Async middleware support

[Akkuma]

By returning the result, middleware can now be properly asynchronous throughout the project, so you can write code like this:

async (req, res, next) => {
  const now = new Date().getTime()
  await next();
  console.log(new Date() - now);
}

[jkyberneees]

Hi @Akkuma , thanks for taking time on restana. I am afraid to say that your fix won't work as expected. Here I expose several reasons:

• restana middlewares support is focused on callback based middlewares using next() not async ones. The goal was to re-use existing express and connect middlewares.
• We still consider async middlewares but just for error handling.
• Route middlewares are executed out of the main middlewares chain.

However, you can benefit from the on response event to get the same functionality:

service.use((req, res, next) => {
  const now = new Date().getTime()

  res.on('response', ({ res }) => {
    res.setHeader('x-response-time', new Date().getTime() - now)
  })

  return next()
})

You are required to use req.send(...) to get this event triggered.

Looking forward to your feedback, Thanks and Regards