test(tag): add testcase

components/tag/__tests__/index.test.tsx

@@ -0,0 +1,32 @@
+import React from 'react'
+import { mount, render } from 'enzyme'
+import { Tag } from 'components'
+
+describe('Tag', () => {
+  it('should render correctly', () => {
+    const wrapper = mount(<Tag>tag</Tag>)
+    expect(() => wrapper.unmount()).not.toThrow()
+  })
+  
+  it('should work with types', () => {
+    const wrapper = render(
+      <div>
+        <Tag type="success">success</Tag>
+        <Tag type="secondary">secondary</Tag>
+        <Tag type="error">error</Tag>
+        <Tag type="dark">dark</Tag>
+      </div>
+    )
+    expect(wrapper).toMatchSnapshot()
+  })
+  
+  it('should work with invert', () => {
+    const wrapper = render(<Tag type="success" invert>success</Tag>)
+    expect(wrapper).toMatchSnapshot()
+  })
+  
+  it('should work when child is null', () => {
+    const wrapper = mount(<Tag />)
+    expect(() => wrapper.unmount()).not.toThrow()
+  })
+})