From 0d32570c026c1b8a47cd38ba5bf642c72ef39a50 Mon Sep 17 00:00:00 2001
From: zhengbli <zhengbli@microsoft.com>
Date: Tue, 26 Apr 2016 14:35:51 -0700
Subject: [PATCH] add dirWatcher for "watch" option in tsconfig.json

---
 src/compiler/tsc.ts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/compiler/tsc.ts b/src/compiler/tsc.ts
index 2e40cfdc53c..d6dfc9eca8d 100644
--- a/src/compiler/tsc.ts
+++ b/src/compiler/tsc.ts
@@ -432,6 +432,16 @@ namespace ts {
                 return sys.exit(compileResult.exitStatus);
             }
 
+            if (!directoryWatcher && sys.watchDirectory && configFileName) {
+                const directory = ts.getDirectoryPath(configFileName);
+                directoryWatcher = sys.watchDirectory(
+                    // When the configFileName is just "tsconfig.json", the watched directory should be
+                    // the current directory; if there is a given "project" parameter, then the configFileName
+                    // is an absolute file name.
+                    directory == "" ? "." : directory,
+                    watchedDirectoryChanged, /*recursive*/ true);
+            }
+
             setCachedProgram(compileResult.program);
             reportWatchDiagnostic(createCompilerDiagnostic(Diagnostics.Compilation_complete_Watching_for_file_changes));
         }