karma.conf.js

const puppeteer = require('puppeteer');

process.env.CHROME_BIN = puppeteer.executablePath();

module.exports = config => {
  config.set({
    browsers: ['ChromeHeadless'],

    frameworks: ['mocha'],

    files: [
      { pattern: 'build/tests.bundle.js', watched: false },
    ],

    reporters: ['dots'],
  });
};