Start: createServerFn cannot return raw response objects

[nekochan0122]

Which project does this relate to?

Start

Describe the bug

Server functions should able to return Raw Response objects.

Your Example Website or App

https://github.com/nekochan0122/tanstack-start-return-response-object

Steps to Reproduce the Bug or Issue

1. Open the dev server
2. Click the "Trigger serverFn" button
3. See the console output and cookies

Expected behavior

const serverFn = createServerFn({ method: "POST" }).handler(async () => {
  return new Response(JSON.stringify({ hello: "world" }), {
    status: 200,
    headers: {
      "Content-Type": "application/json",
      "Set-Cookie": "test=test",
    },
  });
});

1. The console output is expected to contain { hello: "world" }
2. The cookie should be set to test=test

Screenshots or Videos

No response

Platform

• OS: [e.g. macOS, Windows, Linux]
• Browser: [e.g. Chrome, Safari, Firefox]
• Version: [e.g. 91.1]

Additional context

No response

[nekochan0122]

a temporary solution:

async function handleResponse<ResponseBody = unknown>(response: Response): Promise<ResponseBody> {
  const event = getEvent()

  setHeaders(event, Object.fromEntries(response.headers))

  switch (response.headers.get('Content-Type')) {
    case 'application/json':
      return response.json() as ResponseBody

    default:
      return response.body as ResponseBody
  }
}