"phx_join" is never sent if socket is not open by the time `Join` is called

Creating a channel and immediately joining it will cause the “phx_join” message to be stuck in Channel’s sendBuffer forever, if the underlying WebSocket is not open by the time Join is called.

Example code:

var fooChannel = _socket.MakeChannel("foo");
fooChannel.Join(new Dictionary<string, object>(), _timeout)

The second line will eventually call Socket.Push(Message). That method will check if the channel’s socket is already in state Open. If it isn’t, it will return false which will cause its calling method, Channel.Push(Push, TimeSpan?), to add the “phx_join” message to its sendBuffer. But FlushSendBuffer is only called in OnJoinReply. So it can’t ever be sent and the channel will never be joined.

[arne-schroppe]

@Mazyod I’ll have a look and write my feedback in the PR. And thanks for spending time on fixing this!

[Mazyod]

I haven’t revisited the reference Phoenix client implementation in a while… but it seems the sendBuffer is now the responsibility of the socket object, which makes more sense.

I’ll look into revising the implementation and updating it to be consistent with the reference implementation from the official phoenix framework repository.

Once that’s done, I’ll add a test case with your scenario and hope it will simply pass 😃

https://github.com/phoenixframework/phoenix/blob/master/assets/js/phoenix/socket.js#L94