serverless-artillery/lib/lambda/node_modules/socketio-wildcard/index.js

A serverless performance testing tool. `serverless` + `artillery` = crush. a.k.a. Orbital Laziers [sic]

'use strict'
var BuiltInEmitter = require('events').EventEmitter

module.exports = function (CustomEmitter) {
  var Emitter = CustomEmitter || BuiltInEmitter
  var emit = Emitter.prototype.emit

  function onevent (packet) {
    var args = packet.data || []
    if (packet.id != null) {
      args.push(this.ack(packet.id))
    }
    emit.call(this, '*', packet)
    return emit.apply(this, args)
  }

  return function (socket, next) {
    if (socket.onevent !== onevent) {
      socket.onevent = onevent
    }
    return next ? next() : null
  }
}