byebye message not sent when calling bus.stop()

[davidatingenuity]

HI @achingbrain,
I'm using your library, and integrating it with express, as per your example:
const upnp = require('@achingbrain/ssdp')(options.ssdpOptions);
const ssdp = require('./ssdp/ssdp');
upnp.on('error', console.error) // Log errors
.advertise(ssdp.services) // Advertise the services configured
.then(ssdp.serviceHosting) // Configure Express to serve the details.xml file
.then(addRoutes); // then add all the other routes

where:

• options.ssdpOptions specifies a guid for the udn,
• ssdp.services contains the USN, the location and the details for the service,
• ssdp.serviceHosting contains the routing for express, and
• addRoutes adds all the remaining routes to express.

To get to this point, I needed to modify stop-advert.js slightly. To integrate with express, I need to specify a location, but if the location is specified, no shutdownServers function is created in create-location.js, and an unhandled promise rejection is thrown in stop-advert.js when it tries to call plumbing.shutdownServers. All I'm doing is checking if shutdownServers exists before it's called.

The issue I'm having is when I call upnp.stop(), a transport:outgoing-message is emitted for the byebye, but I never see the corresponding packet in wireshark. The socket.send call never seems to return.

I can submit a PR for the unhandled promise rejection, but I'm stuck on the other issue. Any ideas?

[achingbrain]

Please do submit a PR, that sounds like it should be handled - thanks.

The actual sending of the UDP message will likely be done asynchronously - Is the process shutting down before the packet gets sent?

[davidatingenuity]

I've submitted #6, but upon further inspection, it looks like the 2nd issue is a result of my fix for the first - the nested promises are being processed in parallel, not sequentially as I expected. This means the sockets are closed before the broadcastAdvert has finished.

[davidatingenuity]

I couldn't work out how to wait until the byebye broadcast event had finished, so I've put a 1 second delay between the broadcastAdvert and when the sockets are closed. It's not pretty, but it works well enough for our purposes. I'll let someone more capable than I fix it properly, but if you're interested, my fix is here: davidatingenuity@7fc6475