feat(sidebar): add smooth animations and persistent category collapse state

components/sidebar/CategorySection.tsx

@@ -1,17 +1,18 @@
 /**
  * @file components/sidebar/CategorySection.tsx
- * @description Sub-component for rendering a category group and its list of channels.
+ * @description Sub-component for rendering a category group and its list of channels with persistent collapse state and animations.
  */
 
 "use client";
 
-import { useState } from "react";
-import { ChevronDown, ChevronRight, Plus, Settings } from "lucide-react";
+import { ChevronDown, Plus, Settings } from "lucide-react";
+import { motion, AnimatePresence } from "framer-motion";
 import { ChannelItem } from "./ChannelItem";
 import type { Channel } from "@/db/schema";
+import { useLocalStorage } from "@/lib/hooks/useLocalStorage";
 
-/** Props for the CategorySection component. */
 interface CategorySectionProps {
+  id: string;
   title: string;
   channels: Channel[];
   currentChannelId: string;
@@ -22,8 +23,9 @@ interface CategorySectionProps {
   onEditCategory?: () => void;
 }
 
-/** Renders a collapsible category section containing channels and contextual actions. */
+/** Renders a collapsible category section with persistent collapse state and smooth animation. */
 export function CategorySection({
+  id,
   title,
   channels,
   currentChannelId,
@@ -33,23 +35,27 @@ export function CategorySection({
   onEditChannel,
   onEditCategory,
 }: CategorySectionProps) {
-  const [isCollapsed, setIsCollapsed] = useState(false);
+  const [isCollapsed, setIsCollapsed] = useLocalStorage(
+    `category_collapsed_${id}`,
+    false,
+  );
+
+  const toggleCollapsed = () => {
+    setIsCollapsed((prev) => !prev);
+  };
 
-  /** Handles closing mobile navigation when clicking a channel. */
   const handleChannelClick = () => {
     if (!window.matchMedia("(min-width: 768px)").matches) {
       onCloseNav();
     }
   };
 
-  /** Opens settings for a specific channel. */
   const handleOpenChannelSettings = (e: React.MouseEvent, channel: Channel) => {
     e.preventDefault();
     e.stopPropagation();
     onEditChannel(channel);
   };
 
-  /** Opens settings for the current category. */
   const handleOpenCategorySettings = (e: React.MouseEvent) => {
     e.preventDefault();
     e.stopPropagation();
@@ -61,14 +67,16 @@ export function CategorySection({
       <div className="flex items-center justify-between text-xs font-semibold text-muted px-1 py-1 uppercase tracking-wider group">
         <button
           type="button"
-          onClick={() => setIsCollapsed((prev) => !prev)}
+          onClick={toggleCollapsed}
           className="flex items-center gap-1 hover:text-white transition-colors cursor-pointer min-w-0 truncate"
         >
-          {isCollapsed ? (
-            <ChevronRight className="w-3.5 h-3.5 shrink-0" />
-          ) : (
-            <ChevronDown className="w-3.5 h-3.5 shrink-0" />
-          )}
+          <motion.div
+            animate={{ rotate: isCollapsed ? -90 : 0 }}
+            transition={{ duration: 0.15, ease: "easeInOut" }}
+            className="shrink-0"
+          >
+            <ChevronDown className="w-3.5 h-3.5" />
+          </motion.div>
           <span className="truncate">{title}</span>
         </button>
 
@@ -94,20 +102,28 @@ export function CategorySection({
         </div>
       </div>
 
-      {!isCollapsed && (
-        <div className="space-y-0.5 pl-2">
-          {channels.map((channel) => (
-            <ChannelItem
-              key={channel.id}
-              channel={channel}
-              serverId={serverId}
-              isActive={currentChannelId === channel.id}
-              onChannelClick={handleChannelClick}
-              onOpenSettings={handleOpenChannelSettings}
-            />
-          ))}
-        </div>
-      )}
+      <AnimatePresence initial={false}>
+        {!isCollapsed && (
+          <motion.div
+            initial={{ height: 0, opacity: 0 }}
+            animate={{ height: "auto", opacity: 1 }}
+            exit={{ height: 0, opacity: 0 }}
+            transition={{ duration: 0.2, ease: "easeInOut" }}
+            className="overflow-hidden space-y-0.5 pl-2"
+          >
+            {channels.map((channel) => (
+              <ChannelItem
+                key={channel.id}
+                channel={channel}
+                serverId={serverId}
+                isActive={currentChannelId === channel.id}
+                onChannelClick={handleChannelClick}
+                onOpenSettings={handleOpenChannelSettings}
+              />
+            ))}
+          </motion.div>
+        )}
+      </AnimatePresence>
     </div>
   );
 }

components/sidebar/ChannelSidebar.tsx

@@ -74,7 +74,9 @@ export function ChannelSidebar() {
 
         {/* Content */}
         <div className="flex-1 overflow-y-auto p-3 space-y-4 min-w-0">
+          {/* Uncategorized channels */}
           <CategorySection
+            id="uncategorized"
             title="Text Channels"
             channels={uncategorizedChannels}
             currentChannelId={currentChannelId}
@@ -84,9 +86,11 @@ export function ChannelSidebar() {
             onEditChannel={setEditingChannel}
           />
 
