How to use waitUntil with dev server?

[iBobik]

In the route event handler I need to send response quickly and then do some long running tasks.

Cloudflare would kill the worker after sending response, so I need to call ctx.waituntil before the return.

But how write that code universally so it will work on the node dev server and Cloudflare production environment?

I would like to avoid this:

export default defineEventHandler(async event => {
  if (event.context.ctx.waitUntil) {
    event.context.ctx.waitUntil(longRunningPromise())
  } else {
    await longRunningPromise()
  }

  return { status: 'ok' }
})

[iBobik]

Found undocumented event.waitUntil in Nitro function which calls Cloudflare’s function and also has fallback on the dev server.