S3 hosted website with Cloudflare returns 404 status code for any route

Turns out people just didn't host on S3 with Cloudflare before workers, and if they did, they didn't care/notice that their routes would return 404.

Anyway, this is the solution with Cloudflare workers to force the return code of 200:

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

async function fetchAndApply(request) {
  let originalResponse = await fetch(request)

  const contentType = originalResponse.headers.get("Content-Type")

  // Only bother with index pages (not assets)
  if (contentType && contentType.includes("text/html")) {

    // Force 404's from S3 to return as 200 to prevent Google indexing issues
    let response = new Response(originalResponse.body, {
        ...originalResponse,
        status: 200, 
        statusText: 'OK'
      }
    )

    // Don't cache index.html
    response.headers.set('Cache-Control', 'max-age=0')

    return response
  }

  return originalResponse
}

I beleive you can use this approach from the AWS docs. https://docs.aws.amazon.com/AmazonS3/latest/dev/how-to-page-redirect.html Example #3 at the bottom of the document page.

This is S3 bucket for the demo.

EDIT: removed the URL, it served the purpose that was usable only to author of the question.

Here is short example. Which will redirect to "home" if not found.

<RoutingRules>
<RoutingRule>
<Condition>
  <HttpErrorCodeReturnedEquals>404</HttpErrorCodeReturnedEquals >
</Condition>
<Redirect>
  <HostName>BUCKETNAME.s3-website-eu-west-1.amazonaws.com</HostName>
  <ReplaceKeyWith></ReplaceKeyWith>
</Redirect>
</RoutingRule>