karma.conf.js

const webpack = require('webpack');

const {TEST_BROWSER} = process.env;
const runOnNode = TEST_BROWSER === 'ChromeHeadless';

module.exports = function (config) {
    config.set({
        browsers: [TEST_BROWSER || 'Chrome'],
        singleRun: runOnNode,
        frameworks: ['jasmine'],
        files: [
            './test/**/*.spec.js'
        ],
        reporters: [runOnNode ? 'spec' : 'kjhtml'],
        preprocessors: {
          './test/**/*.js': [ 'webpack','sourcemap'] //preprocess with webpack
        },
        webpack: {
            module: {
                loaders: [
                    {test: /\.js$/, exclude: /node_modules/, loaders: ['babel']},
                    {test: /\.json$/, loaders: ['json-loader']}
                ]
            },
            externals: {
            },
            watch: true
        },
        webpackServer: {
            noInfo: true
        }
    });
};