Manga Plus Auto Sort

MangaPlusAutoSort.user.js

// ==UserScript==
// @name         Manga Plus Auto Sort
// @namespace    https://shotasenga.com/
// @version      1.0.1
// @description  Automatically sorts chapter list in descending order on Manga Plus
// @author       shotasenga
// @match        https://mangaplus.shueisha.co.jp/titles/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    
    let lastUrl = location.href;
    
    function sortChapters() {
        const sortIcon = document.querySelector('.ChapterList-module_sortIcon_1dGE4');
        
        if (sortIcon && sortIcon.tagName === 'IMG') {
            // Check if it's in ascending order by checking the src attribute
            if (sortIcon.src && sortIcon.src.startsWith('data:image/png;base64,iVBOR')) {
                sortIcon.click();
            }
        }
    }
    
    // Initial sort on page load
    function initialize() {
        setTimeout(sortChapters, 100);
    }
    
    // Watch for URL changes (SPA navigation)
    function checkForUrlChange() {
        if (location.href !== lastUrl) {
            lastUrl = location.href;
            // URL changed, wait for new content to load then sort
            setTimeout(sortChapters, 500);
        }
    }
    
    // Watch for DOM changes
    const observer = new MutationObserver(function(mutations) {
        let shouldCheck = false;
        
        mutations.forEach(function(mutation) {
            // Check if chapter list or sort icon was added/modified
            if (mutation.type === 'childList') {
                mutation.addedNodes.forEach(function(node) {
                    if (node.nodeType === 1) { // Element node
                        if (node.classList && node.classList.contains('ChapterList-module_sortIcon_1dGE4') ||
                            node.querySelector && node.querySelector('.ChapterList-module_sortIcon_1dGE4')) {
                            shouldCheck = true;
                        }
                    }
                });
            }
        });
        
        if (shouldCheck) {
            setTimeout(sortChapters, 100);
        }
    });
    
    // Start observing
    observer.observe(document.body, {
        childList: true,
        subtree: true
    });
    
    // Check for URL changes periodically
    setInterval(checkForUrlChange, 1000);
    
    // Initial load
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', initialize);
    } else {
        initialize();
    }
})();

Click this link to install the script. (Tampermonkey or similar is required)