sample.clj

(defn convert-stream [f-sink f-src s]
  (let [sink (s/stream)
        src (s/map f-src s)]
    (s/connect-via sink #(s/put! s (f-sink %)) s)
    (s/splice sink src)))

(defn make-duplex-stream []
  (let [sink (s/stream)
        src (s/stream)
        duplex (s/splice sink src)]
    [sink src duplex]))

(defn test-convert-stream []
  (let [[conn-sink conn-src fake-conn] (make-duplex-stream)
        msgs (convert-stream u/->json u/json-> fake-conn)]
    ;; serialized message from mock client
    (s/put! conn-sink "{\"message\": \"hello\"}")
    ;; should be decoded from JSON
    (prn 'got @(s/take! msgs))

    ;; send unserialized message to mock client
    (s/put! msgs {"message" "bye"})
    ;; shoild be serialized JSON 
    (prn 'to-be-sent @(s/take! conn-src))))