message: Check type of url
diff: @@ -180,6 +180,14 @@ export default class Renderer {
  return;
  }
  + // Check that `url` is of a valid type
  + if (!["string", "function", "undefined"].includes(typeof url)) {
  + throw new Exception(
  + `The url variable must be either a string, function, or 'undefined'. The provided url is of type: ${typeof url}.`,
  + { page, url },
  + );
  + }
  +
  if (typeof url === "function") {
  url = url(page);
  }
  