Consider adding a feature to allow actions and loaders know about why the request was triggered.

[hasanayan]

Our authentication flow involves redirecting the user to a page and then back to where they were (or where they wanted to go). This is initiated from actions or loaders. When determining what url to redirect the client to we need to be able to know if the request to loader/action was because of navigation or a background fetch.

Here is what I mean by navigation and background fetch:
navigation: Requests due to useLoaderData (except for the requests due to revalidation of the loader data), These happen when the url changes
background fetch: Requests due useFetcher and revalidation of useLoaderData, requests posting forms. These happen without a url change

If we could distinguish between these two in our loaders and actions we can do the following:

request is due to navigation -> redirect to request url (where the client wanted to go)
request is due to background fetch -> redirect to Referer if it matches our url

We solved this issue for ourselves by patching @remix-run/router as follows:
1- add X-Request-Type: fetch header to all requests created by createClientSideRequest
2- in revalidate function, pass isRevalidation: true to startNavigation function as part of opts (3rd) argument.
3- in startNavigation check if opts?.isRevalidation is true, if not, set X-Request-Type: navigation header on the request