Spreading request headers object in middleware function doesn't work as per examples

[jonesty]

Perceived Problem

The headers object on the request passed to a request middleware function is of type Headers, which yields an empty object when spread. The examples in the repo show usage as below.

const requestMiddleware: RequestMiddleware = async (request) => {
  return {
    ...request,
    headers: {
      ...request.headers,
      ^^^^^^^^^^^^^^^^^^ This always yields an empty object so any headers passed to the request call are lost.
      'x-auth-token': await getAccessToken(),
    },
  }
}

Ideas / Proposed Solution(s)

I guess there's a couple of options here - modify createFetcher to convert the headers to a plain object before passing in or update the examples to show something like below.

const requestMiddleware: RequestMiddleware = async (request) => {
  const headers = new Headers(request.headers);
  headers.set('x-auth-token', await getAccessToken());

  return {
    ...request,
    headers
  }
}

[aecorredor]

+1. This just threw off for a while. It must have changed in a recent version, since it did work before.

[jasonkuhrt]

This issue doesn't need more comments, it's a docs improvement for anyone motivated. Thanks.