version2.clj

(defn with-error-handling [f]
  (fn [& args]
    (try
      (if-let [res (apply f args)]
        [res nil]
        [nil {:message (str "Had nil returned calling " f " with " args)}]
      (catch Exception e
        [nil {:exception e :message (str "Had exception calling " f " with " args)}]))))

(defn our-comp
  "Same as `clojure.core/comp` except that the functions will shortcircuit on nil.
  ((comp inc inc) 1) => 3
  ((comp inc inc) nil) => nil"
  [& fs]
  (fn comp-fn
    ([i] (comp-fn i fs))
    ([[i e] [f & more]]
     (cond (nil? i) [nil e]
           (nil? f) [i e]
           :else (recur (f i) more)))))

(def transform
  (->> [:data
        transform-1
        transform-2
        transform-3
        transform-4
        transform-5
        transform-6
        transform-7]
        (map with-error-handling)
        (apply new-comp)))

(defn process-errors! [[v e]]
  (when e
    (let [{:keys [message exception]} e]
      (when exception (airbrake/notify config/airbrake exception))
      (log/error message)))
  v)
  
(defn process-clicks-messages [db-connection objs]
  (->> objs
       (map transform)
       (map process-errors!)
       (remove nil?)
       (run! (partial db/save-objects! db-connection))))