From dfe743c66056e217f5de8e4c7cec22620739f0bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Lorber?= <slorber@users.noreply.github.com>
Date: Thu, 5 May 2022 13:39:10 +0200
Subject: [PATCH] fix: avoid flash of page scrolling to top on refresh (#7342)

---
 .../src/client/ClientLifecyclesDispatcher.tsx | 20 ++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/packages/docusaurus/src/client/ClientLifecyclesDispatcher.tsx b/packages/docusaurus/src/client/ClientLifecyclesDispatcher.tsx
index 7c797af092d7..caf75a1647bf 100644
--- a/packages/docusaurus/src/client/ClientLifecyclesDispatcher.tsx
+++ b/packages/docusaurus/src/client/ClientLifecyclesDispatcher.tsx
@@ -27,6 +27,17 @@ export function dispatchLifecycleAction<K extends keyof ClientModule>(
   return () => callbacks.forEach((cb) => cb?.());
 }
 
+function scrollAfterNavigation(location: Location) {
+  const {hash} = location;
+  if (!hash) {
+    window.scrollTo(0, 0);
+  } else {
+    const id = decodeURIComponent(hash.substring(1));
+    const element = document.getElementById(id);
+    element?.scrollIntoView();
+  }
+}
+
 function ClientLifecyclesDispatcher({
   children,
   location,
@@ -38,13 +49,8 @@ function ClientLifecyclesDispatcher({
 }): JSX.Element {
   useLayoutEffect(() => {
     if (previousLocation !== location) {
-      const {hash} = location;
-      if (!hash) {
-        window.scrollTo(0, 0);
-      } else {
-        const id = decodeURIComponent(hash.substring(1));
-        const element = document.getElementById(id);
-        element?.scrollIntoView();
+      if (previousLocation) {
+        scrollAfterNavigation(location);
       }
       dispatchLifecycleAction('onRouteDidUpdate', {previousLocation, location});
     }