Stop (inconsistently) mutating request.url

[aaronadamsCA]

Remix strips its internal params (currently index, _data, and _routes) from request.url after calling getLoadContext(), but before calling loader() or action(). So the value of request.url is different depending on where you access it.

This is very surprising behaviour that leads to mistakes. It's already caused us issues in two separate apps.

I'd like to suggest a future flag that stops Remix from mutating request, and a new way to access the "clean" URL.

• This could be a new utility with the signature (request: Request) => URL.
• But given how incredibly often we need to access the URL, I'd much rather just see Remix pass a clean url: URL to getLoadContext(), loader(), action(), and the others.

Notable that @jacob-ebey wrote this a couple of years back:

remix/packages/remix-server-runtime/data.ts

Lines 116 to 120 in d7f4015

	// TODO: Document these search params better
	// and stop stripping these in V2. These break
	// support for running in a SW and also expose
	// valuable info to data funcs that is being asked
	// for such as "is this a data request?".

Related discussion: #9058