IRC URL parsing in JavaScript

ircUrlParts.js

export function ircUrlParts (ircUrl) {
    // http://tools.ietf.org/html/draft-butcher-irc-url-04
    if (!ircUrl) {
        return;
    }
    var urlParts = ircUrl.split('://');
    if (!urlParts[1]) {
        return;
    }
    var protocol = urlParts[0];
    var bufferParts = urlParts[1].split('#');
    var rootPart, bufferString;
    if (bufferParts[0].indexOf('/') === -1) {
        // No slash used as channel delimiter, just hash
        rootPart = bufferParts.shift();
        if (bufferParts.length) {
            bufferString = '#' + bufferParts.join('#');
        }
    } else {
        bufferParts = urlParts[1].split('/');
        rootPart = bufferParts.shift();
        if (bufferParts.length) {
            bufferString = bufferParts.join('/');
        }
    }

    // Convert +6697 to ircs port
    var rootPartSplit = rootPart.split(':');
    if (rootPartSplit[1]) {
        var rootPortSSL = rootPartSplit[1].match(/^\+(\d+)$/);
        if (rootPortSSL) {
            protocol = 'ircs';
            rootPart = rootPartSplit[0] + ':' + rootPortSSL[1];
        }
    }
    if (protocol === 'ircs') {
        rootPart = protocol + '://' + rootPart;
    }
    
    var url = rootPart;
    var label;
    if (bufferString) {
        var bufferStringParts = bufferString.split(',');
        label = bufferStringParts[0];
        if (bufferStringParts[1] != 'isuser' && $.inArray(label[0], ['#', '＃', '&', '+', '!']) == -1) {
            label = '#' + label;
        }
        url += '/' + label;
    }
    return {
        root: rootPart,
        label: label,
        url: url
    };
}