A Client Quits Will Cause The Server Down

[Kenzku]

When it happen:

I opened two clients in different windows on Safari. One sent a message and the other could received, but if either of the clients quit, such as by close the window, it would trigger an error on the server.

What is the output:

The Node.js output says:

wamp.io/lib/server.js:90
      delete self.topics[topic][client.id];
                                      ^
TypeError: Cannot convert null to object
    at WebSocket.Server.onConnection (/Users/Ken/Documents/Projects/wamp.io/lib/server.js:90:39)
    at WebSocket.EventEmitter.emit (events.js:123:20)
    at WebSocket.cleanupWebsocketResources (/Users/Ken/Documents/Projects/wamp.io/node_modules/ws/lib/WebSocket.js:649:23)
    at Socket.EventEmitter.emit (events.js:90:17)
    at TCP.onread (net.js:417:51)

What I thought:

If added one line before the delete self.topics[topic][client.id];

console.log(self.topics[0]);

it outputs undefined, moreover.

the self.topics looks like an object rather than an array, e.g.:

{ 'event:firstevent': { '585972943854826': true } }

[Kenzku]

I couldn't understand what does the following line does,

90 delete self.topics[topic][client.id];

but it seems if changed to this way might work:

var toplicsKeys = Object.keys(client.topics);
      for (var topic in toplicsKeys) {
          delete self.topics[toplicsKeys[topic]][client.id];
      }

So, could you please also explain what is your code does on client.on('close, function(){ ... }); in lib/server.js