chore: add batch test

Author: schiller-manuel

packages/store/tests/batch.test.ts

@@ -0,0 +1,20 @@
+import { describe, expect, test } from 'vitest'
+import { Store } from '../src/store'
+import { batch } from '../src'
+
+describe('batch', () => {
+  test('updates store immediately', () => {
+    const store = new Store({ hello: 100, world: 200 })
+    batch(() => {
+      store.setState((state) => ({ ...state, hello: state.hello + 1 }))
+      expect(store.state.hello).toBe(101)
+      expect(store.state.world).toBe(200)
+      store.setState((state) => ({ ...state, world: state.world + 1 }))
+      expect(store.state.hello).toBe(101)
+      expect(store.state.world).toBe(201)
+    })
+
+    expect(store.state.hello).toBe(101)
+    expect(store.state.world).toBe(201)
+  })
+})