defaults.server.ts

import { HeadersFunction } from "@remix-run/node"

export const serverTimingHeaders: HeadersFunction = ({
  loaderHeaders,
  parentHeaders,
}) => {
  return setServerTimingHeaders(new Headers(), {
    loaderHeaders,
    parentHeaders,
  })
}
export function setServerTimingHeaders(
  headers: Headers,
  args: {
    loaderHeaders: Headers
    parentHeaders: Headers
  },
) {
  if (args.loaderHeaders.has("Server-Timing")) {
    headers.set(
      "Server-Timing",
      args.loaderHeaders.get("Server-Timing")!,
    )
  }
  if (args.parentHeaders.has("Server-Timing")) {
    headers.append(
      "Server-Timing",
      args.parentHeaders.get("Server-Timing")!,
    )
  }
  return headers
}