GitHub Code Show Whitespace

A userscript that shows whitespace (space, tabs and carriage returns) in code blocks

נכון ליום 02-09-2017. ראה הגרסה האחרונה.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name        GitHub Code Show Whitespace
// @version     0.1.7
// @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'>&nbsp;</span>",
			"%09"  : "<span class='pl-tab ghcw-whitespace'>\x09</span>",
			// non-matching key; applied manually
			"CRLF" : "<span class='pl-crlf ghcw-whitespace'></span>\n"
		},
		// ignore +/- in diff code blocks
		regexWS = /^(?:[+-]*)(\x20|&nbsp;|\x09)+/g,
		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 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;

			// loop with delay to allow user interaction
			const loop = () => {
				let el, line,
					// max number of DOM insertions per loop
					max = 0;
				while (max < 50 && indx < len) {
					if (indx >= len) {
						return;
					}
					line = lines[indx];
					el = line.firstChild;
					// first node is a syntax string and may have leading whitespace
					if (
						el &&
						el.nodeType === 1 &&
						el.classList.contains("pl-s") &&
						el.firstChild.nodeType === 3
					) {
						el.innerHTML = replaceWhitespace(el.innerHTML);
					}
					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();

})();