vue3添加单元测试

用vite搭建的vue3项目没有带单元测试功能，后期想添加这功能，我的思路是用vue-cli搭建一个有单元测试的空框架，然后把单元测试需要的文件复制到项目中。如果项目中有TS，创建项目的时候就要把ts也一起创建。
需要复制的文件有：
1.readme

# jesttwo

## Project setup

npm install

### Compiles and hot-reloads for development

npm run serve

### Compiles and minifies for production

npm run build

### Run your unit tests

npm run test:unit

### Customize configuration
See [Configuration Reference](https://cli.vuejs.org/config/).

2.tsconfig.json

{
  "compilerOptions": {
    "target": "esnext",
    "module": "esnext",
    "strict": true,
    "jsx": "preserve",
    "importHelpers": true,
    "moduleResolution": "node",
    "experimentalDecorators": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "sourceMap": true,
    "baseUrl": ".",
    "types": [
      "webpack-env",
      "jest"
    ],
    "paths": {
      "@/*": [
        "src/*"
      ]
    },
    "lib": [
      "esnext",
      "dom",
      "dom.iterable",
      "scripthost"
    ]
  },
  "include": [
    "src/**/*.ts",
    "src/**/*.tsx",
    "src/**/*.vue",
    "tests/**/*.ts",
    "tests/**/*.tsx"
  ],
  "exclude": [
    "node_modules"
  ]
}

3.package.json

{
  "name": "jesttwo",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "serve": "vue-cli-service serve",
    "build": "vue-cli-service build",
    "test:unit": "vue-cli-service test:unit"
  },
  "dependencies": {
    "core-js": "^3.6.5",
    "vue": "^3.0.0",
    "vue-class-component": "^8.0.0-0"
  },
  "devDependencies": {
    "@types/jest": "^24.0.19",
    "@vue/cli-plugin-babel": "~4.5.0",
    "@vue/cli-plugin-typescript": "~4.5.0",
    "@vue/cli-plugin-unit-jest": "~4.5.0",
    "@vue/cli-service": "~4.5.0",
    "@vue/compiler-sfc": "^3.0.0",
    "@vue/test-utils": "^2.0.0-0",
    "typescript": "~4.1.5",
    "vue-jest": "^5.0.0-0"
  },
  "browserslist": [
    "> 1%",
    "last 2 versions",
    "not dead"
  ],
  "jest": {
    "preset": "@vue/cli-plugin-unit-jest/presets/typescript-and-babel",
    "transform": {
      "^.+\\.vue$": "vue-jest"
    }
  }
}

4.tests文件夹，与src文件夹平级
tests/unit/example.spec.ts

import { shallowMount } from '@vue/test-utils'
import HelloWorld from '@/components/HelloWorld.vue'

describe('HelloWorld.vue', () => {
  it('renders props.msg when passed', () => {
    const msg = 'new message'
    const wrapper = shallowMount(HelloWorld, {
      props: { msg }
    })
    expect(wrapper.text()).toMatch(msg)
  })
})

5.复制公共组件库中的HelloWorld.vue文件
src/components/HelloWorld.vue

<template>
  <div class="hello">
    <h1>{{ msg }}</h1>
    <p>
      For a guide and recipes on how to configure / customize this project,<br>
      check out the
      <a href="https://cli.vuejs.org" target="_blank" rel="noopener">vue-cli documentation</a>.
    </p>
    <h3>Installed CLI Plugins</h3>
    <ul>
      <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-babel" target="_blank" rel="noopener">babel</a></li>
      <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-typescript" target="_blank" rel="noopener">typescript</a></li>
      <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-unit-jest" target="_blank" rel="noopener">unit-jest</a></li>
    </ul>
    <h3>Essential Links</h3>
    <ul>
      <li><a href="https://vuejs.org" target="_blank" rel="noopener">Core Docs</a></li>
      <li><a href="https://forum.vuejs.org" target="_blank" rel="noopener">Forum</a></li>
      <li><a href="https://chat.vuejs.org" target="_blank" rel="noopener">Community Chat</a></li>
      <li><a href="https://twitter.com/vuejs" target="_blank" rel="noopener">Twitter</a></li>
      <li><a href="https://news.vuejs.org" target="_blank" rel="noopener">News</a></li>
    </ul>
    <h3>Ecosystem</h3>
    <ul>
      <li><a href="https://router.vuejs.org" target="_blank" rel="noopener">vue-router</a></li>
      <li><a href="https://vuex.vuejs.org" target="_blank" rel="noopener">vuex</a></li>
      <li><a href="https://github.com/vuejs/vue-devtools#vue-devtools" target="_blank" rel="noopener">vue-devtools</a></li>
      <li><a href="https://vue-loader.vuejs.org" target="_blank" rel="noopener">vue-loader</a></li>
      <li><a href="https://github.com/vuejs/awesome-vue" target="_blank" rel="noopener">awesome-vue</a></li>
    </ul>
  </div>
</template>

<script lang="ts">
import { Options, Vue } from 'vue-class-component';

@Options({
  props: {
    msg: String
  }
})
export default class HelloWorld extends Vue {
  msg!: string
}
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
h3 {
  margin: 40px 0 0;
}
ul {
  list-style-type: none;
  padding: 0;
}
li {
  display: inline-block;
  margin: 0 10px;
}
a {
  color: #42b983;
}
</style>