From 8aaf923260b4920c21c087c4d8b3618639aed071 Mon Sep 17 00:00:00 2001
From: mihailik <mihailik@gmail.com>
Date: Thu, 18 Feb 2016 21:43:10 +0000
Subject: [PATCH] Firefox has Object.prototype.watch

---
 src/compiler/tsc.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/compiler/tsc.ts b/src/compiler/tsc.ts
index 59212ed849b..93be03398e1 100644
--- a/src/compiler/tsc.ts
+++ b/src/compiler/tsc.ts
@@ -415,7 +415,8 @@ namespace ts {
 
             const compileResult = compile(rootFileNames, compilerOptions, compilerHost);
 
-            if (!compilerOptions.watch) {
+            // Firefox has Object.prototype.watch
+            if (!compilerOptions.watch || !compilerOptions.hasOwnProperty("watch")) {
                 return sys.exit(compileResult.exitStatus);
             }
 
@@ -441,7 +442,8 @@ namespace ts {
             }
             // Use default host function
             const sourceFile = hostGetSourceFile(fileName, languageVersion, onError);
-            if (sourceFile && compilerOptions.watch) {
+            // Firefox has Object.prototype.watch
+            if (sourceFile && compilerOptions.watch && compilerOptions.hasOwnProperty("watch")) {
                 // Attach a file watcher
                 const filePath = toPath(sourceFile.fileName, sys.getCurrentDirectory(), createGetCanonicalFileName(sys.useCaseSensitiveFileNames));
                 sourceFile.fileWatcher = sys.watchFile(filePath, (fileName: string, removed?: boolean) => sourceFileChanged(sourceFile, removed));