A userscript that shows whitespace (space, tabs and carriage returns) in code blocks
// ==UserScript==
// @name GitHub Code Show Whitespace
// @version 1.2.13
// @description A userscript that shows whitespace (space, tabs and carriage returns) in code blocks
// @license MIT
// @author Rob Garrison
// @namespace https://github.com/Mottie
// @match https://github.com/*
// @match https://gist.github.com/*
// @run-at document-idle
// @grant GM_registerMenuCommand
// @grant GM.registerMenuCommand
// @grant GM.addStyle
// @grant GM_addStyle
// @grant GM.getValue
// @grant GM_getValue
// @grant GM.setValue
// @grant GM_setValue
// @require https://greasemonkey.github.io/gm4-polyfill/gm4-polyfill.js?updated=20180103
// @require https://greasyfork.org/scripts/28721-mutations/code/mutations.js?version=1108163
// @icon https://github.githubassets.com/pinned-octocat.svg
// @supportURL https://github.com/Mottie/GitHub-userscripts/issues
// ==/UserScript==
/* global GM */
(async () => {
"use strict";
let showWhiteSpace = await GM.getValue("show-whitespace", "false");
// include em-space & en-space?
const whitespace = {
// Applies \xb7 (·) to every space
"%20" : "<span class='pl-space ghcw-whitespace'> </span>",
// Applies \xb7 (·) to every non-breaking space (alternative: \u2423 (␣))
"%A0" : "<span class='pl-nbsp ghcw-whitespace'> </span>",
// Applies \xbb (») to every tab
"%09" : "<span class='pl-tab ghcw-whitespace'>\x09</span>",
// non-matching key; applied manually
// Applies \u231d (⌝) to the end of every line
// (alternatives: \u21b5 (↵) or \u2938 (⤸))
"CRLF" : "<span class='pl-crlf ghcw-whitespace'></span>\n"
};
const span = document.createElement("span");
// ignore +/- in diff code blocks
const regexWS = /(\x20| |\x09)/g;
const regexCR = /\r*\n$/;
const regexExceptions = /(\.md)$/i;
const toggleButton = document.createElement("div");
toggleButton.className = "ghcw-toggle btn btn-sm tooltipped tooltipped-s";
toggleButton.setAttribute("aria-label", "Toggle Whitespace");
toggleButton.innerHTML = "<span class='pl-tab'></span>";
GM.addStyle(`
div.file-actions > div,
.ghcw-active .ghcw-whitespace,
.gist-content-wrapper .file-actions .btnGroup {
position: relative;
display: inline;
}
.gist-content-wrapper .ghcw-toggle {
padding: 5px 10px; /* gist only */
}
.ghcw-toggle + .BtnGroup {
margin-left: 4px;
}
.ghcw-active .ghcw-whitespace:before {
position: absolute;
opacity: .5;
user-select: none;
font-weight: bold;
color: #777 !important;
top: -.25em;
left: 0;
}
.ghcw-toggle .pl-tab {
pointer-events: none;
}
.ghcw-active .pl-space:before {
content: "\\b7";
}
.ghcw-active .pl-nbsp:before {
content: "\\b7";
}
.ghcw-active .pl-tab:before,
.ghcw-toggle .pl-tab:before {
content: "\\bb";
}
.ghcw-active .pl-crlf:before {
content: "\\231d";
top: .1em;
}
/* weird tweak for diff markdown files - see #27 */
.ghcw-adjust .ghcw-active .ghcw-whitespace:before {
left: .6em;
}
/* hide extra leading space added to diffs - see #27 */
.diff-table tr.blob-expanded td > span:first-child .pl-space:first-child {
visibility: hidden;
}
.blob-code-inner > br {
display: none !important;
}
`);
function addFileActions() {
// file-actions removed from repo file view;
// still used in gists & file diffs
if (!$(".file-actions")) {
const rawBtn = $("#raw-url");
if (rawBtn) {
const group = rawBtn.closest(".BtnGroup");
const fileActionWrap = group && group.parentNode;
if (fileActionWrap) {
fileActionWrap.classList.add("file-actions");
}
}
}
}
function addToggle() {
addFileActions();
$$(".file-actions").forEach(el => {
// Don't add a toggle for new gists (editor showing)
if (!$(".ghcw-toggle", el) && !$("#indent-mode", el)) {
const dropdown = $(".dropdown", el);
// (* + sibling) Indicates where the whitespace toggle is added
// PR Layout: div.file-actions > div.flex-items-stretch > (details.dropdown + *)
// Repo file: div.file-actions > (* + div.BtnGroup) > a#raw-url
