From 8a87982d4b88be5824e61a2fa32d588289bbc806 Mon Sep 17 00:00:00 2001
From: Philipp Melab <philipp.melab@gmail.com>
Date: Mon, 3 Feb 2025 09:47:19 +0100
Subject: [PATCH] feat: make client router support view transitions

---
 packages/waku/src/router/client.ts | 67 ++++++++++++++++++++----------
 1 file changed, 46 insertions(+), 21 deletions(-)

diff --git a/packages/waku/src/router/client.ts b/packages/waku/src/router/client.ts
index 09a272408..61b9f939d 100644
--- a/packages/waku/src/router/client.ts
+++ b/packages/waku/src/router/client.ts
@@ -349,17 +349,25 @@ const InnerRouter = ({
   const changeRoute: ChangeRoute = useCallback(
     (route, options) => {
       const { skipRefetch } = options || {};
-      startTransition(() => {
-        if (!staticPathSet.has(route.path) && !skipRefetch) {
-          const rscPath = encodeRoutePath(route.path);
-          const rscParams = createRscParams(route.query);
-          refetch(rscPath, rscParams);
-        }
-        if (options.shouldScroll) {
-          handleScroll();
-        }
-        setRoute(route);
-      });
+      const performChange = () => {
+        startTransition(() => {
+          if (!staticPathSet.has(route.path) && !skipRefetch) {
+            const rscPath = encodeRoutePath(route.path);
+            const rscParams = createRscParams(route.query);
+            refetch(rscPath, rscParams);
+          }
+          if (options.shouldScroll) {
+            handleScroll();
+          }
+          setRoute(route);
+        });
+      };
+
+      if ('startViewTransition' in document && !skipRefetch) {
+        document.startViewTransition(performChange);
+      } else {
+        performChange();
+      }
     },
     [refetch, staticPathSet],
   );
@@ -380,7 +388,13 @@ const InnerRouter = ({
   useEffect(() => {
     const callback = () => {
       const route = parseRoute(new URL(window.location.href));
-      changeRoute(route, { shouldScroll: true });
+      if ('startViewTransition' in document) {
+        (document as any).startViewTransition(() => {
+          changeRoute(route, { shouldScroll: true });
+        });
+      } else {
+        changeRoute(route, { shouldScroll: true });
+      }
     };
     window.addEventListener('popstate', callback);
     return () => {
@@ -395,16 +409,27 @@ const InnerRouter = ({
       url.search = query;
       url.hash = '';
       if (path !== '/404') {
-        window.history.pushState(
-          {
-            ...window.history.state,
-            waku_new_path: url.pathname !== window.location.pathname,
-          },
-          '',
-          url,
-        );
+        const performNavigation = () => {
+          window.history.pushState(
+            {
+              ...window.history.state,
+              waku_new_path: url.pathname !== window.location.pathname,
+            },
+            '',
+            url,
+          );
+          changeRoute(parseRoute(url), {
+            skipRefetch: true,
+            shouldScroll: false,
+          });
+        };
+
+        if ('startViewTransition' in document) {
+          (document as any).startViewTransition(performNavigation);
+        } else {
+          performNavigation();
+        }
       }
-      changeRoute(parseRoute(url), { skipRefetch: true, shouldScroll: false });
     };
     locationListeners.add(callback);
     return () => {