[Bug]: Example given in "Handling return values in forms" section for "use-server" docs fails to compile #7167

// requestUsername.js
'use server';

export default async function requestUsername(formData) {
  const username = formData.get('username');
  // ..
}

// UsernameForm.js
'use client';

import { useActionState } from 'react';
import requestUsername from './requestUsername';

function UsernameForm() {
  const [state, action] = useActionState(requestUsername, null, 'n/a');
  // ..
}

async function increment(previousState, formData) {
  return previousState + 1;
}

function StatefulForm({}) {
  const [state, formAction] = useActionState(increment, 0);
  // ..
}