karma-esnext-coverage-reporter

Unit test coverage reporter in Karma using esnext-coverage for ES6+.

Installation

npm install karma-esnext-coverage-reporter --save-dev

In addition to karma-esnext-coverage-reporter you will need babel-plugin-transform-esnext-coverage, a test framework like karma-mocha, and some esnext-coverage result formatters, like esnext-coverage-format-text.

Usage

In your karma configuration file declare the esnext-coverage reporter.

reporters: ['esnext-coverage']

Then specify the esnext-coverage reporter options. These options resemble the options of the karma-coverage plugin.

esnextCoverageReporter: {
  // Optional base directory of generated files:
  dir: 'reports/coverage',
  // List of formatters, where "formatter" indicates the
  // name of the formatter you want to use, for example "text"
  // will attempt to require "esnext-coverage-format-text"
  // which must be installed prior to running Karma:
  reporters: [
    {
      formatter: 'text', // indicates which formatter to use
      outFile: 'coverage.txt', // will write output to a file
      console: true // will write output to console
    }
  ],
  // Your code coverage thresholds:
  thresholds: {
    // Overall code coverage thresholds:
    global: {
      statement: 95,
      branch: 95,
      function: 95,
      line: 95
    },
    // Local (per-file) coverage thresholds:
    local: {
      statement: 50,
      branch: 50,
      function: 50,
      line: 50
    }
  }
}

Usage with karma-browserify

Follow the installation steps provided on karma-browserify usage page, then add a babelify transform with the following configuration. Change presets and plugins to match your needs, but try to keep the transform-esnext-coverage plugin the first in the list of babel transforms.

browserify: {
  transform: [
    ['babelify', {
      presets: ['es2015'],
      plugins: [
        ['transform-esnext-coverage', {only: '**/*.js'}]
      ]
    }]
  ]
},

Usage with .babelrc

Configure your .babelrc file with env options

{
  "env": {
    "test": {
      "plugins": [
        ["transform-esnext-coverage", {"only": "src/**/*.js"}]
      ]
    }
  }
}

Then set a BABEL_ENV option prior to running your tests.

BABEL_ENV=test YOUR_TEST_COMMAND_HERE

License

MIT License