odin-js-fundamentals-part-5/node_modules/es-abstract/2020/IsValidIntegerIndex.js

31 lines
797 B
JavaScript

'use strict';
var GetIntrinsic = require('get-intrinsic');
var $TypeError = GetIntrinsic('%TypeError%');
var IsInteger = require('./IsInteger');
var isNegativeZero = require('../helpers/isNegativeZero');
var typedArrayBuffer = require('typed-array-buffer');
// https://262.ecma-international.org/11.0/#sec-isvalidintegerindex
module.exports = function IsValidIntegerIndex(O, index) {
// Assert: O is an Integer-Indexed exotic object.
typedArrayBuffer(O); // step 1
if (typeof index !== 'number') {
throw new $TypeError('Assertion failed: Type(index) is not Number'); // step 2
}
if (!IsInteger(index)) { return false; } // step 3
if (isNegativeZero(index)) { return false; } // step 4
if (index < 0 || index >= O.length) { return false; } // step 5
return true; // step 6
};