karma.conf.babel.js

import puppeteerPkg from 'puppeteer/package.json'
import Downloader from 'puppeteer/utils/ChromiumDownloader'
import config from './config'
import webpackConfig from './webpack.config.babel'

const revision = puppeteerPkg.puppeteer.chromium_revision
const revisionInfo = Downloader.revisionInfo(Downloader.currentPlatform(), revision)

process.env.CHROME_BIN = revisionInfo.executablePath

const formatError = (msg) => {
  // filter out empty lines and node_modules
  if (!msg.trim() || /~/.test(msg)) return ''

  // indent the error beneath the it() message
  let newLine = `  ${msg}`

  if (newLine.includes('webpack:///')) {
    // remove webpack:///
    newLine = newLine.replace('webpack:///', '')

    // remove bundle location, showing only the source location
    newLine = newLine.slice(0, newLine.indexOf(' <- '))
  }

  return `${newLine}\n`
}

export default (karmaConfig) => {
  karmaConfig.set({
    basePath: process.cwd(),
    browsers: ['ChromeHeadless'],
    client: {
      mocha: {
        reporter: 'html', // change Karma's debug.html to mocha web reporter
        ui: 'bdd',
      },
    },
    coverageReporter: {
      reporters: [
        { type: 'lcov', dir: 'coverage', subdir: '.' },
        { type: 'text-summary' },
      ],
      includeAllSources: true,
    },
    customLaunchers: {
      puppeteer: {
        base: 'ChromeHeadless',
        flags: [
          // Avoid "Maximum call stack size exceeded" errors on CircleCI
          '--stack-trace-limit 50000',
        ],
      },
    },
    files: [
      './test/tests.bundle.js',
    ],
    formatError,
    frameworks: ['mocha'],
    reporters: ['mocha', 'coverage'],
    singleRun: true,
    preprocessors: {
      // do not include 'coverage' preprocessor for karma-coverage
      // code is already instrumented by babel-plugin-__coverage__
      './test/tests.bundle.js': ['webpack'],
    },
    webpack: {
      entry: './test/tests.bundle.js',
      externals: {
        ...webpackConfig.externals,
        // These are internal deps specific to React 0.13 required() by enzyme
        // They shouldn't be requiring these at all, issues and fix proposed
        // https://github.com/airbnb/enzyme/issues/285
        'react/lib/ExecutionEnvironment': true,
        'react/lib/ReactContext': true,
        // this is a React 0.13 dep required by enzyme
        // ignore it since we don't have it
        'react/addons': true,
      },
      devtool: config.compiler_devtool,
      module: webpackConfig.module,
      plugins: webpackConfig.plugins,
      resolve: webpackConfig.resolve,
    },
    webpackServer: {
      progress: false,
      stats: config.compiler_stats,
      debug: true,
      noInfo: false,
      quiet: false,
    },
  })
}