+          {/* Custom categories */}
           {categories.map((category) => (
             <CategorySection
               key={category.id}
+              id={category.id}
               title={category.name}
               channels={category.channels}
               currentChannelId={currentChannelId}

lib/hooks/useLocalStorage.ts

@@ -0,0 +1,38 @@
+/**
+ * @file lib/hooks/useLocalStorage.ts
+ * @description Custom React hook for synchronized state persistence with browser local storage.
+ */
+
+import { useState, useEffect } from "react";
+
+/** Custom hook that synchronizes a React state variable with local storage. */
+export function useLocalStorage<T>(key: string, initialValue: T) {
+  const [storedValue, setStoredValue] = useState<T>(initialValue);
+
+  /** Loads the stored value from local storage on initial mount or key change. */
+  useEffect(() => {
+    try {
+      const item = localStorage.getItem(key);
+      if (item !== null) {
+        setStoredValue(JSON.parse(item));
+      }
+    } catch (error) {
+      console.warn(`Error reading localStorage key "${key}":`, error);
+    }
+  }, [key]);
+
+  /** Updates the state and persists the new value to local storage. */
+  const setValue = (value: T | ((val: T) => T)) => {
+    try {
+      setStoredValue((prev) => {
+        const valueToStore = value instanceof Function ? value(prev) : value;
+        localStorage.setItem(key, JSON.stringify(valueToStore));
+        return valueToStore;
+      });
+    } catch (error) {
+      console.warn(`Error setting localStorage key "${key}":`, error);
+    }
+  };
+
+  return [storedValue, setValue] as const;
+}

package-lock.json

@@ -12,6 +12,7 @@
         "clsx": "^2.1.1",
         "dotenv": "^17.4.2",
         "drizzle-orm": "^0.45.2",
+        "framer-motion": "^13.3.0",
         "lucide-react": "^1.35.0",
         "next": "16.3.3",
         "next-auth": "^5.0.0-beta.32",
@@ -5041,6 +5042,29 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/framer-motion": {
+      "version": "13.3.0",
+      "resolved": "https://registry.npmjs.org/framer-motion/-/framer-motion-13.3.0.tgz",
+      "integrity": "sha512-nry9figMPgd/7tTy9zzGRsD+kJ9tjZ74sKJ3jFBa7j6DTBIM04T6eBgneFLXCB0151wychIxsiojPlcG4JxeoA==",
+      "license": "MIT",
+      "dependencies": {
+        "motion-dom": "^13.3.0",
+        "motion-utils": "^13.3.0",
+        "tslib": "^2.4.0"
+      },
+      "peerDependencies": {
+        "react": "^18.0.0 || ^19.0.0",
+        "react-dom": "^18.0.0 || ^19.0.0"
+      },
+      "peerDependenciesMeta": {
+        "react": {
+          "optional": true
+        },
+        "react-dom": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/fsevents": {
       "version": "2.3.3",
       "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.3.tgz",
@@ -6430,6 +6454,21 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/motion-dom": {
+      "version": "13.3.0",
+      "resolved": "https://registry.npmjs.org/motion-dom/-/motion-dom-13.3.0.tgz",
+      "integrity": "sha512-AmAnB6pHdZ1vHGzWzuzteG6Q3j1lHKeX/lbST6jGlgm0cjvLUgaCk1xhOuPMOy5SgovN6wnnUdwFrkcsus7Ftg==",
+      "license": "MIT",
+      "dependencies": {
+        "motion-utils": "^13.3.0"
+      }
+    },
+    "node_modules/motion-utils": {
+      "version": "13.3.0",
+      "resolved": "https://registry.npmjs.org/motion-utils/-/motion-utils-13.3.0.tgz",
+      "integrity": "sha512-sgSschQp7EseHInIlR7hBbMuvet3RA0bs28KPZAXJcGKGdxHGvh1ogpYDilY3bOMtl73EqPNmp75sAKHYPU5sg==",
+      "license": "MIT"
+    },
     "node_modules/ms": {
       "version": "2.1.3",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",

package.json

@@ -17,6 +17,7 @@
     "clsx": "^2.1.1",
     "dotenv": "^17.4.2",
     "drizzle-orm": "^0.45.2",
+    "framer-motion": "^13.3.0",
     "lucide-react": "^1.35.0",
     "next": "16.3.3",
     "next-auth": "^5.0.0-beta.32",