'use strict';
|
|
var GetIntrinsic = require('get-intrinsic');
|
var callBound = require('call-bind/callBound');
|
|
var $TypeError = GetIntrinsic('%TypeError%');
|
|
var IsIntegralNumber = require('./IsIntegralNumber');
|
var Type = require('./Type');
|
|
var $slice = callBound('String.prototype.slice');
|
|
// https://ecma-international.org/ecma-262/12.0/#sec-stringindexof
|
|
module.exports = function StringIndexOf(string, searchValue, fromIndex) {
|
if (Type(string) !== 'String') {
|
throw new $TypeError('Assertion failed: `string` must be a String');
|
}
|
if (Type(searchValue) !== 'String') {
|
throw new $TypeError('Assertion failed: `searchValue` must be a String');
|
}
|
if (!IsIntegralNumber(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;
|
};
|
