ValidateAndApplyPropertyDescriptor.js
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'use strict';
var GetIntrinsic = require('get-intrinsic');
var $TypeError = GetIntrinsic('%TypeError%');
var DefineOwnProperty = require('../helpers/DefineOwnProperty');
var isFullyPopulatedPropertyDescriptor = require('../helpers/isFullyPopulatedPropertyDescriptor');
var isPropertyDescriptor = require('../helpers/isPropertyDescriptor');
var FromPropertyDescriptor = require('./FromPropertyDescriptor');
var IsAccessorDescriptor = require('./IsAccessorDescriptor');
var IsDataDescriptor = require('./IsDataDescriptor');
var IsGenericDescriptor = require('./IsGenericDescriptor');
var IsPropertyKey = require('./IsPropertyKey');
var SameValue = require('./SameValue');
var Type = require('./Type');
// https://262.ecma-international.org/13.0/#sec-validateandapplypropertydescriptor
// see https://github.com/tc39/ecma262/pull/2468 for ES2022 changes
// eslint-disable-next-line max-lines-per-function, max-statements, max-params
module.exports = function ValidateAndApplyPropertyDescriptor(O, P, extensible, Desc, current) {
var oType = Type(O);
if (oType !== 'Undefined' && oType !== 'Object') {
throw new $TypeError('Assertion failed: O must be undefined or an Object');
}
if (!IsPropertyKey(P)) {
throw new $TypeError('Assertion failed: P must be a Property Key');
}
if (Type(extensible) !== 'Boolean') {
throw new $TypeError('Assertion failed: extensible must be a Boolean');
}
if (!isPropertyDescriptor({
Type: Type,
IsDataDescriptor: IsDataDescriptor,
IsAccessorDescriptor: IsAccessorDescriptor
}, Desc)) {
throw new $TypeError('Assertion failed: Desc must be a Property Descriptor');
}
if (Type(current) !== 'Undefined' && !isPropertyDescriptor({
Type: Type,
IsDataDescriptor: IsDataDescriptor,
IsAccessorDescriptor: IsAccessorDescriptor
}, current)) {
throw new $TypeError('Assertion failed: current must be a Property Descriptor, or undefined');
}
if (Type(current) === 'Undefined') { // step 2
if (!extensible) {
return false; // step 2.a
}
if (oType === 'Undefined') {
return true; // step 2.b
}
if (IsAccessorDescriptor(Desc)) { // step 2.c
return DefineOwnProperty(
IsDataDescriptor,
SameValue,
FromPropertyDescriptor,
O,
P,
Desc
);
}
// step 2.d
return DefineOwnProperty(
IsDataDescriptor,
SameValue,
FromPropertyDescriptor,
O,
P,
{
'[[Configurable]]': !!Desc['[[Configurable]]'],
'[[Enumerable]]': !!Desc['[[Enumerable]]'],
'[[Value]]': Desc['[[Value]]'],
'[[Writable]]': !!Desc['[[Writable]]']
}
);
}
// 3. Assert: current is a fully populated Property Descriptor.
if (!isFullyPopulatedPropertyDescriptor({
IsAccessorDescriptor: IsAccessorDescriptor,
IsDataDescriptor: IsDataDescriptor
}, current)) {
throw new $TypeError('`current`, when present, must be a fully populated and valid Property Descriptor');
}
// 4. If every field in Desc is absent, return true.
// this can't really match the assertion that it's a Property Descriptor in our JS implementation
// 5. If current.[[Configurable]] is false, then
if (!current['[[Configurable]]']) {
if ('[[Configurable]]' in Desc && Desc['[[Configurable]]']) {
// step 5.a
return false;
}
if ('[[Enumerable]]' in Desc && !SameValue(Desc['[[Enumerable]]'], current['[[Enumerable]]'])) {
// step 5.b
return false;
}
if (!IsGenericDescriptor(Desc) && !SameValue(IsAccessorDescriptor(Desc), IsAccessorDescriptor(current))) {
// step 5.c
return false;
}
if (IsAccessorDescriptor(current)) { // step 5.d
if ('[[Get]]' in Desc && !SameValue(Desc['[[Get]]'], current['[[Get]]'])) {
return false;
}
if ('[[Set]]' in Desc && !SameValue(Desc['[[Set]]'], current['[[Set]]'])) {
return false;
}
} else if (!current['[[Writable]]']) { // step 5.e
if ('[[Writable]]' in Desc && Desc['[[Writable]]']) {
return false;
}
if ('[[Value]]' in Desc && !SameValue(Desc['[[Value]]'], current['[[Value]]'])) {
return false;
}
}
}
// 6. If O is not undefined, then
if (oType !== 'Undefined') {
var configurable;
var enumerable;
if (IsDataDescriptor(current) && IsAccessorDescriptor(Desc)) { // step 6.a
configurable = ('[[Configurable]]' in Desc ? Desc : current)['[[Configurable]]'];
enumerable = ('[[Enumerable]]' in Desc ? Desc : current)['[[Enumerable]]'];
// Replace the property named P of object O with an accessor property having [[Configurable]] and [[Enumerable]] attributes as described by current and each other attribute set to its default value.
return DefineOwnProperty(
IsDataDescriptor,
SameValue,
FromPropertyDescriptor,
O,
P,
{
'[[Configurable]]': !!configurable,
'[[Enumerable]]': !!enumerable,
'[[Get]]': ('[[Get]]' in Desc ? Desc : current)['[[Get]]'],
'[[Set]]': ('[[Set]]' in Desc ? Desc : current)['[[Set]]']
}
);
} else if (IsAccessorDescriptor(current) && IsDataDescriptor(Desc)) {
configurable = ('[[Configurable]]' in Desc ? Desc : current)['[[Configurable]]'];
enumerable = ('[[Enumerable]]' in Desc ? Desc : current)['[[Enumerable]]'];
// i. Replace the property named P of object O with a data property having [[Configurable]] and [[Enumerable]] attributes as described by current and each other attribute set to its default value.
return DefineOwnProperty(
IsDataDescriptor,
SameValue,
FromPropertyDescriptor,
O,
P,
{
'[[Configurable]]': !!configurable,
'[[Enumerable]]': !!enumerable,
'[[Value]]': ('[[Value]]' in Desc ? Desc : current)['[[Value]]'],
'[[Writable]]': !!('[[Writable]]' in Desc ? Desc : current)['[[Writable]]']
}
);
}
// For each field of Desc that is present, set the corresponding attribute of the property named P of object O to the value of the field.
return DefineOwnProperty(
IsDataDescriptor,
SameValue,
FromPropertyDescriptor,
O,
P,
Desc
);
}
return true; // step 7
};