feat: suspense boundaries, streaming sidebar, N+1 fix for top-friends

- Backend: top-friends endpoint returns Vec<UserResponse> (JOIN already existed, handler was discarding data)
- Frontend: TopFriends self-contained — fetches own data via cookies, no more N+1 getUserProfile calls
- Frontend: sidebar (TopFriends, PopularTags, UsersCount) wrapped in Suspense — feed renders immediately
- Frontend: TagsSkeleton + CountSkeleton added to loading-skeleton.tsx
- Frontend: loading.tsx skeleton files added for feed, tags, search, and thread pages

crates/api-types/src/responses.rs

@@ -75,6 +75,12 @@ pub struct NotificationResponse {
     pub created_at: DateTime<Utc>,
 }
 
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct TopFriendsResponse {
+    pub top_friends: Vec<UserResponse>,
+}
+
 #[derive(Serialize, utoipa::ToSchema)]
 #[serde(rename_all = "camelCase")]
 pub struct ErrorResponse {

crates/presentation/src/handlers/social.rs

@@ -4,6 +4,8 @@ use crate::{
     state::AppState,
 };
 use api_types::requests::SetTopFriendsRequest;
+use api_types::responses::TopFriendsResponse;
+use crate::handlers::auth::to_user_response;
 use application::use_cases::profile::{get_top_friends, get_user_by_username, set_top_friends};
 use application::use_cases::social::*;
 use axum::{
@@ -155,15 +157,17 @@ pub async fn put_top_friends(
     set_top_friends(&*d.top_friends, &uid, ids).await?;
     Ok(StatusCode::NO_CONTENT)
 }
-#[utoipa::path(get, path = "/users/{username}/top-friends", params(("username" = String, Path, description = "Username")), responses((status = 200, description = "Top friends list")))]
+#[utoipa::path(get, path = "/users/{username}/top-friends",
+    params(("username" = String, Path, description = "Username")),
+    responses((status = 200, description = "Top friends list", body = TopFriendsResponse)))]
 pub async fn get_top_friends_handler(
     Deps(d): Deps<SocialDeps>,
     Path(username): Path<String>,
-) -> Result<Json<serde_json::Value>, ApiError> {
+) -> Result<Json<TopFriendsResponse>, ApiError> {
     let user = get_user_by_username(&*d.users, &username).await?;
     let friends = get_top_friends(&*d.top_friends, &user.id).await?;
-    let usernames: Vec<&str> = friends.iter().map(|(_, u)| u.username.as_str()).collect();
-    Ok(Json(serde_json::json!({ "topFriends": usernames })))
+    let top_friends = friends.iter().map(|(_, u)| to_user_response(u)).collect();
+    Ok(Json(TopFriendsResponse { top_friends }))
 }
 
 #[cfg(test)]

thoughts-frontend/app/loading.tsx

@@ -0,0 +1,20 @@
+import { ThoughtSkeleton } from "@/components/loading-skeleton";
+
+export default function FeedLoading() {
+  return (
+    <div className="container mx-auto max-w-6xl p-4 sm:p-6">
+      <div className="grid grid-cols-1 lg:grid-cols-4 gap-8">
+        <aside className="hidden lg:block lg:col-span-1" />
+        <main className="col-span-1 lg:col-span-2 space-y-6">
+          <div className="h-10 w-32 bg-muted rounded animate-pulse mb-6" />
+          <div className="space-y-4">
+            <ThoughtSkeleton />
+            <ThoughtSkeleton />
+            <ThoughtSkeleton />
+          </div>
+        </main>
+        <aside className="hidden lg:block lg:col-span-1" />
+      </div>
+    </div>
+  );
+}

thoughts-frontend/app/page.tsx

@@ -1,12 +1,6 @@
 import type { Metadata } from "next";
 import { cookies } from "next/headers";
-import {
-  getFeed,
-  getFriends,
-  getMe,
-  getTopFriends,
-  Me,
-} from "@/lib/api";
+import { getFeed, getMe, Me } from "@/lib/api";
 import { ThoughtForm } from "@/components/thought-form";
 import { EmptyState } from "@/components/empty-state";
 import { Button } from "@/components/ui/button";
@@ -16,9 +10,10 @@ import { ThoughtThread } from "@/components/thought-thread";
 import { buildThoughtThreads } from "@/lib/utils";
 import { TopFriends } from "@/components/top-friends";
 import { UsersCount } from "@/components/users-count";
-
 import { PaginationNav } from "@/components/pagination-nav";
 import { redirect } from "next/navigation";
+import { Suspense } from "react";
+import { ProfileSkeleton, TagsSkeleton, CountSkeleton } from "@/components/loading-skeleton";
 
 export const metadata: Metadata = {
   title: "Home",
@@ -61,18 +56,26 @@ async function FeedPage({
   const { items: allThoughts, totalPages } = feedData!;
   const thoughtThreads = buildThoughtThreads(allThoughts);
 
