Allow route.tsx files to export functions other than GET, POST, etc

[remorses]

Goals

1. Allow route.tsx files to export other functions other than GET, POST, etc

Non-Goals

No response

Background

I am developing an alternative implementation of server actions with a custom directive here: https://github.com/remorses/server-actions-for-next-pages

An example of an actions file:

// app/action/route.ts
"poor man's use server";

export async function action({}) {
  return { headers: headers(), cookies: cookies() };
}

This file will be tranformed by a loader to create a valid route.ts file.

The problem is that Next.js during build does not allow you to have other exports other than GET, POST, etc

I think it would be better if the Typescript plugin added a warning for these cases instead of an error.

Proposal

Turn the error x is not a valid Route export field. into a warning for route files