google-translate-simulator.js

function translate() {
  const walker = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT);

  /** @type Node[] */
  const textNodes = [];

  /** @type Node */
  let currentNode;

  while ((currentNode = walker.nextNode())) {
    textNodes.push(currentNode);
  }

  for (const node of textNodes) {
    const text = node.textContent;
    
    // Replace text node so that react will hold stale reference
    const parent = node.parentElement;
    parent.removeChild(node);
    
    // Instead of actually translating, just uppercase the text
    parent.appendChild(document.createTextNode(text.toUpperCase()));
  }

  return textNodes;
}