test.clj

(deftype Wrapper [deref-reaction deref-fn reset-fn]
  ratom/IReactiveAtom

  IDeref
    (-deref [this]
      (-deref deref-reaction))

  IHash
    (-hash [_]
      (hash deref-fn))

  IReset
    (-reset! [this newval]
      (reset-fn newval))

  ISwap
    (-swap! [this f]          (-reset! this (f @deref-reaction)))
    (-swap! [this f x]        (-reset! this (f @deref-reaction x)))
    (-swap! [this f x y]      (-reset! this (f @deref-reaction x y)))
    (-swap! [this f x y more] (-reset! this (apply f @deref-reaction x y more)))

  IPrintWithWriter
    (-pr-writer [a w opts]
      (ratom/pr-atom deref-reaction w opts "Wrapper:"))

  IWatchable
    (-notify-watches [this old new]
      (#'ratom/notify-w deref-reaction old new))
    (-add-watch [this key f]
      (#'ratom/add-w deref-reaction key f))
    (-remove-watch [this key]
      (#'ratom/remove-w deref-reaction key))

  ratom/IDisposable
    (dispose! [this]
      (ratom/dispose! deref-reaction)))

(defn wrap [deref-fn reset-fn]
  (let [deref-reaction (ratom/make-reaction deref-fn :auto-run true)]
    (Wrapper. deref-reaction deref-fn reset-fn)))