| 123456789101112131415161718192021222324252627282930 | 'use strict';var CodePointAt = require('./CodePointAt');var $TypeError = require('es-errors/type');var isInteger = require('math-intrinsics/isInteger');var MAX_SAFE_INTEGER = require('math-intrinsics/constants/maxSafeInteger');// https://262.ecma-international.org/12.0/#sec-advancestringindexmodule.exports = function AdvanceStringIndex(S, index, unicode) {	if (typeof S !== 'string') {		throw new $TypeError('Assertion failed: `S` must be a String');	}	if (!isInteger(index) || index < 0 || index > MAX_SAFE_INTEGER) {		throw new $TypeError('Assertion failed: `length` must be an integer >= 0 and <= 2**53');	}	if (typeof unicode !== 'boolean') {		throw new $TypeError('Assertion failed: `unicode` must be a Boolean');	}	if (!unicode) {		return index + 1;	}	var length = S.length;	if ((index + 1) >= length) {		return index + 1;	}	var cp = CodePointAt(S, index);	return index + cp['[[CodeUnitCount]]'];};
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