queueBindOk event called twice

[waynebrantley]

You will see 6 messages arrive in the queue. 'declare' is output once. 'bind' is output twice

require('../setup').Init('Hello World.');
var connect = require('amqp').createConnection();
var messages = [];
messages.push(' (\\-/)');
messages.push(" ('.')  –> hello world");
messages.push('(") (")');

connect.on('ready', function() {
    var ex = connect.exchange();
    var q = connect.queue('hello');
    q.on('queueDeclareOk', function(args) {
        console.log('declare');
        q.bind('#');
        q.on('queueBindOk', function() {
        console.log('bind');
            messages.forEach(function(message) {
                ex.publish('hello', message, {});
            });
        });
    });
});

[davedoesdev]

The second call is a result of this in Queue.prototype._onMethod:

    case methods.queueDeclareOk:
      this.state = 'open';
      this.name = args.queue;
      this.connection.queues[this.name] = this;

      // Rebind to previously bound exchanges, if present.
      // Important this is called *before* openCallback, otherwise bindings will happen twice.
      // Run test-purge to make sure you got this right
      _.each(this._bindings, function(exchange, exchangeName){
        _.each(exchange, function(count, routingKey){
          self.bind(exchangeName, routingKey);
        });
      });

I'm guessing your bind gets in first.

[davedoesdev]

This only displays bind once:

var connect = require('amqp').createConnection();
var messages = [];
messages.push(' (\\-/)');
messages.push(" ('.')  -> hello world");
messages.push('(") (")');

connect.on('ready', function() {
    var ex = connect.exchange();
    var q = connect.queue('hello', function () {
        console.log('declare');
        q.bind('#');
        q.on('queueBindOk', function() {
            console.log('bind');
            messages.forEach(function(message) {
                ex.publish('hello', message, {});
            });
        });
    });
});

[waynebrantley]

Seems like original should not display twice though, huh?

[davedoesdev]

Yes, it doesn't seem right to display twice. However, this module is quite a high-level wrapper over amqp so it may be that queueBindOk is caught in order to rebind the queue when reconnecting (or something like that). It seems each queue uses a separate channel so waiting until the channel is open (which is what the callback to queue does) looks like the 'approved' way of doing it.