Promisify getAndPassUp

lib/multi_caching.js

@@ -132,15 +132,15 @@ var multiCaching = function(caches, options) {
      * @param {function} cb
      */
     self.getAndPassUp = function(key, cb) {
-        return getFromHighestPriorityCache(key, function(err, result, index) {
+        var promised = false;
-            if (err) {
+        if (!cb) {
-                if (cb) {
+            promised = true;
-                    return cb(err);
+            cb = Promise.defer();
-                }
+        }
-            }
 
-            if (cb) {
+        getFromHighestPriorityCache(key, function(err, result, index) {
-                cb(err, result);
+            if (err) {
+                return (!promised) ? cb(err) : cb.reject(err);
             }
 
             if (index) {
@@ -153,7 +153,13 @@ var multiCaching = function(caches, options) {
                     }
                 });
             }
+
+            return (!promised) ? cb(err, result) : cb.resolve(result);
         });
+
+        if (promised) {
+            return cb.promise;
+        }
     };
 
     /**