From d9f3f54585024827d29d37f7d99a9d280da98e15 Mon Sep 17 00:00:00 2001
From: threadhoard-vps <yansh2017@gmail.com>
Date: Mon, 1 Jun 2026 18:45:45 +0000
Subject: [PATCH] fix: validate PerformanceObserver observe options

---
 .../performance/PerformanceObserver.js        | 20 ++++++++++++---
 .../__tests__/PerformanceObserver-itest.js    | 25 +++++++++++++++++++
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/packages/react-native/src/private/webapis/performance/PerformanceObserver.js b/packages/react-native/src/private/webapis/performance/PerformanceObserver.js
index c1b2a47a0ba9..57a0e1d89466 100644
--- a/packages/react-native/src/private/webapis/performance/PerformanceObserver.js
+++ b/packages/react-native/src/private/webapis/performance/PerformanceObserver.js
@@ -203,18 +203,30 @@ export class PerformanceObserver {
     return observerHandle;
   }
 
-  #validateObserveOptions(options: PerformanceObserverInit): void {
-    const {type, entryTypes, durationThreshold} = options;
+  #validateObserveOptions(options: ?PerformanceObserverInit): void {
+    if (options == null) {
+      throw new TypeError(
+        "Failed to execute 'observe' on 'PerformanceObserver': 1 argument required, but only 0 present.",
+      );
+    }
+
+    const {type, entryTypes, durationThreshold, buffered} = options;
 
     if (!type && !entryTypes) {
       throw new TypeError(
-        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must not include both entryTypes and type arguments.",
+        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must include either entryTypes or type arguments.",
       );
     }
 
     if (entryTypes && type) {
       throw new TypeError(
-        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must include either entryTypes or type arguments.",
+        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must not include both entryTypes and type arguments.",
+      );
+    }
+
+    if (entryTypes && buffered != null) {
+      throw new TypeError(
+        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must not include both entryTypes and buffered arguments.",
       );
     }
 
diff --git a/packages/react-native/src/private/webapis/performance/__tests__/PerformanceObserver-itest.js b/packages/react-native/src/private/webapis/performance/__tests__/PerformanceObserver-itest.js
index 41ddaa4be8f3..3924e5e24356 100644
--- a/packages/react-native/src/private/webapis/performance/__tests__/PerformanceObserver-itest.js
+++ b/packages/react-native/src/private/webapis/performance/__tests__/PerformanceObserver-itest.js
@@ -96,6 +96,31 @@ describe('PerformanceObserver', () => {
     expect(entries2.getEntries()[1]).toBe(measure);
   });
 
+  describe('observe()', () => {
+    it('rejects invalid entry type option combinations before registering with native', () => {
+      const callback = jest.fn();
+      const observer = new PerformanceObserver(callback);
+
+      // $FlowExpectedError[incompatible-call]
+      expect(() => observer.observe()).toThrow(
+        "Failed to execute 'observe' on 'PerformanceObserver': 1 argument required, but only 0 present.",
+      );
+      expect(() => observer.observe({})).toThrow(
+        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must include either entryTypes or type arguments.",
+      );
+      expect(() =>
+        observer.observe({entryTypes: ['mark'], type: 'measure'}),
+      ).toThrow(
+        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must not include both entryTypes and type arguments.",
+      );
+      expect(() =>
+        observer.observe({entryTypes: ['mark'], buffered: true}),
+      ).toThrow(
+        "Failed to execute 'observe' on 'PerformanceObserver': An observe() call must not include both entryTypes and buffered arguments.",
+      );
+    });
+  });
+
   describe('takeRecords()', () => {
     it('provides all buffered events and clears the buffer', () => {
       const callback = jest.fn();