HideRedditCommentBox.user.js

// ==UserScript==
// @name         Hide Reddit Comment Box
// @description  Hides the Reddit comment box
// @version      1.0.6
// @author       heavyLobster2
// @namespace    github.com/heavyLobster2
// @downloadURL  https://gist.github.com/heavyLobster2/c7df692023ebab3729bc/raw/HideRedditCommentBox.user.js
// @include      *://*.reddit.com/r/*/comments/*
// @grant        none
// ==/UserScript==
(function () {
    "use strict";
    var style = document.createElement("style");
    style.type = "text/css";
    document.head.appendChild(style);
    style.sheet.insertRule("section.commentsignupbar { display: none !important; }");
    style.sheet.insertRule("div.commentarea > div.usertext { margin-bottom: 4px !important; }");
    
    var commentForm = document.querySelector("div.commentarea > form.usertext");
    if (commentForm) {
        var toggleLink = document.createElement("a");
        toggleLink.href = "#";
        
        var toggleDiv = document.createElement("div");
        toggleDiv.appendChild(toggleLink);
        
        var commentContainer = document.createElement("div");
        commentContainer.classList.add("usertext");
        commentContainer.appendChild(toggleDiv);
        
        commentForm.parentNode.replaceChild(commentContainer, commentForm);
        commentContainer.appendChild(commentForm);
        
        var showing = true;
        var toggle = function () {
            if (showing) {
                toggleLink.textContent = "Post a new comment";
                commentForm.style.display = "none";
                showing = false;
            } else {
                toggleLink.textContent = "Cancel new comment";
                commentForm.style.display = "";
                showing = true;
            }
            return false;
        };
        toggleLink.onclick = toggle;
        toggle();
    }
})();