console.log(val1)
console.log(val1, /* …, */ valN)

function handleEvent(event) {
  const { request } = event;
  const url = new URL(request.url);

  // Output basic information
  console.log('Process request:', url.pathname);

  // Output prompt message
  console.info('Request processing started');

  // Output attention information
  console.notice('Request processing method:', request.method);

  // Output warning information
  console.warn('Request parameters may be incomplete');

  // Output error information
  console.error('Error occurred while processing the request');

  return event.respondWith(new Response('Hello World'));
}

addEventListener('fetch', event => {
  handleEvent(event);
});