feat(graphql-ruby-client): support graphql-ws and GraphiQL for Subscription over ActionCable

[choznerol]

(Probably cloud help) close rmosolgo/graphiql-rails#90, #2658

graphql-ruby already has client side support for Apollo Subscription and Relay Subscription, but GraphiQL (thus graphiql-rails) seems to use graphql-ws under the hood therefore Subscription is not supported in /graphiql.

This draft PR aims to support graphql-ws client like Apollo Subscription and Relay Subscription did, hoping to make Subscription works for GraphiQL client.

Progress

• javascript client interface
• basic implementation
• unit test
• testing with with GraphiQL or graphql-ws

[choznerol]

Have been using browser extension Altair GraphQL Client, which supports many GraphQL Subscription transport protocols, including graphql-ws and Rails ActionCable.

While supporitng graphql-ws might still be valuable, since the primary goal for this PR was to be able to use GraphiQL (or any similar tool) for Subscription over ActionCable and there is an existing tool for this, I'll close this PR for now.

[bmulholland]

So graphql-ws support was never added? I'd like to use it

[rmosolgo]

It's been a while, but in case anyone still finds it helpful, graphql-ruby-client now includes a GraphiQL "fetcher" for using ActionCableSubscriptions: https://graphql-ruby.org/javascript_client/graphiql_subscriptions.html