Route handler for blog.kubosho.com in CloudFront Functions

route_handler.js

function hasExtension(uri) {
  return uri.includes('.');
}

function isLastCharacterSlash(uri) {
  return uri.endsWith('/');
}

function isFeedLink(uri) {
  return uri.endsWith('/feed');
}

function isOldEntryUri(uri) {
  return uri.match(/entry/);
}

function handler(event) {
  var request = event.request;
  var originalUri = request.uri;
  var newUri = originalUri;

  if (isOldEntryUri(originalUri)) {
    newUri = originalUri.replace(/entry/, 'entries');

    return {
      statusCode: 308,
      statusDescription: 'Permanent Redirect',
      headers: { location: { value: newUri } },
    };
  }

  if (isLastCharacterSlash(originalUri)) {
    newUri = originalUri + 'index.html';
  } else if (isFeedLink(originalUri)) {
    newUri = originalUri + '.xml';
  } else if (!hasExtension(originalUri)) {
    newUri = originalUri + '/index.html';
  }

  request.uri = newUri;

  return request;
}