From b0cb4f68cd574d84dc2ec600ad02c863c565eb3f Mon Sep 17 00:00:00 2001
From: Tim Fish <tim@timfish.uk>
Date: Mon, 31 Oct 2022 10:11:36 +0100
Subject: [PATCH] Add previous check to web vitals

---
 packages/tracing/src/browser/web-vitals/getCLS.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/tracing/src/browser/web-vitals/getCLS.ts b/packages/tracing/src/browser/web-vitals/getCLS.ts
index e96d2f098ccd..52fe7e519bd0 100644
--- a/packages/tracing/src/browser/web-vitals/getCLS.ts
+++ b/packages/tracing/src/browser/web-vitals/getCLS.ts
@@ -61,6 +61,7 @@ export const onCLS = (onReport: ReportCallback, opts: ReportOpts = {}): void =>
         // entry in the current session. Otherwise, start a new session.
         if (
           sessionValue &&
+          sessionEntries.length !== 0 &&
           entry.startTime - lastSessionEntry.startTime < 1000 &&
           entry.startTime - firstSessionEntry.startTime < 5000
         ) {