Support for custom Search Params in the redirectTo option URL

[413n]

I have a middleware using withAuthMiddleware that redirects the user to the homepage with a custom Search param and seems to not be supported because I get to this broken link: http://localhost:3000/%3Ferror=notAuthorized?redirectedFrom=%2Fprotected%2Fpage

My code

import { withMiddlewareAuth } from "@supabase/auth-helpers-nextjs/middleware";

export const middleware = withMiddlewareAuth({
  redirectTo: "/?error=notAuthorized",
});

Debugging the code, I found the part below where we can see that the redirectTo is set as pathname and then a SearchParam is set. This is the part that could be more flexible.

https://github.com/supabase-community/auth-helpers/blob/9b4225133a5f3a617819570bd172af3cdb8ac7cb/packages/nextjs/src/middleware/withMiddlewareAuth.ts#L142-L159

Proposal

What if we check that the redirectTo is an instanceof URL (https://developer.mozilla.org/en-US/docs/Web/API/URL/URL) and eventually avoiding setting it to the pathname but using that to set the SearchParam?

Or eventually an additional check should be done to initialize the given URL string

[thorwebdev]

This will be enabled via #364