Question

The scenario I try to resolve is a s follows, I have a testing program that makes a web to a web endpoint on a system.

This test program has a jetty web server running on which it expects a callback from the external system that completes a successful test cycle. In case that the callback is not received during an specific time range (timeout), the test fails.

To achieve this, I want the test runner to wait on an “event” that the jetty handler will set upon callback.

I thought about using java’s CyclicBarrier but I wonder if there is an idiomatic way in clojure to solve this.

Thanks

Answer 1

You can use promise you asked about recently 🙂 Something like this:

(def completion (promise))

; In test runner.
; Wait 5 seconds then fail.
(let [result (deref completion 5000 :fail)]
   (if (= result :success) 
     (println "Great!") 
     (println "Failed :(")))

; In jetty on callback
(deliver completion :success)