UserScript that allows you to toggle ads on OfferUp

toggleAdsOfferUp.js

// ==UserScript==
// @name         OfferUp Toggle Ads
// @namespace    https://offerup.com/
// @version      0.1
// @description  Allows you to toggle ads on OfferUp
// @author       ackerleytng
// @match        https://offerup.com/search/*
// @grant        GM_addStyle
// ==/UserScript==

(function() {
    'use strict';

    var shouldShowAds = false;

    const toggleAdState = function() {
        shouldShowAds = !shouldShowAds;
    }

    const applyAdState = function () {
        for (const e of document.querySelectorAll('a[data-impression-feedback-url]')) {
            if (shouldShowAds) {
                e.style.display = 'block';
            } else {
                e.style.display = 'none';
            }
        }
    }

    const toggleAndApply = function () {
        toggleAdState();
        applyAdState();
    }

    const addButton = function() {
        const d = document.createElement('div');
        d.innerHTML = '<button id="myButton" type="button">Toggle Ads</button>';
        d.setAttribute ('id', 'myContainer');
        document.body.appendChild(d);

        document.getElementById("myButton").addEventListener("click", toggleAndApply, false);

        GM_addStyle ( `
    #myContainer {
        position:               fixed;
        top:                    0;
        left:                   0;
        font-size:              20px;
        background:             orange;
        border:                 3px solid black;
        margin:                 5px;
        opacity:                0.9;
        z-index:                1100;
        padding:                5px;
    }
    #myButton {
        margin: 0;
        padding: 5px;
    }
` );
    }

    addButton();
    applyAdState();
    // So that on scrolling, new ads will either be shown or hidden
    window.addEventListener('load', applyAdState, false);
})();