exec, TypeError, "Attempting to change value of a readonly property.");
return false;
}
}
} else if (current.attributesEqual(descriptor)) {
if (!descriptor.value())
return true;
PutPropertySlot slot;
put(exec, propertyName, descriptor.value(), slot);
if (exec->hadException())
return false;
return true;
}
deleteProperty(exec, propertyName);
return putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current.value());
}
// Changing the accessor functions of an existing accessor property
ASSERT(descriptor.isAccessorDescriptor());
if (!current.configurable()) {
if (descriptor.setterPresent() && !(current.setter() && JSValue::strictEqual(current.setter(), descriptor.setter()))) {
if (throwException)
throwError(exec, TypeError, "Attempting to change the setter of an unconfigurable property.");
return false;
}
if (descriptor.getterPresent() && !(current.getter() && JSValue::strictEqual(current.getter(), descriptor.getter()))) {
if (throwException)
throwError(exec, TypeError, "Attempting to change the getter of an unconfigurable property.");
return false;
}
}
JSValue accessor = getDirect(propertyName);
if (!accessor)
return false;
GetterSetter* getterSetter = asGetterSetter(accessor);
if (current.attributesEqual(descriptor)) {
if (descriptor.setter())
getterSetter->setSetter(asObject(descriptor.setter()));
if (descriptor.getter())
getterSetter->setGetter(asObject(descriptor.getter()));
return true;
}
deleteProperty(exec, propertyName);
unsigned attrs = current.attributesWithOverride(descriptor);
if (descriptor.setter())
attrs |= Setter;
if (descriptor.getter())
attrs |= Getter;
putDirect(propertyName, getterSetter, attrs);
return true;
}
