core-js/internals/to-absolute-index.js

'use strict';
var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');

var max = Math.max;
var min = Math.min;

// Helper for a popular repeating case of the spec:
// Let integer be ? ToInteger(index).
// If integer < 0, let result be max((length + integer), 0); else let result be min(integer, length).
module.exports = function (index, length) {
  var integer = toIntegerOrInfinity(index);
  return integer < 0 ? max(integer + length, 0) : min(integer, length);
};