clean up code, use ES6waterfall-multiple-callback-defense

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/waterfall.js b/lib/waterfall.js
index e25f629..a31b3b4 100644
--- a/lib/waterfall.js
+++ b/lib/waterfall.js
@@ -15,21 +15,20 @@ export default  function(tasks, cb) {
 
     function nextTask(args) {
         if (taskIndex === tasks.length) {
-            return cb.apply(null, [null].concat(args));
+            return cb(null, ...args);
         }
-        var task = tasks[taskIndex];
-        taskIndex++;
 
         var taskCallback = onlyOnce(rest(function(err, args) {
             if (err) {
-                return cb.apply(null, [err].concat(args));
+                return cb(err, ...args);
             }
             nextTask(args);
         }));
 
         args.push(taskCallback);
 
-        task.apply(null, args);
+        var task = tasks[taskIndex++];
+        task(...args);
     }
 
     nextTask([]);