PerConnectionApolloHandler sends wrong sub-protocol

[westito]

I tried subscribe with Postman but it fails with Server sent no subprotocol:

I found that the client sends graphql-transport-ws sub-protocol but server only tests to graphql-ws because getSubProtocols() return only that. The official protocol is the graphql-transport-ws as you see here: https://github.com/enisdenjo/graphql-ws/blob/master/PROTOCOL.md

[westito]

Meanwhile I realised the implemented protocol simply older than the currently recommended that Postman uses.

[kaqqao]

Yes, true. I figured there's no point in implementing the new protocol in SPQR since Spring itself already does. I'll release SPQR Starter 2.0.0.rc1 soon, possibly even today. The new version removes SPQR's entire communication layer and uses Spring directly. This will obviously be a breaking change, but it shouldn't cause too much trouble.
In the meantime, it's possible to already use Spring for communication with the current SPQR starter. I've been using it in production like that myself ever since Spring for GraphQL was released. It's pretty straightforward, I can post an example later.