istanbul-instrumenter-loader

使用 istanbul-lib-instrument 将仪器 JS 文件用于随后的代码覆盖率报告

安装

npm i -D istanbul-instrumenter-loader

用法

• karma-webpack

• karma-coverage-istanbul-reporter

结构

├─ src
│ |– components
│ | |– bar
│ | │ |─ index.js
│ | |– foo/
│     |– index.js
|– test
| |– src
| | |– components
| | | |– foo
| | | | |– index.js

为生成所有组件（包括你没写测试的那些）的代码覆盖率报告，你需要 require 所有业务和测试的代码。相关内容在 karma-webpack 其他用法中有涉及

test/index.js

// requires all tests in `project/test/src/components/**/index.js`
const tests = require.context('./src/components/', true, /index\.js$/);

tests.keys().forEach(tests);

// requires all components in `project/src/components/**/index.js`
const components = require.context('../src/components/', true, /index\.js$/);

components.keys().forEach(components);

ℹ️以下为 karma 的唯一入口起点文件

karma.conf.js

config.set({
  ...
  files: [
    'test/index.js'
  ],
  preprocessors: {
    'test/index.js': 'webpack'
  },
  webpack: {
    ...
    module: {
      rules: [
        // instrument only testing sources with Istanbul
        {
          test: /\.js$/,
          use: { loader: 'istanbul-instrumenter-loader' },
          include: path.resolve('src/components/')
        }
      ]
    }
    ...
  },
  reporters: [ 'progress', 'coverage-istanbul' ],
  coverageIstanbulReporter: {
    reports: [ 'text-summary' ],
    fixWebpackSourcePaths: true
  }
  ...
});

使用 Babel

您必须将该检测作为后续步骤运行

webpack.config.js

{
  test: /\.js$|\.jsx$/,
  use: {
    loader: 'istanbul-instrumenter-loader',
    options: { esModules: true }
  },
  enforce: 'post',
  exclude: /node_modules|\.spec\.js$/,
}

选项

此 loader 支持 istanbul-lib-instrument 的所有配置选项

webpack.config.js

{
  test: /\.js$/,
  use: {
    loader: 'istanbul-instrumenter-loader',
    options: {...options}
  }
}