From 4610093c87975b6355f31a9c849351129908783a Mon Sep 17 00:00:00 2001
From: mcalmus <mike@calmus.org>
Date: Fri, 13 Mar 2020 08:28:40 -0400
Subject: [PATCH] fix(core): guard reading of global `ngDevMode` for undefined.
 (#36055)

When reading globals such as `ngDevMode` the read should be guarded by `typeof ngDevMode` otherwise it will throw if not
defined in `"use strict"` mode.

PR Close #36055
---
 packages/core/src/util/ng_dev_mode.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/core/src/util/ng_dev_mode.ts b/packages/core/src/util/ng_dev_mode.ts
index 7fb0579cb723e..a79f0af0f37c8 100644
--- a/packages/core/src/util/ng_dev_mode.ts
+++ b/packages/core/src/util/ng_dev_mode.ts
@@ -115,7 +115,7 @@ export function initNgDevMode(): boolean {
     if (typeof ngDevMode !== 'object') {
       ngDevModeResetPerfCounters();
     }
-    return !!ngDevMode;
+    return typeof ngDevMode !== 'undefined' && !!ngDevMode;
   }
   return false;
 }