LavalinkNodeConnection is cached before a successful connection is made

[Kriste00]

Summary

The LavaLinkExtention will cache a LavalinkNodeConnection even if the connection to the socket was not successful.

Details

Example:
Line 53: The connection is not cached.
Line 59: The connection gets put into the cache.
Line 60: The connection fails (Network issue, ect)

Bug: The connection is still in the cache and will be returned on the next ConnectAsync call.

DSharpPlus/DSharpPlus.Lavalink/LavalinkExtension.cs

Lines 53 to 62 in f0737fa

	if (this.ConnectedNodes.ContainsKey(config.SocketEndpoint))
	return this.ConnectedNodes[config.SocketEndpoint];
	var con = new LavalinkNodeConnection(this.Client, config);
	con.NodeDisconnected += this.Con_NodeDisconnected;
	con.Disconnected += this.Con_Disconnected;
	this.ConnectedNodes[con.NodeEndpoint] = con;
	await con.StartAsync().ConfigureAwait(false);
	return con;

[uwx]

wouldn't Con_NodeDisconnected be invoked in that case, removing it from the cache?

[Kriste00]

In my testing the connection is still there and gets returned on the next call, even tho there is no lavalink socket running.

[uwx]

Do you get Connection closed or Lavalink died on your console when the connection fails? It should remove it from the cache right before LavalinkNodeConnection.Disconnected fires.

[Kriste00]

The way i got the bug was:

1. Connect to lavalink.
2. Kill lavalink
3. Try to connect 2 times in a row, after the first attempt throws WebSocketException
4. Second attempt will return a connection even tho its not connected

[Kriste00]

NodeDisconnected will not be fired because the connection was never made. Cannot disconnect from something that was never connected.

[uwx]

Is the exception thrown by ConnectAsync, or in LavalinkSocketErrored? I think I know what's causing this issue.

[Kriste00]

By ConnectAsync
Exception thrown: 'System.Net.WebSockets.WebSocketException' in System.Net.WebSockets.dll