Karma + Mocha + Webpack

karma.conf.js

var webpack = require('webpack');

module.exports = function (config) {
  config.set({
    browsers: [ 'PhantomJS' ], //run in Phantom
    autoWatch: false,
    singleRun: true, //just run once by default
    frameworks: [ 'mocha', 'chai', 'sinon', 'chai-sinon' ], // test frameworks
    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    files: [
      'tests.webpack.js' //just load this file
    ],
    preprocessors: {
      'tests.webpack.js': [ 'webpack', 'sourcemap' ] //preprocess with webpack and our sourcemap loader
    },
    reporters: [ 'mocha' ], //report results in this format
    webpack: {
      devtool: 'inline-source-map',
      module: {
        loaders: [
          { test: /\.js$/, loader: 'babel-loader' }
        ]
      }
    },
    webpackServer: {
      noInfo: true
    },
    plugins: [
        'karma-mocha',
        'karma-webpack',
        'karma-sourcemap-loader',
        'karma-mocha-reporter',
        'karma-phantomjs-launcher',
        'karma-chai',
        'karma-sinon',
        'karma-chai-sinon'
    ]
  });
};

package.json

{
  "name": "test",
  "version": "1.0.0",
  "description": "Why you no work?",
  "main": "index.js",
  "scripts": {
    "test-karma": "./node_modules/.bin/karma start ./karma.conf.js",
    "start": "webpack --watch",
    "build": "webpack"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
  },
  "devDependencies": {
    "babel-core": "^6.9.1",
    "babel-loader": "^6.2.4",
    "babel-plugin-module-alias": "^1.5.0",
    "babel-preset-es2015": "^6.9.0",
    "bundle-loader": "^0.5.4",
    "chai": "^3.5.0",
    "css-loader": "^0.23.1",
    "karma": "^1.0.0",
    "karma-chai": "^0.1.0",
    "karma-chai-sinon": "^0.1.5",
    "karma-chrome-launcher": "^1.0.1",
    "karma-mocha": "^1.0.1",
    "karma-mocha-reporter": "^2.0.4",
    "karma-phantomjs-launcher": "^1.0.1",
    "karma-sinon": "^1.0.5",
    "karma-sourcemap-loader": "^0.3.7",
    "karma-webpack": "^1.7.0",
    "mocha": "^2.5.3",
    "phantomjs": "^2.1.7",
    "phantomjs-polyfill": "0.0.2",
    "sinon": "^1.17.4",
    "sinon-chai": "^2.8.0",
    "webpack": "^1.13.1"
  }
}

tests.webpack.js

// My initial intention was to have this file require all the rest of the test files as described here:
// https://www.codementor.io/reactjs/tutorial/test-reactjs-components-karma-webpack but for now I am treating it just
// as an individual test file

import chai from 'chai';
var expect = chai.expect;

console.log('I am running'); // don't even have this output in the console

describe('basic', function (){

  it('works', function () {
    expect(true).to.equal(true);
  });
  
});