Coverage + tests with webpack, babel, karma, mocha, and istanbul

karma.conf.js

var webpack = require('webpack')

module.exports = function (config) {
  config.set({
    browsers: [ 'Chrome' ], //run in Chrome
    browserNoActivityTimeout: 60000,
    singleRun: true, //just run once by default
    frameworks: [ 'mocha' ], //use the mocha test framework
    files: [
      //'src/**/*.{jsx,js}',
      'tests.webpack.js' //just load this file
    ],
    preprocessors: {
      'tests.webpack.js': ['webpack', 'sourcemap' ], //preprocess with webpack and our sourcemap loader
      //'src/**/*.jsx?': ['coverage']
    },
    reporters: [ 'mocha', 'coverage' ], //report results in this format
    mochaReporter: {
      output: 'autowatch'
    },
    coverageReporter: {
      reporters: [
        {type: 'text'},
        {type: 'html'}
      ]
    },
    webpack: {
      devtool: 'inline-source-map',
      module: {
        loaders: [
          { test: /\.jsx?$/, loader: 'babel-loader' }
        ],
        postLoaders: [ {
          test: /\.js$/,
          exclude: /(test|node_modules|bower_components)\//,
            loader: 'istanbul-instrumenter'
        } ]
      }
    },
    webpackServer: {
      noInfo: true //please don't spam the console when running in karma!
    }
  });
};

tests.webpack.js

var context = require.context('./src', true, /\.test\.jsx?$/) // make sure you have your directory and regex test set correctly!
context.keys().forEach(context)