main repo

node_modules/es-abstract/2022/AdvanceStringIndex.js

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+'use strict';
+
+var CodePointAt = require('./CodePointAt');
+
+var isInteger = require('../helpers/isInteger');
+var MAX_SAFE_INTEGER = require('../helpers/maxSafeInteger');
+
+var $TypeError = require('es-errors/type');
+
+// https://262.ecma-international.org/12.0/#sec-advancestringindex
+
+module.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]]'];
+};