From 57a2e140ea419f7790b1672529f21dfe2261b52b Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Fri, 13 Jan 2023 06:11:57 +0100
Subject: [PATCH] feat: Guard against missing `window.CSSStyleSheet` (#1088)

---
 packages/rrweb/src/record/observer.ts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/packages/rrweb/src/record/observer.ts b/packages/rrweb/src/record/observer.ts
index cfc17a7e..324342e1 100644
--- a/packages/rrweb/src/record/observer.ts
+++ b/packages/rrweb/src/record/observer.ts
@@ -538,6 +538,13 @@ function initStyleSheetObserver(
   { styleSheetRuleCb, mirror, stylesheetManager }: observerParam,
   { win }: { win: IWindow },
 ): listenerHandler {
+  if (!win.CSSStyleSheet || !win.CSSStyleSheet.prototype) {
+    // If, for whatever reason, CSSStyleSheet is not available, we skip the observation of stylesheets.
+    return () => {
+      // Do nothing
+    };
+  }
+
   // eslint-disable-next-line @typescript-eslint/unbound-method
   const insertRule = win.CSSStyleSheet.prototype.insertRule;
   win.CSSStyleSheet.prototype.insertRule = function (