From 3c4c36068e0ead8d3442da59f46cd72d68a908bb Mon Sep 17 00:00:00 2001
From: Yoshihiro Kikuchi <yknetg@gmail.com>
Date: Thu, 14 Jul 2011 15:14:44 +0900
Subject: [PATCH] fs: added an argument check in fs.watchFile

Fixes #1324.
---
 lib/fs.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/fs.js b/lib/fs.js
index 29e1a3d2b1d..b907021b5cc 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -629,6 +629,10 @@ fs.watchFile = function(filename) {
     listener = arguments[1];
   }
 
+  if (!listener) {
+    throw new Error('watchFile requires a listener function');
+  }
+
   if (options.persistent === undefined) options.persistent = true;
   if (options.interval === undefined) options.interval = 0;