FXA-7936 - Fix DNT check in Safari (#1803)

`window.external` is [not available in Safari](https://developer.mozilla.org/en-US/docs/Web/API/Window/external#browser_compatibility). We need to check if it exists before calling it in order to not break the page load.
mozilla · Jul 11, 2023 · f962462 · f962462
1 parent 73cbdcd
commit f962462
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/telemetry/index.js b/src/telemetry/index.js
@@ -17,7 +17,8 @@ const isDNTEnabled =
   navigator.doNotTrack === "yes" ||
   navigator.doNotTrack === "1" ||
   navigator.msDoNotTrack === "1" ||
-  ("msTrackingProtectionEnabled" in window.external &&
+  (typeof window.external !== "undefined" &&
+    "msTrackingProtectionEnabled" in window.external &&
     window.external.msTrackingProtectionEnabled());
 
 /**