feat(hooks): add useState hook

src/__tests__/useState.test.ts

@@ -0,0 +1,24 @@
+import useState from '../useState';
+import renderHook from '../util/renderHook';
+
+describe('useState', () => {
+  it('should be defined', () => {
+    expect(useState).toBeDefined();
+  });
+
+  it('should update state', () => {
+    type Inject = { count1: number; count2: number };
+    const { vm } = renderHook<Inject>(() => ({
+      ...useState({ count1: 'count' }),
+      ...useState('test', { count2: 'count' }),
+    }));
+    expect(vm.count1).toBe(0);
+    expect(vm.count2).toBe(0);
+
+    vm.$store.commit('increment');
+    vm.$store.commit('test/decrement');
+
+    expect(vm.count1).toBe(1);
+    expect(vm.count2).toBe(-1);
+  });
+});

src/useState.ts

@@ -0,0 +1,3 @@
+import createVuexHelper, { Helper } from './util/helpers';
+
+export default createVuexHelper(Helper.State);