fix the storage issue

src/ts/background/entity/stack.ts

@@ -58,7 +58,7 @@ export class Stack<T extends Stringifible> {
   private async _sync(): Promise<void> {
     try {
       const store = await this._storage.get(this._storageKey);
-      if (store.version < this._version) {
+      if (!store.version || store.version < this._version) {
         await this._storage.set(this._storageKey, new StackInHouse<T>(this._version, this._stack));
       } else if (store.version > this._version) {
         console.log('[DEBUG] lost memory data, recovering from storage', this._version, '->', store.version);

src/ts/background/repo/storage.ts

@@ -2,14 +2,10 @@ const { tabs, storage, commands, windows } = chrome;
 
 export class Storage<T> {
   get(key: string): Promise<T> {
-    return new Promise<T>((resolve) => {
-      storage.local.get(key, (value) => resolve(value as T));
-    });
+    return storage.local.get([key]).then(data => data[key] as T);
   }
 
   set(key: string, value: T): Promise<void> {
-    return new Promise<void>((resolve => {
-      storage.local.set({ [key]: value }, resolve);
-    }));
+    return storage.local.set({ [key]: value });
   }
 }