who-did-this.js

const wrappedNodes = new Set<Class<LexicalNode>>();

function registerWhoDidThisListener<T: LexicalNode>(
  klass: Class<T>,
  callback: T => void,
): () => void {
  const {prototype} = klass;
  const {
    constructor: {name},
    // $FlowExpectedError[method-unbinding]
    getWritable,
  } = prototype;

  if (wrappedNodes.has(klass)) {
    throw err(`${name} is already wrapped with registerWhoDidThisListener`);
  }

  wrappedNodes.add(klass);

  // $FlowExpectedError[missing-this-annot]
  // $FlowExpectedError[cannot-write]
  prototype.getWritable = function () {
    // We override prototype method, so it's all good
    // eslint-disable-next-line fb-www/avoid-this-outside-classes
    callback(this);
    // We override prototype method, so it's all good
    // eslint-disable-next-line fb-www/avoid-this-outside-classes
    return getWritable.apply(this, arguments);
  };

  return () => {
    // $FlowExpectedError[cannot-write]
    prototype.getWritable = getWritable;
    wrappedNodes.delete(klass);
  };
}

component MLCWhoDidThisPlugin() {
  const [editor] = useLexicalComposerContext();

  useEffect(() => {
    return registerWhoDidThisListener(MyNodeClass, node => {
      console.log(node);
      debugger;
    });
  }, [editor]);

  return null;
}