From dc7c130f2cd05d06b4d9fe15e16913685aa88175 Mon Sep 17 00:00:00 2001
From: Luca Forstner <luca.forstner@sentry.io>
Date: Thu, 28 Mar 2024 08:18:33 +0000
Subject: [PATCH] fix(tracing-internal): Guard for missing navigation
 performance entries

---
 packages/tracing-internal/src/browser/metrics/index.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/packages/tracing-internal/src/browser/metrics/index.ts b/packages/tracing-internal/src/browser/metrics/index.ts
index 364a1617112b..af9066f46373 100644
--- a/packages/tracing-internal/src/browser/metrics/index.ts
+++ b/packages/tracing-internal/src/browser/metrics/index.ts
@@ -541,7 +541,12 @@ function setResourceEntrySizeData(
  * ttfb information is added via vendored web vitals library.
  */
 function _addTtfbRequestTimeToMeasurements(_measurements: Measurements): void {
-  const navEntry = getNavigationEntry() as TTFBMetric['entries'][number];
+  const navEntry = getNavigationEntry();
+
+  if (!navEntry) {
+    return;
+  }
+
   const { responseStart, requestStart } = navEntry;
 
   if (requestStart <= responseStart) {