GraphQL subscriptions over Websockets from Clojurescript on Node

graphql.cljs

;; Add to cljsbuild
;; :npm-deps     {:graphql-tag                "2.10.0"
;;                :apollo-link                "1.2.4"
;;                :apollo-link-ws             "1.0.10"
;;                :subscriptions-transport-ws "0.9.15"
;;                :ws                         "6.1.2"}
;; :install-deps true

(ns example.graphql
  (:require
    [apollo-link :refer [execute]]
    [apollo-link-ws :refer [WebSocketLink]]
    [graphql-tag :as gql]
    [subscriptions-transport-ws :refer [SubscriptionClient]]
    [ws]))

(defn client
  [{:keys [uri]}]
  (SubscriptionClient. uri #js {:reconnect true} ws))

(defn subscription
  [client query vars on-data on-err]
  (-> (WebSocketLink. client)
      (execute (clj->js {:query     (gql query)
                         :variables vars}))
      (.subscribe (fn [data] (-> (js->clj data :keywordize-keys true)
                                 :data
                                 (on-data)))
                  (fn [err] (-> (js->clj err :keywordize-keys true)
                                (on-err))))))