From 2ec92ac6733e6a4bfebb584f3c68c135b63d1aed Mon Sep 17 00:00:00 2001
From: Gim <gimholg1992@foxmail.com>
Date: Fri, 5 Aug 2022 12:15:36 +0800
Subject: [PATCH] fix: side-effect handling

---
 src/Viewer.tsx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Viewer.tsx b/src/Viewer.tsx
index 34a38db16..1ffe7bab1 100644
--- a/src/Viewer.tsx
+++ b/src/Viewer.tsx
@@ -9,7 +9,8 @@ export default (props: ViewerProps) => {
   const [ init, setInit ] = React.useState(false);
 
   React.useEffect(() => {
-    document.body.appendChild(defaultContainer.current);
+    document.body.appendChild(defaultContainer.current); // side-effect needs to be handled.
+    return ()=>{document.body.removeChild(defaultContainer.current);} // side-effect handling
   }, []);
 
   React.useEffect(() => {