source: imaps-frontend/node_modules/es-abstract/2023/WordCharacters.js

'use strict';

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

var callBound = require('call-bind/callBound');
var $indexOf = callBound('String.prototype.indexOf', true);

var Canonicalize = require('./Canonicalize');

var caseFolding = require('../helpers/caseFolding.json');
var forEach = require('../helpers/forEach');
var isRegExpRecord = require('../helpers/records/regexp-record');
var OwnPropertyKeys = require('../helpers/OwnPropertyKeys');

var basicWordChars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_'; // step 1

// https://262.ecma-international.org/14.0/#sec-runtime-semantics-wordcharacters-abstract-operation

module.exports = function WordCharacters(rer) {
        if (!isRegExpRecord(rer)) {
                throw new $TypeError('Assertion failed: `rer` must be a RegExp Record');
        }

        var extraWordChars = '';
        forEach(OwnPropertyKeys(caseFolding.C), function (c) {
                if (
                        $indexOf(basicWordChars, c) === -1 // c not in A
                        && $indexOf(basicWordChars, Canonicalize(rer, c)) > -1 // canonicalized c IS in A
                ) {
                        extraWordChars += caseFolding.C[c]; // step 3
                }
        });
        forEach(OwnPropertyKeys(caseFolding.S), function (c) {
                if (
                        $indexOf(basicWordChars, c) === -1 // c not in A
                        && $indexOf(basicWordChars, Canonicalize(rer, c)) > -1 // canonicalized c IS in A
                ) {
                        extraWordChars += caseFolding.S[c]; // step 3
                }
        });

        if ((!rer['[[Unicode]]'] || !rer['[[IgnoreCase]]']) && extraWordChars.length > 0) {
                throw new $TypeError('Assertion failed: `extraWordChars` must be empty when `rer.[[IgnoreCase]]` and `rer.[[Unicode]]` are not both true'); // step 3
        }

        return basicWordChars + extraWordChars; // step 4
};