feat: use vitest for testing

test/component.test.ts

@@ -0,0 +1,22 @@
+import { mount } from '@vue/test-utils'
+import { describe, it, expect } from 'vitest'
+import Counter from '../src/components/Counter.vue'
+
+describe('Counter.vue', () => {
+  it('should render', () => {
+    const wrapper = mount(Counter, { props: { initial: 10 } })
+    expect(wrapper.text()).toContain('10')
+    expect(wrapper.html()).toMatchSnapshot()
+  })
+
+  it('should be interactive', async() => {
+    const wrapper = mount(Counter, { props: { initial: 0 } })
+    expect(wrapper.text()).toContain('0')
+
+    expect(wrapper.find('.inc').exists()).toBe(true)
+
+    await wrapper.get('button').trigger('click')
+
+    expect(wrapper.text()).toContain('1')
+  })
+})