From 4862dcd46dc51e389fb9290fa27315a6a1079e02 Mon Sep 17 00:00:00 2001
From: Joe Herman <joeh@visibleworld.com>
Date: Tue, 13 Oct 2015 12:17:18 -0400
Subject: [PATCH] async: Remove error requirement in series, parallel.

---
 async/async.d.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/async/async.d.ts b/async/async.d.ts
index 78523d9c6..6054e9a47 100644
--- a/async/async.d.ts
+++ b/async/async.d.ts
@@ -10,7 +10,7 @@ interface AsyncResultCallback<T> { (err: Error, result: T): void; }
 interface AsyncResultArrayCallback<T> { (err: Error, results: T[]): void; }
 interface AsyncResultObjectCallback<T> { (err: Error, results: Dictionary<T>): void; }
 
-interface AsyncFunction<T> { (callback: (err: Error, result?: T) => void): void; }
+interface AsyncFunction<T> { (callback: (err?: Error, result?: T) => void): void; }
 interface AsyncIterator<T> { (item: T, callback: ErrorCallback): void; }
 interface AsyncForEachOfIterator<T> { (item: T, key: number, callback: ErrorCallback): void; }
 interface AsyncResultIterator<T, R> { (item: T, callback: AsyncResultCallback<R>): void; }
@@ -126,7 +126,7 @@ interface Async {
     during(test: (testCallback : (error: Error, truth: boolean) => void) => void, fn: AsyncVoidFunction, callback: (err: any) => void): void;
     doDuring(fn: AsyncVoidFunction, test: (testCallback: (error: Error, truth: boolean) => void) => void, callback: (err: any) => void): void;
     forever(next: (errCallback : (err: Error) => void) => void, errBack: (err: Error) => void) : void;
-    waterfall(tasks: Function[], callback?: (err: Error, result: any) => void): void;
+    waterfall(tasks: Function[], callback?: (err: Error, results?: any) => void): void;
     compose(...fns: Function[]): void;
     seq(...fns: Function[]): void;
     applyEach(fns: Function[], argsAndCallback: any[]): void;           // applyEach(fns, args..., callback). TS does not support ... for a middle argument. Callback is optional.