From 585420e9fae2ee381ed64d7b92cd4b773f0d7ca3 Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Tue, 9 Oct 2018 08:42:27 -0700
Subject: [PATCH] Updated callback signature

---
 src/compiler/sys.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index 5aaa331f586..0f90748f3c0 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -846,7 +846,7 @@ namespace ts {
                 }
             }
 
-            type FsWatchCallback = (eventName: "rename" | "change", relativeFileName: string) => void;
+            type FsWatchCallback = (eventName: "rename" | "change", relativeFileName: string | undefined) => void;
 
             function createFileWatcherCallback(callback: FsWatchCallback): FileWatcherCallback {
                 return (_fileName, eventKind) => callback(eventKind === FileWatcherEventKind.Changed ? "change" : "rename", "");