Parse URL fallback

no-deps-url-parse.js

// https://github.com/shm-open/utilities/blob/master/src/url.ts?cool#L52
function parseURL(url, base) {
    let rest = url;
    const reProtocol = /^([a-z][a-z0-9.+-]*:)?(\/\/)?([\S\s]*)/i;
    // extract protocol
    const protocolMatch = reProtocol.exec(url);
    let protocol = protocolMatch[1]?.toLowerCase() ?? '';
    const hasSlashes = !!protocolMatch[2];
    // eslint-disable-next-line prefer-destructuring
    rest = protocolMatch[3];

    // extract hash & query
    let hash;
    // eslint-disable-next-line prefer-const
    [rest, hash] = sliceBy(rest, '#', true);
    let search;
    // eslint-disable-next-line prefer-const
    [rest, search] = sliceBy(rest, '?', true);

    // extract host & auth
    let wholeHost = '';
    if (hasSlashes) {
        [wholeHost, rest] = sliceBy(rest, '/', true);
    }
    const [auth, host] = sliceBy(wholeHost, '@', false, true);
    let [username, password] = sliceBy(auth, ':');
    let [hostname, port] = sliceBy(host, ':');

    // apply base url
    if (!protocol && !hostname && base) {
        const ref = parseURL(base);
        protocol = ref.protocol;
        username = ref.username;
        password = ref.password;
        hostname = ref.hostname;
        port = ref.port;
        if (hostname && rest && rest[0] !== '/') {
            rest = `/${rest}`;
        }
    }

    return {
        protocol,
        username,
        password,
        hostname,
        port,
        // has hostname, default to '/'
        pathname: !rest && hostname ? '/' : rest,
        search,
        hash,
    };
}

function sliceBy(
    text,
    delimiter,
    include = false,
    fromBack = false,
) {
    const index = text.indexOf(delimiter);
    if (index === -1) {
        if (fromBack) {
            return ['', text];
        }
        return [text, ''];
    }

    return [
        text.slice(0, index) + (include && fromBack ? delimiter : ''),
        (include && !fromBack ? delimiter : '') + text.slice(index + delimiter.length),
    ];
}