From c244306514a7e338a17c2a1b9f2e3959308435cb Mon Sep 17 00:00:00 2001
From: zhengbli <zhengbli@microsoft.com>
Date: Fri, 15 Jan 2016 16:55:25 -0800
Subject: [PATCH] address CR feedback: use typeof check instead of checking
 undefined and null value

---
 src/compiler/sys.ts | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index 1a97e9c8d0a..bf25d39aa43 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -376,13 +376,11 @@ namespace ts {
                 /**
                  * @param watcherPath is the path from which the watcher is triggered.
                  */
-                function fileEventHandler(eventName: string, relativefileName: string, baseDirPath: Path) {
+                function fileEventHandler(eventName: string, relativeFileName: string, baseDirPath: Path) {
                     // When files are deleted from disk, the triggered "rename" event would have a relativefileName of "undefined"
-                    /* tslint:disable:no-null */
-                    const filePath = relativefileName === undefined || relativefileName === null
+                    const filePath = typeof relativeFileName !== "string"
                         ? undefined
-                        : toPath(relativefileName, baseDirPath, createGetCanonicalFileName(sys.useCaseSensitiveFileNames));
-                    /* tslint:enable:no-null */
+                        : toPath(relativeFileName, baseDirPath, createGetCanonicalFileName(sys.useCaseSensitiveFileNames));
                     if (eventName === "change" && fileWatcherCallbacks.contains(filePath)) {
                         for (const fileCallback of fileWatcherCallbacks.get(filePath)) {
                             fileCallback(filePath);