From 51821488678348b3dbf4f7860501dbbc1eebf1f5 Mon Sep 17 00:00:00 2001
From: khalilcodes <khalilali.j@gmail.com>
Date: Mon, 20 Jun 2022 20:17:35 +0300
Subject: [PATCH] [site/toc][s]: fix headings observer for null values

---
 site/components/Heading.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/site/components/Heading.js b/site/components/Heading.js
index 189922e..f33b8ed 100644
--- a/site/components/Heading.js
+++ b/site/components/Heading.js
@@ -8,7 +8,8 @@ export const Heading = ({ level, observer }) => (props) => {
     if (!observer) {
       return
     }
-    observer.observe(document.getElementById(props.id));
+    const heading = document.getElementById(props.id)
+    if (heading) observer.observe(heading);
   });
 
   return React.createElement(`h${level}`, {