URL Parser and Media Promise

url.js

export function encodeURLParams(params) {
    return Object
        .entries(params)
        .sort((a, b) => a[0] - b[0])
        .reduce((search, entry) => [
            ...search,
            entry
                .map(encodeURIComponent)
                .join('=')
        ], [])
        .join('&');
}

export function composeURL(base, params) {
    return params
        ? `${base}?${encodeURLParams(params)}`
        : base;
}

export function parseURLSearch(search) {
    return search
        .substring(1)
        .split('&')
        .reduce((params, param) => {
            const entry = param
                .split('=')
                .map(decodeURIComponent);
            return {
                ...params,
                [entry[0]]: entry[1]
            };
        }, {});
}

export default function parseURL(url) {
    const parser = document.createElement('a');
    parser.href = url;
    const {
        hash,
        host,
        hostname,
        href,
        origin,
        pathname,
        port,
        protocol,
        search
    } = parser;
    return {
        hash,
        host,
        hostname,
        href,
        origin,
        pathname,
        port,
        protocol,
        search,
        path: origin + pathname,
        params: parseURLSearch(search),
        getImg: (t = 0) => new Promise((resolve, reject) => {
            const image = document.createElement('img'),
                timeout = t && setTimeout(() => {
                    image.src = "//!!!/timeout";
                    reject("Image timed out.");
                }, t);
            image.onload = e => {
                timeout && clearTimeout(timeout);
                resolve(e.target);
            };
            image.onerror = e => {
                timeout && clearTimeout(timeout);
                reject(e);
            };
            image.src = href;
        }),
        getVideo: (t = 0) => new Promise((resolve, reject) => {
            const video = document.createElement('video'),
                timeout = t && setTimeout(() => {
                    video.src = "//!!!/timeout";
                    reject("Video timed out.");
                }, t);
            video.preload = "metadata";
            video.onloadedmetadata = e => {
                timeout && clearTimeout(timeout);
                resolve(e.target);
            };
            video.onerror = e => {
                timeout && clearTimeout(timeout);
                reject(e);
            };
            video.src = href;
        })
    };
}