-  const friends = (await getFriends(token)).users.map((user) => user.username);
-  const topFriendsData = me
-    ? await getTopFriends(me.username, token).catch(() => ({ topFriends: [] }))
-    : { topFriends: [] };
-  const shouldDisplayTopFriends = topFriendsData.topFriends.length > 0;
+  const sidebar = (
+    <>
+      <Suspense fallback={<ProfileSkeleton />}>
+        <TopFriends username={me.username} />
+      </Suspense>
+      <Suspense fallback={<TagsSkeleton />}>
+        <PopularTags />
+      </Suspense>
+      <Suspense fallback={<CountSkeleton />}>
+        <UsersCount />
+      </Suspense>
+    </>
+  );
 
   return (
     <div className="container mx-auto max-w-6xl p-4 sm:p-6">
       <div className="grid grid-cols-1 lg:grid-cols-4 gap-8">
         <aside className="hidden lg:block lg:col-span-1">
           <div className="sticky top-20 space-y-6 glass-effect glossy-effect bottom rounded-md p-4">
-            <h2 className="text-lg font-semibold">Filters & Sorting</h2>
+            <h2 className="text-lg font-semibold">Filters &amp; Sorting</h2>
             <p className="text-sm text-muted-foreground">Coming soon...</p>
           </div>
         </aside>
@@ -84,14 +87,7 @@ async function FeedPage({
           <ThoughtForm />
 
           <div className="block lg:hidden space-y-6">
-            <PopularTags />
-            {shouldDisplayTopFriends && (
-              <TopFriends mode="top-friends" usernames={topFriendsData.topFriends} />
-            )}
-            {!shouldDisplayTopFriends && token && friends.length > 0 && (
-              <TopFriends mode="friends" usernames={friends || []} />
-            )}
-            <UsersCount />
+            {sidebar}
           </div>
 
           <div className="space-y-6">
@@ -115,14 +111,7 @@ async function FeedPage({
 
         <aside className="hidden lg:block lg:col-span-1">
           <div className="sticky top-20 space-y-6">
-            <PopularTags />
-            {shouldDisplayTopFriends && (
-              <TopFriends mode="top-friends" usernames={topFriendsData.topFriends} />
-            )}
-            {!shouldDisplayTopFriends && token && friends.length > 0 && (
-              <TopFriends mode="friends" usernames={friends || []} />
-            )}
-            <UsersCount />
+            {sidebar}
           </div>
         </aside>
       </div>

thoughts-frontend/app/search/loading.tsx

@@ -0,0 +1,12 @@
+import { ThoughtSkeleton } from "@/components/loading-skeleton";
+
+export default function SearchLoading() {
+  return (
+    <div className="container mx-auto max-w-2xl p-4 sm:p-6 space-y-4">
+      <div className="h-8 w-48 bg-muted rounded animate-pulse" />
+      <ThoughtSkeleton />
+      <ThoughtSkeleton />
+      <ThoughtSkeleton />
+    </div>
+  );
+}

thoughts-frontend/app/tags/[tagName]/loading.tsx

@@ -0,0 +1,12 @@
+import { ThoughtSkeleton } from "@/components/loading-skeleton";
+
+export default function TagLoading() {
+  return (
+    <div className="container mx-auto max-w-2xl p-4 sm:p-6 space-y-4">
+      <div className="h-8 w-40 bg-muted rounded animate-pulse" />
+      <ThoughtSkeleton />
+      <ThoughtSkeleton />
+      <ThoughtSkeleton />
+    </div>
+  );
+}

thoughts-frontend/app/thoughts/[thoughtId]/loading.tsx

@@ -0,0 +1,13 @@
+import { ThoughtSkeleton } from "@/components/loading-skeleton";
+
+export default function ThoughtLoading() {
+  return (
+    <div className="container mx-auto max-w-2xl p-4 sm:p-6 space-y-4">
+      <ThoughtSkeleton />
+      <div className="pl-6 border-l-2 border-primary border-dashed space-y-4">
+        <ThoughtSkeleton />
+        <ThoughtSkeleton />
+      </div>
+    </div>
+  );
+}

thoughts-frontend/app/users/[username]/page.tsx

@@ -5,7 +5,6 @@ import {
   getMe,
   getRemoteFollowers,
   getRemoteFollowing,
-  getTopFriends,
   getUserProfile,
   getUserThoughts,
   Me,
@@ -52,6 +51,8 @@ import { notFound } from "next/navigation";
 import { cookies } from "next/headers";
 import { FollowButton } from "@/components/follow-button";
 import { TopFriends } from "@/components/top-friends";
+import { Suspense } from "react";
+import { ProfileSkeleton } from "@/components/loading-skeleton";
 import { buildThoughtThreads } from "@/lib/utils";
 import { ThoughtThread } from "@/components/thought-thread";
 import { Button } from "@/components/ui/button";
@@ -127,15 +128,6 @@ export default async function ProfilePage({ params }: ProfilePageProps) {
   const fediverseHandle =
     user.local && apiDomain ? `@${user.username}@${apiDomain}` : null;
 
