Prior to Next.js 12.1, we allowed passing relative URLs. However, constructing a request with new Request(url) or running fetch(url) when url is a relative URL does not work. For this reason and to bring consistency to Next.js Middleware, this behavior has been deprecated and now removed.
Reverts the changes in #35, where are not compatible with more recent NextJS versions (> 12.1), which require an absolute URL: