Callback exceptions are swallowed

[vincentjames501]

Issue

If there is an exception that is thrown inside of a http-kit response callback, nothing is ever logged anywhere (unless it is derefed).

Steps

(deftest exception-handling
  (testing "Inside fake-http"
    (fake-http/with-fake-http
      ["https://google.com" 200]
      (http/get "https://google.com"
                (fn [resp] (throw (Exception. "Inside logged?"))))))
  (testing "outside fake-http"
    (http/get "https://google.com"
              (fn [resp] (throw (Exception. "Outside logged?"))))))

Output

Ran 1 test containing 0 assertions.
No failures.
Wed Apr 26 16:05:48 CDT 2017 [client-worker-2] ERROR - GET https://www.google.com/'s callback
java.lang.Exception: Outside logged?

Possible Solution

Inside responder-wrapper it may just be appropriate to log similar to how http-kit does:

(try ((or callback identity) %1)
                                    (catch Throwable e
                                      ;; dump stacktrace to stderr
                                      (HttpUtils/printError (str method " " url "'s callback") e)
                                      ;; return the error
                                      {:opts opts :error e}))