-  // Show who the profile owner follows (uses the already-fetched followingResult).
-  const friends =
-    followingResult.status === "fulfilled"
-      ? followingResult.value.items.map((u) => u.username)
-      : [];
-
-  const topFriendsData = await getTopFriends(username, token).catch(() => ({ topFriends: [] }));
-  const shouldDisplayTopFriends = topFriendsData.topFriends.length > 0;
-
   return (
     <div id={`profile-page-${user.username}`}>
       {user.customCss && (
@@ -252,10 +244,9 @@ export default async function ProfilePage({ params }: ProfilePageProps) {
               </div>
             </Card>
 
-            {shouldDisplayTopFriends && (
-              <TopFriends mode="top-friends" usernames={topFriendsData.topFriends} />
-            )}
-            {token && <TopFriends mode="friends" usernames={friends || []} />}
+            <Suspense fallback={<ProfileSkeleton />}>
+              <TopFriends username={user.username} />
+            </Suspense>
           </div>
         </aside>
 

thoughts-frontend/components/loading-skeleton.tsx

@@ -32,3 +32,26 @@ export function ProfileSkeleton() {
     </Card>
   )
 }
+
+export function TagsSkeleton() {
+  return (
+    <Card>
+      <CardContent className="pt-4 space-y-2">
+        <Skeleton className="h-4 w-24 mb-3" />
+        {[...Array(5)].map((_, i) => (
+          <Skeleton key={i} className="h-6 w-full rounded-full" />
+        ))}
+      </CardContent>
+    </Card>
+  )
+}
+
+export function CountSkeleton() {
+  return (
+    <Card>
+      <CardContent className="pt-4 pb-4">
+        <Skeleton className="h-6 w-32" />
+      </CardContent>
+    </Card>
+  )
+}

thoughts-frontend/components/top-friends.tsx

@@ -1,51 +1,25 @@
 import Link from "next/link";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 import { UserAvatar } from "./user-avatar";
-import { getUserProfile, User } from "@/lib/api";
+import { getTopFriends } from "@/lib/api";
 import { cookies } from "next/headers";
 
 interface TopFriendsProps {
-  mode: "friends" | "top-friends";
-  usernames: string[];
+  username: string;
 }
 
-export async function TopFriends({
-  mode = "top-friends",
-  usernames,
-}: TopFriendsProps) {
+export async function TopFriends({ username }: TopFriendsProps) {
   const token = (await cookies()).get("auth_token")?.value ?? null;
+  const data = await getTopFriends(username, token).catch(() => ({ topFriends: [] }));
+  const friends = data.topFriends;
 
-  if (usernames.length === 0) {
-    return (
-      <Card className="p-4">
-        <CardHeader className="p-0 pb-2">
-          <CardTitle className="text-lg text-shadow-md">Top Friends</CardTitle>
-        </CardHeader>
-        <CardContent className="p-0">
-          <p className="text-sm text-muted-foreground">
-            No top friends to display.
-          </p>
-        </CardContent>
-      </Card>
-    );
-  }
-
-  const friendsResults = await Promise.allSettled(
-    usernames.map((username) => getUserProfile(username, token))
-  );
-
-  const friends = friendsResults
-    .filter(
-      (result): result is PromiseFulfilledResult<User> =>
-        result.status === "fulfilled"
-    )
-    .map((result) => result.value);
+  if (friends.length === 0) return null;
 
   return (
     <Card id="top-friends" className="p-4">
       <CardHeader id="top-friends__header" className="p-0 pb-2">
         <CardTitle id="top-friends__title" className="text-lg text-shadow-md">
-          {mode === "top-friends" ? "Top Friends" : "Friends"}
+          Top Friends
         </CardTitle>
       </CardHeader>
       <CardContent id="top-friends__content" className="p-0">
@@ -59,7 +33,7 @@ export async function TopFriends({
             <UserAvatar src={friend.avatarUrl} alt={friend.username} />
             <span
               id={`top-friends__name-${friend.id}`}
-              className="text-xs truncate w-full group-hover:underline font-medium text-shadow-sm"
+              className="text-xs truncate w-full font-medium text-shadow-sm"
             >
               {friend.displayName || friend.username}
             </span>

thoughts-frontend/lib/api.ts

@@ -232,7 +232,7 @@ export const getTopFriends = (username: string, token: string | null) =>
   apiFetch(
     `/users/${username}/top-friends`,
     { next: { tags: [`profile:${username}`] } },
-    z.object({ topFriends: z.array(z.string()) }),
+    z.object({ topFriends: z.array(UserSchema) }),
     token
   );