TamperMonkey add to playlist

add_to_playlist.js

// ==UserScript==
// @name         YouTube add to playlist
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @include      https://www.youtube.com/*
// @grant        none
// ==/UserScript==

let playlistButton = null;
let playlistName = null;
playlistName = "2017";

function onKeyPress(e) {
    // match ']' key
    if (e.keyCode === 93){
        clickAdd();
    }

    // match '\' key
    if (e.keyCode === 92){
        playlistButton = findPlaylistButton(playlistName);
        playlistButton.click();
    }

}

function clickAdd(){
    let addButton;

    let col = document.getElementsByClassName("yt-uix-button-content")
    for (let i = 0; i < col.length; i++){
        if(col.item(i).innerText === "Add to"){
            addButton = col.item(i);
        }
    }

    addButton.click();
}

function findPlaylistButton(playlistName){
    let classSearch = "addto-playlist-item yt-uix-button-menu-item contains-all-selected-videos";
    classSearch = "playlist-name";

    //console.log("scanning for playlist-status elements...");
    let collection = document.getElementsByClassName(classSearch);
    //console.log("found " + playlistElem.length);

    for (let i = 0; i < collection.length; i++){
        if(collection.item(i).innerText === playlistName){
            //console.log("item found!");
            return collection.item(i);
        }
    }

    //console.log("finished scanning. no matches found");
    return null;
}

(function() {
    'use strict';
    document.onkeypress = onKeyPress;

    console.log("EDM_youtube");
    findPlaylistButton();
})();


/*
<button class="playlist-status" role="menuitemcheckbox" title="Click to remove video from 2017" aria-label="Click to remove video from 2017 Public playlist" aria-checked="checked"></button>
*/