Reddit Code-ifier Script

codeifier.js

// ==UserScript==
// @name         Reddit Code-ifier
// @namespace    https://*.reddit.com/*
// @version      1.0
// @description  Fix up messy code formatting on Reddit.
// @author       u/thebermudalocket
// @match        https://*.reddit.com/*
// @grant        none
// @run-at       document-end
// ==/UserScript==

(function() {
    'use strict';

    $(".comment, .usertext").each(function() {
        var linesOfCode = new Array();

        let codeTags = $(this).find("code");
        let firstCodeTag = codeTags.first();
        let firstDepth = firstCodeTag.parents().length;
        codeTags.each(function() {
            if ($(this).parents().length != firstDepth) {
                return;
            }
            var line = $(this).html();
            if (line.length > 100) {
                return;
            }
            linesOfCode.push(line);
        });
        if (linesOfCode.length <= 1) {
            return;
        }

        codeTags.each(function() {
            $(this).hide();
            $(this).next("br").hide(); // hide <br>s
        });

        var numberOfOpenSquareBrackets = 0;
        var nestedLevel = 0;
        for (var i = 0; i < linesOfCode.length; i++) {
            let thisLine = linesOfCode[i];
            let thisLineStartsWithCurlyBrace = thisLine[0] === "}";
            if (thisLineStartsWithCurlyBrace) {
                nestedLevel--;
            }
            let thisLineEndsWithCurlyBrace = thisLine[thisLine.length - 1] === "{";

            linesOfCode[i] = ' '.repeat(4 * (nestedLevel + numberOfOpenSquareBrackets)) + thisLine;

            if (thisLineEndsWithCurlyBrace) {
                nestedLevel++;
            }

            for (var j = 0; j < thisLine.length - 1; j++) {
                let char = thisLine[j];
                if (char === "[") {
                    numberOfOpenSquareBrackets++;
                } else if (char === "]") {
                    numberOfOpenSquareBrackets--;
                }
            }

        }

        firstCodeTag.before("<pre><code style='overflow-x: scroll'>" + linesOfCode.join("\n") + "</code></pre>");
    });
})();