Hystrix command property caching

hystrix.clj

(def init-fn-timeout (atom 5000))
(def init-fn-called (atom 0))

(defcommand init-fn-test-command
  {:hystrix/group-key "init-fn-test-command"
   :hystrix/thread-pool-key "init-fn-test-command"
   :hystrix/init-fn (fn [hystrix-map setter]
                      (swap! init-fn-called inc)
                      (let [prop-setter (. com.netflix.hystrix.HystrixCommandProperties Setter)]
                        (doto setter
                          (.andCommandPropertiesDefaults
                            (doto prop-setter
                              (.withExecutionIsolationThreadTimeoutInMilliseconds @init-fn-timeout)))))) }
  [])

(deftest test-init-fn
  (testing "properties are applied to command when instantiated"

    (let [; make sure init-fn is called on every instantiation
          _ (reset! init-fn-called 0)

          ; create command with 5000 timeout
          _ (reset! init-fn-timeout 5000)
          c0 (instantiate #'init-fn-test-command)
          c0-timeout (-> c0 .getProperties .executionIsolationThreadTimeoutInMilliseconds .get)

          ; create command with 6000 timeout
          _  (reset! init-fn-timeout 6000)
          c1 (instantiate #'init-fn-test-command)
          c1-timeout (-> c1 .getProperties .executionIsolationThreadTimeoutInMilliseconds .get)
          ]
      (is 2 @init-fn-called)
      (is (= 5000 c0-timeout))

      ; This fails because 5000 is cached forever after the first time a command is instantiated.
      (is (= 6000 c0-timeout)))))