Middleware API

[jnv]

This could be used to implement: #39, #25, #44.

• Setup globally, for program
• Wraps each box in a flow
• Receives an instance of box and its metadata, can (re-)call it

[jnv]

Since box can emit unlimited amount of messages, a plain Koa-like middleware won't cut it. We can use generators though and yield to the middleware. The user-level API may look like this:

function myFancyMiddleware (ctx, next) {
  // do something before the box is called
  for (let message of next()) {
    // do something with message
    // pass the message up the middleware chain
    yield message
  }
  // do something once the box is done
}

[jnv]

Prototype here https://github.com/jnv/bakeryjs-middlewares-prototype