.babelrc

{
  "presets": ["crowdlab"],
  "env": {
    "test": {
      "plugins": [
        ["babel-plugin-webpack-loaders", {
          "config": "${WEBPACK_CONFIG_PATH}",
          "verbose": false
        }]
      ]
    }
  }
}

package.json

{ 
  ...
  "ava": {
    "files": [
      "src/**/*.test.js"
    ],
    "babel": "inherit",
    "require": [
      "babel-register",
      "../../tools/scripts/tests/setup-browser-env.js"
    ]
  }
}

run_tests.js

const chalk = require('chalk');
const path = require('path');
const shell = require('shelljs');

process.env.BABEL_DISABLE_CACHE = 1;
process.env.NODE_ENV = 'test';
process.env.WEBPACK_CONFIG_PATH = path.resolve(
  __dirname,
  'ava.webpack.config.js'
);

const runTests = ({ sourcePath = shell.pwd(), watch = false } = {}) => {
  const module = path.basename(sourcePath.toString());

  shell.cd(sourcePath);
  shell.echo(chalk.cyan(`Testing ${module}...`));
  shell.exec(`../../node_modules/.bin/ava -c 5 ${watch ? '--watch' : ''}`);
  shell.echo('');
  shell.echo(chalk.green(`Finished testing ${module}`));
};

module.exports = runTests;