Calling reply() asynchronously doesn't register timeout

[leoedin]

This seems to be related to the discussion in this closed issue.

The Problem

If you send a message to which the receiver doesn't reply immediately, you don't get notified if it later times out.

The problem is that:

1. If the receiving callback doesn't immediately reply() to the message, its automatically acknowledged
2. When the _processQueues() function is run, if a message has timed out and ack() has been called, it's deleted from the sent queue.
3. Our onReply() function is never called, but neither are our onTimeout() or onFail() functions
4. We're left wondering what happened to the data we were expecting

Fix

Change the check in _processQueues() to call the onTimeout function if there's an onReply function defined.

if (!msg._acked) {

changes to
if ((!msg._acked) || (_isFunc(msg._onReply))) {

Example Code

This setup works:

Sending side

mm.send( 
  "EXAMPLE",
 {},
  {
      onFail      = function( message, reason, retry ) { server.log("FAIL"); },
      onTimeout   = function( message, wait, fail ) { server.log("TIMEOUT"); fail(); },
      onReply     = function( message, response ) { server.log("REPLY: " + response); },
      onAck = function(message) { server.log("ACK"); }
  }, 
  5, // Timeout of 5 seconds
  null ); 

Receiving side

mm.on( "EXAMPLE", function( message, reply ) {
  imp.wakeup( 1.0, function() {  reply("OUR REPLY"); }.bindenv(this) );
});

Results:

ACK
REPLY: OUR REPLY

But, if we change the timeout and the asynchronous delay, we don't get any notification. If the receiver delays for 10 seconds imp.wakeup( 10.0, function() { reply("OUR REPLY"); }.bindenv(this) ); then what we see is:

ACK
/// That's it...

Pull Request

This change is a bit opinionated - so I haven't made a PR yet, but I'm happy to if you agree it's a good approach.