Prefetch sites on idle and prerender sites on hover

script.js

import { listen } from 'quicklink';
import ProbaClick from 'probaclick';

// Quicklink
window.addEventListener('load', () => {
    listen({
        ignores: [(uri) => uri.includes('wp-') || uri.includes('.pdf') || uri.includes('.zip')],
    });
});

// Prerender
ProbaClick('a', {
    delay: 300,
    callback: function (link) {
        maybeMakeHint({
            link,
            type: 'prerender',
        });
    },
});

let hasBeen = {
    prefetch: [],
    prerender: [],
};

export const makeHint = (href, type) => {
    let link = document.createElement('link');
    link.setAttribute('rel', type);
    link.setAttribute('href', href);
    document.head.appendChild(link);
    return href;
};

const isExternalLink = (href) => {
    return !href.match(/^\//) && !href.includes(window.location.host);
};

const maybeMakeHint = ({ link, type } = {}) => {
    let href = link.getAttribute('href').split('?')[0];

    if (isExternalLink(href)) return;
    if (hasBeen[type].includes(href)) return;

    hasBeen[type].push(makeHint(href, type));
};