Add connection-init-payload for websocket

[gabrielnau]

Hello,

This is a follow-up of the discussion here: #19

We need to send connection_init message before any other one, that's why I propose a new handler ::connection-init that can be prepended in ::on-ws-open dispatch.

As for the changes in the tests, I had to mock ::internals/send-ws because some tests don't override it and the thus they try to send a message on a websocket that doesn't exist.

[gabrielnau]

@oliyh I've found an issue today testing my patch where I would send messages over websocket before the connection_init message was sent. My second commit is an attempt to ensure nothing goes on the wire until the connection is acknowledged.

[oliyh]

Hi

Thanks for the PR. Am I right in thinking that your second change is unrelated to this feature? It feels like it should be a separate issue, to wait for the ack before sending any messages.

Regarding your implementation of connection-init I haven't had a chance to look at it properly yet but I hope to do so soon. I didn't think it would be necessary to add any more event handlers so I want to understand it properly.

Thanks

[gabrielnau]

Hello,

Yes you're right, the use case where I need to wait for an ack is typically authentication. I can elaborate on that if you want ?

On the other hand, my understanding is that in the "protocol" (source needed), it is expected to do so. I wonder if that's a goal to match apollo's behavior or not ?

Thanks.

[oliyh]

Hi @gabrielnau

I have merged your first commit and made one small change such that :connection-init-payload nil will not send any message at all. Thank you for the contribution!

Your second change is a separate issue which I want to deal with separately, could you open a new PR for that?

Thanks
Oliy

[gabrielnau]

Hi @oliyh,

Thanks for the review. I'm actually not sure of the proper way to handle the use case I had in re-graph. Before going forward I should have a look at apollo's implementation first and come back with clearer ideas. I hope to do that soon.

Gabriel