// Gist: div.file-actions > (* + a)
if (dropdown) {
el = dropdown.parentNode; // Fixes #91
}
el.insertBefore(toggleButton.cloneNode(true), el.childNodes[0]);
}
if (showWhiteSpace === "true") {
// Let the page render a bit before going nuts
setTimeout(show(el, true), 200);
}
});
}
function getNodes(line) {
const nodeIterator = document.createNodeIterator(
line,
NodeFilter.SHOW_TEXT,
() => NodeFilter.FILTER_ACCEPT
);
let currentNode,
nodes = [];
while ((currentNode = nodeIterator.nextNode())) {
nodes.push(currentNode);
}
return nodes;
}
function escapeHTML(html) {
return html.replace(/[<>"'&]/g, m => ({
"<": "<",
">": ">",
"&": "&",
"'": "'",
"\"": """
}[m]));
}
function replaceWhitespace(html) {
return escapeHTML(html).replace(regexWS, s => {
let idx = 0,
ln = s.length,
result = "";
for (idx = 0; idx < ln; idx++) {
result += whitespace[encodeURI(s[idx])] || s[idx] || "";
}
return result;
});
}
function replaceTextNode(nodes) {
let node, indx, el,
ln = nodes.length;
for (indx = 0; indx < ln; indx++) {
node = nodes[indx];
if (
node &&
node.nodeType === 3 &&
node.textContent &&
node.textContent.search(regexWS) > -1
) {
el = span.cloneNode();
el.innerHTML = replaceWhitespace(node.textContent.replace(regexCR, ""));
node.parentNode.insertBefore(el, node);
node.parentNode.removeChild(node);
}
}
}
function* modifyLine(lines) {
while (lines.length) {
const line = lines.shift();
// first node is a syntax string and may have leading whitespace
replaceTextNode(getNodes(line));
// remove end CRLF if it exists; then add a line ending
const html = line.innerHTML;
const update = html.replace(regexCR, "") + whitespace.CRLF;
if (update !== html) {
line.innerHTML = update;
}
}
yield lines;
}
function addWhitespace(block) {
if (block && !block.classList.contains("ghcw-processed")) {
block.classList.add("ghcw-processed");
let status;
// class name of each code row
const lines = $$(".blob-code-inner:not(.blob-code-hunk)", block);
const iter = modifyLine(lines);
// loop with delay to allow user interaction
const loop = () => {
for (let i = 0; i < 40; i++) {
status = iter.next();
}
if (!status.done) {
requestAnimationFrame(loop);
}
};
loop();
}
}
function detectDiff(wrap) {
const header = $(".file-header", wrap);
if ($(".diff-table", wrap) && header) {
const file = header.getAttribute("data-path");
if (
// File Exceptions that need tweaking (e.g. ".md")
regexExceptions.test(file) ||
// files with no extension (e.g. LICENSE)
file.indexOf(".") === -1
) {
// This class is added to adjust the position of the whitespace
// markers for specific files; See issue #27
wrap.classList.add("ghcw-adjust");
}
}
}
function showAll() {
$$(".blob-wrapper .highlight, .file .highlight").forEach(target => {
show(target, true);
});
}
function show(target, state) {
const wrap = target.closest(".file, .Box");
const block = $(".highlight", wrap);
if (block) {
wrap.querySelector(".ghcw-toggle").classList.toggle("selected", state);
block.classList.toggle("ghcw-active", state);
detectDiff(wrap);
addWhitespace(block);
}
}
function $(selector, el) {
return (el || document).querySelector(selector);
}
function $$(selector, el) {
return [...(el || document).querySelectorAll(selector)];
}
// bind whitespace toggle button
document.addEventListener("click", event => {
const target = event.target;
if (
target.nodeName === "DIV" &&
target.classList.contains("ghcw-toggle")
) {
show(target);
}
});
GM.registerMenuCommand("Set GitHub Code White Space", async () => {
let val = prompt("Always show on page load (true/false)?", showWhiteSpace);
if (val !== null) {
val = (val || "").toLowerCase();
await GM.setValue("show-whitespace", val);
showWhiteSpace = val;
showAll();
}
});
document.addEventListener("ghmo:container", addToggle);
document.addEventListener("ghmo:diff", addToggle);
// toggle added to diff & file view
addToggle();
})();