dvIsErrorPageRoute function

bool dvIsErrorPageRoute(String path)

Whether path is one of the two error routes.

Reads the path as the request was written, because that is all a build gets: the same page is asked about as /offline, as /offline/ by a static host serving a directory index, and as /offline?from=%2Farticles when the worker redirected a person to it. Query and fragment are dropped first, and the route must be the whole path.

A site served under a mount is asked about its routes with the mount already stripped, the same as every other route, so a build mounts its answer rather than guessing at one here — and a nested /blog/404 is still a real page whose slug is 404, which this must not swallow.

Implementation

bool dvIsErrorPageRoute(String path) {
  if (path.isEmpty) return false;
  final Uri? uri = Uri.tryParse(path);
  if (uri == null) return false;
  if (uri.hasScheme || uri.hasAuthority) return false;
  String route = uri.path;
  while (route.endsWith('/')) {
    route = route.substring(0, route.length - 1);
  }
  return route == dvNotFoundRoute || route == dvOfflineRoute;
}