Event acking

[Ruby184]

Proposed changes

Add event acking functionality for events (request - response flow). For details see feature request discussion #61. Changes are dependent on adonis-websocket-packet changes (new packet types and methods) - We first need to merge packet changes. PRs in other repositories as well as tests and documentation update will follow.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have read the CONTRIBUTING doc
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works.
• I have added necessary documentation (if appropriate)

Further comments

Server:

socket.on('hello', (name) => {
  // resolved with no value
})
// this is the ack response when all callbacks return resolved promise
// because we take first non-undefined resolved value as response
socket.on('hello', (name) => {
  return 'resolved'
})
socket.on('hello', (name) => {
  throw new Error('rejected')
})
// in Ws controller
async onHello (name) {
  return 'resolved'
}

Client:

socket.emit('hello', 'world', (err, data) => {
  if (err) {
    return console.log(err.message) // rejected
  }
  console.log(data) // 'resolved' if error was not thrown from one of event callbacks
})

[coveralls]

Coverage decreased (-8.6%) to 85.068% when pulling f106349 on Ruby184:event-ack into 1d99b9a on adonisjs:develop.

[AddoSolutions]

This looks great! Any way to get this bad boy polished off?