From 657b4970c759a7232e45e7ecebfe0b0b07d2f9a6 Mon Sep 17 00:00:00 2001
From: Joe <josephnumainville@deephaven.io>
Date: Wed, 5 Jun 2024 15:08:39 -0500
Subject: [PATCH] check for ServiceWorker (#42)

---
 src/widget.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/widget.ts b/src/widget.ts
index 0385a27..8864744 100644
--- a/src/widget.ts
+++ b/src/widget.ts
@@ -117,7 +117,8 @@ export class DeephavenView extends DOMWidgetView {
     if (
       source == null ||
       source instanceof MessagePort ||
-      source instanceof ServiceWorker ||
+      (typeof ServiceWorker !== 'undefined' &&
+        source instanceof ServiceWorker) ||
       source !== this.iframe.contentWindow
     ) {
       log.debug('Ignore message, invalid event source', source);