301-redirect

/**
 * IMPORTANT NOTE: 
 * When you try to run 301/302 redirects using Workers, the preview
 * browser on the right of this script will throw an error. Disregard it!
 * 
 * The script will function properly. The reason the preview browser runs
 * into this problem is that it's actually trying to redirect you, but
 * the Cloudflare dashboard is ensuring that you stay on the page to finish
 * your code
 * 
 * DOCUMENTATION:
 * https://developer.mozilla.org/en-US/docs/Web/API/Request/Request
 * https://developer.mozilla.org/en-US/docs/Web/API/Response/Response
 */

addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request))
})

async function handleRequest(request) {
  // We can separate the different components of a URL string like this:
  const incomingURI = new URL(request.url)
  const hostName = incomingURI.host
  const pathName = incomingURI.pathname
  const protocol = incomingURI.protocol
  const queryParams = incomingURI.search

  console.log(`${protocol}//${hostName}${pathName}?${queryParams}`)

  // Declate the "response" variable
  let response

  // Evaluate each "case" for a "true" response. If a true response is found,
  // assign a value to the response variable, "break" the switch condition
  // and return the response.
  // If none of these conditions match, execute the original request
  switch (true) {
    case queryParams.includes('author=bob'):
      response = Response.redirect('https://google.com', 301)
      break

    case hostName.includes('123.example.com'):
      response = Response.redirect('https://www.example.com', 301)
      break

    case pathName.includes('/path/bill'):
      response = Response.redirect('https://www.example.com/bob', 301)
      break

    default:
      return fetch(request)
  }
  
  return response
}