A type guard for vals that expect a WebApi Request as the first parameter.

Since a val can be invoked by run, web, express or even email, the correct type for a web endpoint should be req?: Request | unknown.

By using this type guard and handling the false case, all later code can safely access the request:

export const myVal = (req?: Request | unknown) => {
  if (!@karfau.isRequest(req)) {
    return `This val has to be used with the web endpoint, see ${@neverstew.thisValUrl()}`;
  }
  if (req.method === 'GET') {
    // ...
  }
}

Migrated from folder: web/isRequest