From b60f936b141a73096492756ee838836f4b146010 Mon Sep 17 00:00:00 2001
From: Oleg Mihailik <mihailik@gmail.com>
Date: Tue, 20 Jun 2017 22:54:50 +0100
Subject: [PATCH] Enquote undefineds.

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

diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 7b508351aec..0bea9468432 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -1053,7 +1053,7 @@ namespace ts {
                     errors.push(createDiagnosticForNodeInSourceFile(sourceFile, element.name, extraKeyDiagnosticMessage, keyText));
                 }
                 const value = convertPropertyValueToJson(element.initializer, option);
-                if (typeof keyText !== undefined && typeof value !== undefined) {
+                if (typeof keyText !== "undefined" && typeof value !== "undefined") {
                     result[keyText] = value;
                     // Notify key value set, if user asked for it
                     if (jsonConversionNotifier &&