User script for Violentmonkey / Tampermonkey / Greasemonkey to replace text

drumpf.js

// ==UserScript==(
// @name        Drumpf III
// @match       *://*/*
// @grant       none
// @run-at      document-end
// @version     2.0
// @description Makes you feel better by replacing 'Trump' with 'Drumpf' (asynchronously for no slowdown).
// ==/UserScript==

(() => {
    const CHUNK_SIZE = 50;
    const queue = [];
    let processing = false;
    const RE = /\bTrump\b/g;
    function replaceInNode(textNode) {
        // Skip editable fields (contentEditable without a value is also covered)
        if (textNode.parentNode && textNode.parentNode.isContentEditable) return;
        if (textNode.parentNode && textNode.parentNode.matches?.('textarea, input')) return;

        const txt = textNode.nodeValue;
        if (txt && RE.test(txt)) {
            textNode.nodeValue = txt.replace(RE, 'Drumpf');
        }
    }

    function processChunk() {
        if (queue.length === 0) {
            processing = false;
            return;
        }
        let i = 0;
        while (i < CHUNK_SIZE && queue.length) {
            const node = queue.shift();
            if (node && node.parentNode) replaceInNode(node);
            i++;
        }
        setTimeout(processChunk, 0); // yield to UI thread
    }

    function enqueue(node) {
        queue.push(node);
        if (!processing) {
            processing = true;
            processChunk();
        }
    }

    // Walk a subtree and enqueue all Text nodes
    function walkAndEnqueue(root) {
        // Do not descend into editable containers
        if (root.nodeType === Node.ELEMENT_NODE && root.isContentEditable) return;
        if (root.matches?.('textarea, input')) return;

        const walker = document.createTreeWalker(
            root,
            NodeFilter.SHOW_TEXT,
            null,
            false
        );
        let n;
        while ((n = walker.nextNode())) enqueue(n);
    }

    const observer = new MutationObserver(mutations => {
        for (const m of mutations) {
            // 4a) New nodes added somewhere in the tree
            if (m.type === 'childList') {
                for (const added of m.addedNodes) {
                    // If the added node itself is a Text node → enqueue directly
                    if (added.nodeType === Node.TEXT_NODE) {
                        enqueue(added);
                    } else {
                        // Normal DOM walk for the rest of the subtree
                        walkAndEnqueue(added);
                    }
                }
            }
        }
    });

    walkAndEnqueue(document.body);
    observer.observe(document.body, {
        childList: true,
        subtree: true
    });

})();