Async operation before send

Hello everyone!

I need to save some important data every time when the response is already available.

I have tried 2 approaches:

1. api.finally - does not allow us to use an async callback.

api.finally(async (req, res) => {
  await saveAudit(req, res)
  res.cors()
  console.log('done')
})

2. Tried to override the method res.send in a middleware - it looks like the send method can not include any async operations.

function auditHandler (handler) {
  return (req, res, next) => {
    res.sendRes= res.send
    res.send = function (body) {
      const data = {}
      saveAudit(data)
      .finally(() => {
        console.log('finally', resData)
        res.sendRes.call(this, body)
      })
    }
    next()
  }
}

As a result - the API does not work, but it works if we do not wait for an asynchronous operation.

The issue names api.finally and a res.send override as the relevant response-lifecycle entry points. Start by tracing those paths in the framework and checking how middleware and response completion are tested. The issue names no files or tests and does not define an accepted behavior, so completion requires maintainer agreement on the async ordering.