fix: #1005 fixed, by updating type-definations to getItem method. (#1007)

Co-authored-by: Aaron <aaronklinker1@gmail.com>

packages/wxt/src/__tests__/storage.test.ts

@@ -903,5 +903,24 @@ describe('Storage Utils', () => {
       // @ts-expect-error
       await storage.getItem('loca:test').catch(() => {});
     });
+
+    it('should return a nullable type when getItem is called without a fallback', async () => {
+      const res = await storage.getItem<string>('local:test');
+      expectTypeOf(res).toBeNullable();
+    });
+
+    it('should return a non-null type when getItem is called with a fallback', async () => {
+      const res = await storage.getItem('local:test', {
+        fallback: 'test',
+      });
+      expectTypeOf(res).not.toBeNullable();
+    });
+
+    it('should return a non-null type when getItem is called with a fallback and the first type parameter is passed', async () => {
+      const res = await storage.getItem<string>('local:test', {
+        fallback: 'test',
+      });
+      expectTypeOf(res).not.toBeNullable();
+    });
   });
 });

packages/wxt/src/storage.ts

@@ -461,7 +461,16 @@ export interface WxtStorage {
    * @example
    * await storage.getItem<number>("local:installDate");
    */
-  getItem<T>(key: StorageItemKey, opts?: GetItemOptions<T>): Promise<T | null>;
+  getItem<TValue>(
+    key: StorageItemKey,
+    opts: GetItemOptions<TValue> & { fallback: TValue },
+  ): Promise<TValue>;
+
+  getItem<TValue>(
+    key: StorageItemKey,
+    opts?: GetItemOptions<TValue>,
+  ): Promise<TValue | null>;
+
   /**
    * Get multiple items from storage. The return order is guaranteed to be the same as the order
    * requested.