Github Reply Comments

Easy reply to Github comments
As of 09. 12. 2019. See the latest version.
Visit the author's site for support, ask a question, post a review, or report the script.
Wrap lines
// ==UserScript==
// @name        Github Reply Comments
// @namespace   https://github.com/jerone/UserScripts
// @description Easy reply to Github comments
// @author      jerone
// @copyright   2016+, jerone (http://jeroenvanwarmerdam.nl)
// @license     CC-BY-NC-SA-4.0; https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode
// @license     GPL-3.0-or-later; http://www.gnu.org/licenses/gpl-3.0.txt
// @homepage    https://github.com/jerone/UserScripts/tree/master/Github_Reply_Comments
// @homepageURL https://github.com/jerone/UserScripts/tree/master/Github_Reply_Comments
// @supportURL  https://github.com/jerone/UserScripts/issues
// @contributionURL https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=VCYMHWQ7ZMBKW
// @version     1.0.4
// @icon        https://github.githubassets.com/pinned-octocat.svg
// @grant       none
// @include     https://github.com/*
// @include     https://gist.github.com/*
// @require     https://unpkg.com/[email protected]/dist/turndown.js
// @require     https://unpkg.com/[email protected]/dist/turndown-plugin-gfm.js
// @require     https://unpkg.com/[email protected]/turndown-plugin-github-code-snippet.js
// ==/UserScript==

(function () {

	String.format = function (string) {
		var args = Array.prototype.slice.call(arguments, 1, arguments.length);
		return string.replace(/{(\d+)}/g, function (match, number) {
			return typeof args[number] !== "undefined" ? args[number] : match;
		});
	};

	var turndownService = new TurndownService({ headingStyle: 'atx', codeBlockStyle: 'fenced', hr: '***' });
	turndownService.use(turndownPluginGfm.gfm);
	turndownService.use(turndownPluginGithubCodeSnippet);

	function getCommentTextarea(replyBtn) {
		var newComment = replyBtn;
		while (newComment && !newComment.classList.contains("js-quote-selection-container")) {
			newComment = newComment.parentNode;
		}

		var inlineComment = newComment.querySelector(".js-inline-comment-form-container");
		if (inlineComment) {
			inlineComment.classList.add("open");
		}

		var textareas = newComment.querySelectorAll(":scope > :not(.last-review-thread) .comment-form-textarea");
		return textareas[textareas.length - 1];
	}

	function getCommentMarkdown(comment) {
		var commentText = "";

		// Use raw comment when available.
		var commentForm = comment.querySelector(".comment-form-textarea");
		if (commentForm) {
			commentText = commentForm.value;
		}

		// Convert comment HTML to markdown.
		if (!commentText) {
			// Clone it, so we can alter the HTML a bit, without modifing the page.
			var commentBody = comment.querySelector(".comment-body").cloneNode(true);

			// Remove 'Toggle code wrap' buttons from https://greasyfork.org/en/scripts/18789-github-toggle-code-wrap
			Array.prototype.forEach.call(commentBody.querySelectorAll(".ghd-wrap-toggle"), function (ghd) {
				ghd.remove();
			});

			// GitHub add an extra new line, which is converted by Turndown.
			Array.prototype.forEach.call(commentBody.querySelectorAll("pre code"), function (pre) {
				pre.innerHTML = pre.innerHTML.replace(/\n$/g, '');
			});

			commentText = turndownService.turndown(commentBody.innerHTML);
		}

		return commentText;
	}

	function addReplyButtons() {
		Array.prototype.forEach.call(document.querySelectorAll(".comment, .review-comment"), function (comment) {
			var oldReply = comment.querySelector(".GithubReplyComments, .GithubCommentEnhancerReply");
			if (oldReply) {
				oldReply.parentNode.removeChild(oldReply);
			}

			var header = comment.querySelector(":scope > :not(.minimized-comment) .timeline-comment-header"),
				actions = comment.querySelector(":scope > :not(.minimized-comment) .timeline-comment-actions");

			if (!header) {
				header = actions;
			}

			if (!actions) {
				if (!header) {
					return;
				}
				actions = document.createElement("div");
				actions.classList.add("timeline-comment-actions");
				header.insertBefore(actions, header.firstElementChild);
			}

			var reply = document.createElement("button");
			reply.setAttribute("type", "button");
			reply.setAttribute("title", "Reply to this comment");
			reply.setAttribute("aria-label", "Reply to this comment");
			reply.classList.add("GithubReplyComments", "btn-link", "timeline-comment-action", "tooltipped", "tooltipped-ne");
			reply.addEventListener("click", function (e) {
				e.preventDefault();

				var timestamp = comment.querySelector(".js-timestamp, .timestamp");

				var commentText = getCommentMarkdown(comment);
				commentText = commentText.trim().split("\n").map(function (line) {
					return "> " + line;
				}).join("\n");

				var newComment = getCommentTextarea(this);

                var author = comment.querySelector(".author");
                var authorLink = location.origin + (author.getAttribute("href") || "/" + author.textContent);

				var text = newComment.value.length > 0 ? "\n" : "";
				text += String.format('[**@{0}**]({1}) commented on [{2}]({3} "{4} - Replied by Github Reply Comments"):\n{5}\n\n',
					author.textContent,
					authorLink,
					timestamp.firstElementChild.getAttribute("title"),
					timestamp.href,
					timestamp.firstElementChild.getAttribute("datetime"),
					commentText);

				newComment.value += text;
				newComment.setSelectionRange(newComment.value.length, newComment.value.length);
				newComment.focus();
			});

			var svg = document.createElementNS("http://www.w3.org/2000/svg", "svg");
			svg.classList.add("octicon", "octicon-mail-reply");
			svg.setAttribute("height", "16");
			svg.setAttribute("width", "16");
			reply.appendChild(svg);
			var path = document.createElementNS("http://www.w3.org/2000/svg", "path");
			path.setAttribute("d", "M6 2.5l-6 4.5 6 4.5v-3c1.73 0 5.14 0.95 6 4.38 0-4.55-3.06-7.05-6-7.38v-3z");
			svg.appendChild(path);

			actions.appendChild(reply);
		});
	}

	// init;
	addReplyButtons();

	// on pjax;
	document.addEventListener('pjax:end', addReplyButtons);

})();