A userscript that shows whitespace (space, tabs and carriage returns) in code blocks
// ==UserScript==
// @name GitHub Code Show Whitespace
// @version 0.1.8
// @description A userscript that shows whitespace (space, tabs and carriage returns) in code blocks
// @license MIT
// @author Rob Garrison
// @namespace https://github.com/Mottie
// @include https://github.com/*
// @include https://gist.github.com/*
// @run-at document-idle
// @grant GM_addStyle
// @require https://greasyfork.org/scripts/28721-mutations/code/mutations.js?version=189706
// @icon https://github.com/fluidicon.png
// ==/UserScript==
(() => {
"use strict";
// include em-space & en-space?
const whitespace = {
"%20" : "<span class='pl-space ghcw-whitespace'> </span>",
"%A0" : "<span class='pl-nbsp ghcw-whitespace'> </span>",
"%09" : "<span class='pl-tab ghcw-whitespace'>\x09</span>",
// non-matching key; applied manually
"CRLF" : "<span class='pl-crlf ghcw-whitespace'></span>\n"
},
span = document.createElement("span"),
// ignore +/- in diff code blocks
regexWS = /^(?:[+-]*)(\x20| |\x09)+|(\x20| |\x09)+$/g,
regexTrailingWS = /(\x20| |\x09)+$/,
regexCR = /\r*\n$/,
regexTabSize = /\btab-size-\d\b/g,
toggleButton = document.createElement("div");
toggleButton.className = "ghcw-toggle btn btn-sm tooltipped tooltipped-n";
toggleButton.setAttribute("aria-label", "Toggle Whitespace");
toggleButton.innerHTML = "<span class='pl-tab'></span>";
GM_addStyle(`
.highlight .blob-code-inner { tab-size: 2; }
/* GitHub-Dark overrides the above setting */
.highlight.ghcw-active.tab-size-2 .pl-tab { width: 1.1em; }
.highlight.ghcw-active.tab-size-4 .pl-tab { width: 2.2em; }
.highlight.ghcw-active.tab-size-6 .pl-tab { width: 3.3em; }
.highlight.ghcw-active.tab-size-8 .pl-tab { width: 4.4em; }
.ghcw-active .ghcw-whitespace,
.gist-content-wrapper .file-actions .btn-group {
position: relative;
display: inline-block;
}
.ghcw-active .ghcw-whitespace:before {
position: absolute;
overflow: hidden;
opacity: .4;
user-select: none;
}
.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: -.75em;
}
`);
function addToggle() {
$$(".file-actions").forEach(el => {
if (!$(".ghcw-toggle", el)) {
el.insertBefore(toggleButton.cloneNode(true), el.childNodes[0]);
}
});
}
function replaceWhitespace(html) {
return html
.replace(regexWS, s => {
let idx = 0,
ln = s.length,
result = "";
for (idx = 0; idx < ln; idx++) {
result += whitespace[encodeURI(s[idx])] || s[idx] || "";
}
return result;
});
}
function replaceTextNode(el) {
let indx = el.textContent.search(regexTrailingWS);
if (indx > -1) {
let node = el.splitText(indx);
const elm = span.cloneNode();
elm.innerHTML = replaceWhitespace(
node.textContent.replace(regexCR, "")
);
node.parentNode.insertBefore(elm, node);
node.parentNode.removeChild(node);
}
}
function addWhitespace(block) {
let lines, indx, len;
if (block && !block.classList.contains("ghcw-processed")) {
block.classList.add("ghcw-processed");
updateTabSize(block);
indx = 0;
// class name of each code row
lines = $$(".blob-code-inner:not(.blob-code-hunk)", block);
len = lines.length;
const checkNode = el => {
if (el) {
if (el.nodeType === 3 && el.textContent) {
replaceTextNode(el);
} else if (
el.nodeType === 1 &&
el.matches(".pl-s, .pl-s1, .pl-c") &&
el.firstChild &&
el.firstChild.nodeType === 3
) {
el.innerHTML = replaceWhitespace(el.innerHTML);
}
}
};
// loop with delay to allow user interaction
const loop = () => {
let line,
// max number of DOM insertions per loop
max = 0;
while (max < 50 && indx < len) {
if (indx >= len) {
return;
}
line = lines[indx];
// first node is a syntax string and may have leading whitespace
checkNode(line.firstChild);
checkNode(line.lastChild);
// trailing whitespace inside a comment text node
if (line.lastChild.children) {
checkNode(line.lastChild.lastChild);
}
line.innerHTML = replaceWhitespace(line.innerHTML)
// remove end CRLF if it exists
.replace(regexCR, "") + whitespace.CRLF;
max++;
indx++;
}
if (indx < len) {
setTimeout(() => {
loop();
}, 100);
}
};
loop();
}
}
function updateTabSize(block) {
// remove previous tab-size setting
block.className = block.className.replace(regexTabSize, " ");
// calculate tab-size; GitHub-Dark allows user modification
const len = window.getComputedStyle($(".blob-code-inner", block)).tabSize;
block.classList.add(`tab-size-${len}`);
}
function $(selector, el) {
return (el || document).querySelector(selector);
}
function $$(selector, el) {
return Array.from((el || document).querySelectorAll(selector));
}
function closest(selector, el) {
while (el && el.nodeType === 1) {
if (el.matches(selector)) {
return el;
}
el = el.parentNode;
}
return null;
}
// bind whitespace toggle button
document.addEventListener("click", event => {
const target = event.target;
if (
target.nodeName === "DIV" &&
target.classList.contains("ghcw-toggle")
) {
let block = $(".highlight", closest(".file", target));
if (block) {
target.classList.toggle("selected");
block.classList.toggle("ghcw-active");
updateTabSize(block);
addWhitespace(block);
}
}
});
document.addEventListener("ghmo:container", addToggle);
document.addEventListener("ghmo:diff", addToggle);
// toggle added to diff & file view
addToggle();
})();