From 6944d4a5338e77d379a00a949d359ac96efe76bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Magnus=20M=C3=BCller?=
 <67061560+MagMueller@users.noreply.github.com>
Date: Sun, 5 Oct 2025 20:36:23 -0700
Subject: [PATCH] Null checks

---
 browser_use/tools/service.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/browser_use/tools/service.py b/browser_use/tools/service.py
index 2851da352..07fee4f06 100644
--- a/browser_use/tools/service.py
+++ b/browser_use/tools/service.py
@@ -960,7 +960,7 @@ You will be given a query and the markdown of a webpage that has been filtered t
 			)
 
 		@self.registry.action(
-			"""Execute JS. MUST: wrap in IIFE (function(){...})() or (async function(){...})(), add try-catch, validate elements exist. Use for: hover, drag, custom selectors, forms, extract/filter links, iframes, shadow DOM, React/Vue/Angular. Limit output. Examples: (function(){try{const el=document.querySelector('#id');return el?el.value:'not found'}catch(e){return 'Error: '+e.message}})() ✓ | document.querySelector('#id').value ✗. Shadow: iterate hosts, check shadowRoot. Return JSON.stringify() for objects. Do not use comments""",
+			"""Execute JS. MUST: wrap in IIFE (function(){...})() or (async function(){...})(), add try-catch, validate elements exist. Check null before accessing properties. Use for: hover, drag, custom selectors, forms, extract/filter links, iframes, shadow DOM, React/Vue/Angular. Limit output. Examples: (function(){try{const el=document.querySelector('#id');return el?el.value:'not found'}catch(e){return 'Error: '+e.message}})() ✓ | document.querySelector('#id').value ✗. Shadow: iterate hosts, check shadowRoot. Return JSON.stringify() for objects. Do not use comments""",
 		)
 		async def evaluate(code: str, browser_session: BrowserSession):
 			# Execute JavaScript with proper error handling and promise support