Fix updateTag in migrateChatUser by moving cache invalidation to a Server Action

app/accountMenu.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { authClient } from "@/lib/auth-client";
-import { usePathname } from "next/navigation";
+import { usePathname, useRouter } from "next/navigation";
 import { useEffect } from "react";
 
 export function AutoAnonymousLogin() {
@@ -18,6 +18,7 @@
 export function AccountMenu() {
   const { data: session, isPending } = authClient.useSession();
   const pathname = usePathname();
+  const router = useRouter();
 
   const signout = () => {
     if (
@@ -27,7 +28,7 @@
     ) {
       authClient.signOut({
         fetchOptions: {
-          onSuccess: () => window.location.reload(),
+          onSuccess: () => router.refresh(),
         },
       });
     }
@@ -36,7 +37,7 @@
     if (window.confirm("チャット履歴は削除され、アクセスできなくなります。")) {
       authClient.signOut({
         fetchOptions: {
-          onSuccess: () => window.location.reload(),
+          onSuccess: () => router.refresh(),
         },
       });
     }
@@ -51,7 +52,7 @@
       <div className="dropdown dropdown-end">
         <label tabIndex={0} className="btn btn-ghost btn-circle avatar">
           <div className="w-8 h-8 rounded-full">
             <img
               src={
                 session.user?.image ??
                 `https://avatar.vercel.sh/${session.user?.name}`
@@ -102,7 +103,7 @@
             onClick={() =>
               authClient.signIn.social({
                 provider: "github",
-                callbackURL: pathname,
+                callbackURL: `/clear-cache?redirect=${encodeURIComponent(pathname)}`,
               })
             }
           >
@@ -114,7 +115,7 @@
             onClick={() =>
               authClient.signIn.social({
                 provider: "google",
-                callbackURL: pathname,
+                callbackURL: `/clear-cache?redirect=${encodeURIComponent(pathname)}`,
               })
             }
           >

app/actions/clearUserCache.ts

@@ -0,0 +1,29 @@
+"use server";
+
+import { initContext, cacheKeyForPage } from "@/lib/chatHistory";
+import { updateTag } from "next/cache";
+import { getPagesList } from "@/lib/docs";
+import { isCloudflare } from "@/lib/detectCloudflare";
+
+export async function clearUserCacheAction() {
+  const ctx = await initContext();
+  if (!ctx.userId) return;
+
+  const pagesList = await getPagesList();
+  for (const lang of pagesList) {
+    for (const page of lang.pages) {
+      updateTag(cacheKeyForPage({ lang: lang.id, page: page.slug }, ctx.userId));
+    }
+  }
+
+  if (isCloudflare()) {
+    const cache = await caches.open("chatHistory");
+    for (const lang of pagesList) {
+      for (const page of lang.pages) {
+        await cache.delete(
+          cacheKeyForPage({ lang: lang.id, page: page.slug }, ctx.userId)
+        );
+      }
+    }
+  }
+}

app/clear-cache/page.tsx

@@ -0,0 +1,31 @@
+"use client";
+
+import { clearUserCacheAction } from "@/actions/clearUserCache";
+import { useRouter, useSearchParams } from "next/navigation";
+import { Suspense, useEffect } from "react";
+
+function ClearCacheContent() {
+  const router = useRouter();
+  const searchParams = useSearchParams();
+
+  useEffect(() => {
+    const redirectParam = searchParams.get("redirect") ?? "/";
+    // Only allow relative redirects to prevent open redirect attacks
+    const redirect = redirectParam.startsWith("/") ? redirectParam : "/";
+    clearUserCacheAction()
+      .catch(() => {})
+      .finally(() => {
+        router.replace(redirect);
+      });
+  }, [router, searchParams]);
+
+  return null;
+}
+
+export default function ClearCachePage() {
+  return (
+    <Suspense>
+      <ClearCacheContent />
+    </Suspense>
+  );
+}

app/lib/chatHistory.ts

@@ -6,7 +6,7 @@ import { and, asc, eq, exists } from "drizzle-orm";
 import { Auth } from "better-auth";
 import { updateTag } from "next/cache";
 import { isCloudflare } from "./detectCloudflare";
-import { getPagesList, LangId, PagePath, PageSlug, SectionId } from "./docs";
+import { LangId, PagePath, PageSlug, SectionId } from "./docs";
 
 export interface CreateChatMessage {
   role: "user" | "ai" | "error";
@@ -279,22 +279,4 @@ export async function migrateChatUser(oldUserId: string, newUserId: string) {
     .update(chat)
     .set({ userId: newUserId })
     .where(eq(chat.userId, oldUserId));
-  const pagesList = await getPagesList();
-  for (const lang of pagesList) {
-    for (const page of lang.pages) {
-      updateTag(
-        cacheKeyForPage({ lang: lang.id, page: page.slug }, newUserId)
-      );
-    }
-  }
-  if (isCloudflare()) {
-    const cache = await caches.open("chatHistory");
-    for (const lang of pagesList) {
-      for (const page of lang.pages) {
-        await cache.delete(
-          cacheKeyForPage({ lang: lang.id, page: page.slug }, newUserId)
-        );
-      }
-    }
-  }
 }