disable smooth-scroll for UserScript

anti-smooth-scroll.user.js

// ==UserScript==
// @name        anti smooth-scroll
// @namespace   http://noromanba.flavors.me
// @description disable smooth-scrolling for UserScript
// @include     http://example.com/DIY
// @grant       none
// @noframes
// @run-at      document-end
// @version     2018.2.25.1
// @homepage    https://gist.github.com/noromanba/07f3b4dafbb166692b3e777594edfead
// @downloadURL https://gist.github.com/noromanba/07f3b4dafbb166692b3e777594edfead/raw/anti-smooth-scroll.user.js
// @license     MIT License https://nrm.mit-license.org/2016
// @author      noromanba   https://noromanba.github.com
// @icon        https://upload.wikimedia.org/wikipedia/commons/thumb/d/d4/BSicon_uLSTRa.svg/256px-BSicon_uLSTRa.svg.png
// ==/UserScript==

// Icon (PD by Useddenim)
// https://commons.wikimedia.org/wiki/File%3ABSicon_uLSTRa.svg

// Devel
// https://gist.github.com/noromanba/07f3b4dafbb166692b3e777594edfead


// disable in Browser side smooth c.f.
// - Chrome family
//      chrome://flags/#smooth-scrolling
// - Firefox family
//  - https://support.mozilla.org/en-US/questions/1075336#answer-761949
//      about:preferences#advanced
//    - do search "smooth" in searchbox
//  - direct editing
//      about:config
//          general.smoothScroll | true -> false

// via
// http://stackoverflow.com/questions/29416448/how-to-disable-smooth-scrolling-in-ie11
(() => {
    'use strict';

    const roughen = (ctx) => {
        // TBD DOMMouseScroll event
        // TODO throttle/debounce
        ctx.addEventListener('mousewheel', evt => {
            //evt.preventDefault();
            //evt.stopImmediatePropagation();
            window.scrollTo(0, window.pageYOffset - evt.wheelDelta);
        }, {
            // Scroll Jank c.f.
            // https://blog.jxck.io/entries/2016-06-09/passive-event-listeners.html
            passive: true,
        });
    };
    roughen(document.body);

    // TBD handle other smoothed elements
})();