From d43c873dc92538993f8a1f89a5b8ea597fc62b08 Mon Sep 17 00:00:00 2001
From: Ilia Mashkov <hikkikomori7@gmail.com>
Date: Mon, 2 Feb 2026 11:57:00 +0300
Subject: [PATCH] feat(createPersistentStore): add a solution to keep user info
 between sections using browser storage

---
 .../createPersistentStore.svelte.ts           | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 src/shared/lib/helpers/createPersistentStore/createPersistentStore.svelte.ts

diff --git a/src/shared/lib/helpers/createPersistentStore/createPersistentStore.svelte.ts b/src/shared/lib/helpers/createPersistentStore/createPersistentStore.svelte.ts
new file mode 100644
index 0000000..cfb37ad
--- /dev/null
+++ b/src/shared/lib/helpers/createPersistentStore/createPersistentStore.svelte.ts
@@ -0,0 +1,51 @@
+/**
+ * Reusable persistent storage utility using Svelte 5 runes
+ *
+ * Automatically syncs state with localStorage.
+ */
+export function createPersistentStore<T>(key: string, defaultValue: T) {
+    // Initialize from storage or default
+    const loadFromStorage = (): T => {
+        if (typeof window === 'undefined') {
+            return defaultValue;
+        }
+        try {
+            const item = localStorage.getItem(key);
+            return item ? JSON.parse(item) : defaultValue;
+        } catch (error) {
+            console.warn(`[createPersistentStore] Error loading ${key}:`, error);
+            return defaultValue;
+        }
+    };
+
+    let value = $state<T>(loadFromStorage());
+
+    // Sync to storage whenever value changes
+    $effect.root(() => {
+        $effect(() => {
+            if (typeof window === 'undefined') {
+                return;
+            }
+            try {
+                localStorage.setItem(key, JSON.stringify(value));
+            } catch (error) {
+                console.warn(`[createPersistentStore] Error saving ${key}:`, error);
+            }
+        });
+    });
+
+    return {
+        get value() {
+            return value;
+        },
+        set value(v: T) {
+            value = v;
+        },
+        clear() {
+            if (typeof window !== 'undefined') {
+                localStorage.removeItem(key);
+            }
+            value = defaultValue;
+        },
+    };
+}