Userscript to reorg the package contents pages on Hackage

hackage.js

// ==UserScript==
// @name hackage
// @namespace https://github.com/instinctive/
// @description Reorganize package contents pages on Hackage.
// @include /^https?://hackage\.haskell\.org/package/[^/]*$/
// ==/UserScript==

(function() {

    function getStyleSmall(elt) {
        for (child of elt.children) {
            if (child.hasAttribute("style") &&
                child.getAttribute("style") == "font-size: small")
            {
                return child;
            }
        }
        return null;
    }

    let content = document.getElementById("content");
    let modules = document.getElementById("modules");
    let header = document.getElementById("page-header");
    let footer = document.getElementById("footer");
    let props = document.getElementById("properties");
    let descr = document.getElementById("description");
    let maint = document.getElementById("maintainer-corner");

    // TODO guard these expressions.
    let h1 = content.children[0];
    let pkg = h1.children[0];
    let ttl = h1.children[1];
    content.removeChild(h1);

    let tags = getStyleSmall(content);
    let jmps = getStyleSmall(modules);

    if (header && footer) {
        header.parentNode.removeChild(header);
        footer.parentNode.insertBefore(header,footer);
        footer.setAttribute("style","margin-top: 0em");
    }

    // Reorganize properties section to be the metadata section.
    if (props) {
        let deets = document.createElement("details");
        let summy = document.createElement("summary");
        let title = document.createElement("h2");
        let hrule = document.createElement("hr");
        let bold = document.createElement("p");

        // TODO guard these expressions.
        title.appendChild(pkg);
        bold.setAttribute("style","font-weight: bold");
        bold.innerHTML = ttl.innerHTML;
        descr.insertBefore(bold,descr.children[0]);

        if (jmps) {
            while (jmps.childNodes.length > 1) {
                let child = jmps.childNodes[0]
                if (child.tagName != "A") {
                    child.textContent = " / ";
                }
                title.appendChild(child);
            }
            jmps.parentNode.removeChild(jmps);
        }
        title.setAttribute("style","display: inline");
        summy.appendChild(title);
        deets.appendChild(summy);
        if (tags) {
            tags.parentNode.removeChild(tags);
            deets.appendChild(tags);
        }
        while (props.childNodes.length > 0) {
            deets.appendChild(props.childNodes[0]);
        }
        if (maint) {
            maint.parentNode.removeChild(maint);
            deets.appendChild(maint);
        }
        deets.appendChild(hrule);
        props.setAttribute("style","padding-top: 1em");
        props.setAttribute("id","metadata");
        props.appendChild(deets);
    }

    if (descr) {
        props.parentNode.removeChild(props);
        descr.parentNode.insertBefore(props,descr);
    }

})()