source: imaps-frontend/node_modules/es-abstract/2021/StringIndexOf.js@ d565449

'use strict';

var callBound = require('call-bind/callBound');

var $TypeError = require('es-errors/type');

var isInteger = require('../helpers/isInteger');

var $slice = callBound('String.prototype.slice');

// https://262.ecma-international.org/12.0/#sec-stringindexof

module.exports = function StringIndexOf(string, searchValue, fromIndex) {
        if (typeof string !== 'string') {
                throw new $TypeError('Assertion failed: `string` must be a String');
        }
        if (typeof searchValue !== 'string') {
                throw new $TypeError('Assertion failed: `searchValue` must be a String');
        }
        if (!isInteger(fromIndex) || fromIndex < 0) {
                throw new $TypeError('Assertion failed: `fromIndex` must be a non-negative integer');
        }

        var len = string.length;
        if (searchValue === '' && fromIndex <= len) {
                return fromIndex;
        }

        var searchLen = searchValue.length;
        for (var i = fromIndex; i <= (len - searchLen); i += 1) {
                var candidate = $slice(string, i, i + searchLen);
                if (candidate === searchValue) {
                        return i;
                }
        }
        return -1;
};