Vue2单元测试覆盖率统计异常 与Vue3表现不一致

问题现象 #

• 参照Vue Test Utils v1官方安装指引完成单元测试环境搭建后，测试用例可正常执行
• 覆盖率统计结果异常：仅代码首行显示覆盖率标记，其余代码行均无覆盖率统计标记，无法正确展示全量代码覆盖情况
• 相同搭建逻辑在Vue 3项目中覆盖率统计可正常工作，问题仅出现在Vue 2项目

正常运行的Vue 3项目配置 #

package.json配置 #

{
  "name": "vue_three_without_ts",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "serve": "vue-cli-service serve",
    "build": "vue-cli-service build",
    "test:unit": "vue-cli-service test:unit",
    "lint": "vue-cli-service lint"
  },
  "dependencies": {
    "core-js": "^3.8.3",
    "vue": "^3.2.13"
  },
  "devDependencies": {
    "@babel/core": "^7.12.16",
    "@babel/eslint-parser": "^7.12.16",
    "@vue/cli-plugin-babel": "~5.0.0",
    "@vue/cli-plugin-eslint": "~5.0.0",
    "@vue/cli-plugin-unit-jest": "~5.0.0",
    "@vue/cli-service": "~5.0.0",
    "@vue/test-utils": "^2.0.0-0",
    "@vue/vue3-jest": "^27.0.0-alpha.1",
    "babel-jest": "^27.0.6",
    "eslint": "^7.32.0",
    "eslint-plugin-vue": "^8.0.3",
    "jest": "^27.0.5"
  }
}

Vue 3项目覆盖率正常运行效果 #

存在异常的Vue 2项目配置 #

package.json配置 #

{
  "name": "vue_two_without_ts",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "serve": "vue-cli-service serve",
    "build": "vue-cli-service build",
    "test:unit": "vue-cli-service test:unit",
    "lint": "vue-cli-service lint"
  },
  "dependencies": {
    "core-js": "^3.8.3",
    "vue": "^2.6.14"
  },
  "devDependencies": {
    "@babel/core": "^7.12.16",
    "@babel/eslint-parser": "^7.12.16",
    "@vue/cli-plugin-babel": "~5.0.0",
    "@vue/cli-plugin-eslint": "~5.0.0",
    "@vue/cli-plugin-unit-jest": "~5.0.0",
    "@vue/cli-service": "~5.0.0",
    "@vue/test-utils": "^1.1.3",
    "@vue/vue2-jest": "^27.0.0-alpha.2",
    "babel-jest": "^27.0.6",
    "eslint": "^7.32.0",
    "eslint-plugin-vue": "^8.0.3",
    "jest": "^27.0.5",
    "vue-template-compiler": "^2.6.14"
  }
}

Vue 2项目覆盖率异常运行效果 #

内容的提问来源于stack exchange，提问作者Amardeep1990