package.helpers.isPropertyDescriptor.js Maven / Gradle / Ivy

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ECMAScript spec abstract operations.

There is a newer version: 1.22.3

'use strict';

var GetIntrinsic = require('get-intrinsic');

var has = require('has');
var $TypeError = GetIntrinsic('%TypeError%');

module.exports = function IsPropertyDescriptor(ES, Desc) {
	if (ES.Type(Desc) !== 'Object') {
		return false;
	}
	var allowed = {
		'[[Configurable]]': true,
		'[[Enumerable]]': true,
		'[[Get]]': true,
		'[[Set]]': true,
		'[[Value]]': true,
		'[[Writable]]': true
	};

	for (var key in Desc) { // eslint-disable-line no-restricted-syntax
		if (has(Desc, key) && !allowed[key]) {
			return false;
		}
	}

	if (ES.IsDataDescriptor(Desc) && ES.IsAccessorDescriptor(Desc)) {
		throw new $TypeError('Property Descriptors may not be both accessor and data descriptors');
	}
	return true;
};