GitLab Code Show Whitespace

A userscript that shows whitespace (space, tabs and carriage returns) in code blocks based on https://github.com/Mottie/GitHub-userscripts/wiki/GitHub-code-show-whitespace (without mutations)

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        GitLab Code Show Whitespace
// @version     1.1.10-a
// @description A userscript that shows whitespace (space, tabs and carriage returns) in code blocks based on https://github.com/Mottie/GitHub-userscripts/wiki/GitHub-code-show-whitespace (without mutations)
// @license     MIT
// @author      Nikolai Merinov
// @namespace   https://github.com/mnd
// @include     https://gitlab.*
// @run-at      document-idle
// @grant       GM.addStyle
// @grant       GM_addStyle
// @require     https://greasemonkey.github.io/gm4-polyfill/gm4-polyfill.js?updated=20180103
// @icon        https://assets-cdn.github.com/pinned-octocat.svg
// ==/UserScript==
(() => {
    "use strict";

    // 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'>&nbsp;</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>"
    },
	  span = document.createElement("span"),
	  // ignore +/- in diff code blocks
	  regexWS = /(\x20|&nbsp;|\x09)/g,
	  regexCR = /\r*\n$/,
	  regexExceptions = /(\.md)$/i,

	  toggleButton = document.createElement("div");
    toggleButton.className = "ghcw-toggle btn has-tooltip btn-file-option";
    toggleButton.setAttribute("aria-label", "Toggle Whitespace");
    toggleButton.innerHTML = "<span class='pl-tab'></span>";

    GM.addStyle(`
		.ghcw-active .ghcw-whitespace,
		.gist-content-wrapper .file-actions .btn-group {
			position: relative;
			display: inline;
		}
		.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";
			top: .1em;
		}
		.ghcw-active .pl-crlf:before {
			content: "\\231d";
		}
		/* 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 */
		.text-file td.line .pl-space:first-child {
			opacity: 0;
		}
	`);

    
    function $(selector, el) {
	return (el || document).querySelector(selector);
    }

    function $$(selector, el) {
	return [...(el || document).querySelectorAll(selector)];
    }

    function addToggle() {
	$$(".file-actions").forEach(el => {
	    if (!$(".ghcw-toggle", el)) {
		el.insertBefore(toggleButton.cloneNode(true), el.childNodes[0]);
	    }
	});
    }

    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 => ({
	    "<": "&lt;",
	    ">": "&gt;",
	    "&": "&amp;",
	    "'": "&#39;",
	    "\"": "&quot;"
	}[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 addWhitespace(block) {
	let lines, indx, len;
	if (block && !block.classList.contains("ghcw-processed")) {
	    block.classList.add("ghcw-processed");
	    indx = 0;

	    // class name of each code row
	    lines = $$(".line", block);
	    len = lines.length;

	    // loop with delay to allow user interaction
	    const loop = () => {
		let line, nodes,
		    // 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
		    nodes = getNodes(line);
		    replaceTextNode(nodes);
		    // remove end CRLF if it exists; then add a line ending
		    line.innerHTML = line.innerHTML.replace(regexCR, "") + whitespace.CRLF;
		    max++;
		    indx++;
		}
		if (indx < len) {
		    setTimeout(() => {
			loop();
		    }, 100);
		}
	    };
	    loop();
	}
    }

    function detectDiff(wrap) {
	const header = $(".btn-clipboard", wrap);
	if ($(".diff-content", wrap) && header) {
	    const file = header.getAttribute("data-clipboard-text");
	    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");
	    }
	}
    }

    // bind whitespace toggle button
    document.addEventListener("click", event => {
	const target = event.target;
	if (
	    target.nodeName === "DIV" &&
		target.classList.contains("ghcw-toggle")
	) {
	    const wrap = target.closest(".diff-file");
	    const block = $(".text-file", wrap); // diff-content
	    if (block) {
		target.classList.toggle("selected");
		block.classList.toggle("ghcw-active");
		detectDiff(wrap);
		addWhitespace(block);
	    }
	}
    });

    // Add toggle every second to be sure that it will start after each update
    setInterval(addToggle, 1000);
    // toggle added to diff & file view
    addToggle();
})();