DeepL - Auto VN Translation Extension Helper (Fixed)

// ==UserScript==
// @name         DeepL - Auto VN Translation Extension Helper
// @version      1.1
// @grant        GM.setClipboard
// @match        https://www.deepl.com/translator
// @description  Watch for target language element class change, copy new value of textarea to clipboard each time change has been detected.
// @author       Zero_G
// @icon         https://www.deepl.com/img/logo/deepl-logo-blue.svg
// ==/UserScript==
(function() {
    'use strict';
    // Filters to apply to translated text
    const filters = {
      '' : /\"+|\'\'+/g,        // Remove " or ''
      '...' : /\.\.\.\.+/g      // Change multiple dots (when there are more than 3 to '...' only)
    }

    const mutationObserver = new MutationObserver(callback)

    // Observe the text div that contains the translation
    // But as the translated text appears in a <p> in a ::before css we need to watch
    // for added nodes
    mutationObserver.observe(
        document.getElementsByClassName('lmt__target_textarea')[0].lastChild, {
            childList: true
        }
    )

    function callback(mutationsList) {
        mutationsList.forEach(mutation => {
            if (mutation.type === 'childList' && // Irrelevant as we are already watching for childList only but meh
                mutation.addedNodes.length !== 0 && // Looking for a mutation with an added node
                mutation.removedNodes.length !== 0 && // This condition is to prevent a repeat
                !mutation.addedNodes[0].innerHTML.includes('<br')) { // Filter out garbage while translating
                // Get text from <p>
                let text = mutation.addedNodes[0].innerHTML;

                // Apply filters
                for (const [key, value] of Object.entries(filters)) {
                  text = text.replace(value, key);
                }

                // Copy to memory with GreaseMonkey special function (needs @grant)
                GM.setClipboard(text);
            }
        })
    }
})();