chore: also add the new test files

test/plugin-server.test.js

@@ -0,0 +1,32 @@
+import { mount, defaultOptions, VueMetaServerPlugin, loadVueMetaPlugin } from './utils'
+
+jest.mock('../package.json', () => ({
+  version: 'test-version'
+}))
+
+describe('plugin', () => {
+  let Vue
+
+  beforeAll(() => (Vue = loadVueMetaPlugin()))
+
+  test('is loaded', () => {
+    const instance = new Vue()
+    expect(instance.$meta).toEqual(expect.any(Function))
+  })
+
+  test('component has _hasMetaInfo set to true', () => {
+    const Component = Vue.component('test-component', {
+      template: '<div>Test</div>',
+      [defaultOptions.keyName]: {
+        title: 'Hello World'
+      }
+    })
+
+    const { vm } = mount(Component, { localVue: Vue })
+    expect(vm._hasMetaInfo).toBe(true)
+  })
+
+  test('plugin sets package version', () => {
+    expect(VueMetaServerPlugin.version).toBe('test-version')
+  })
+})