webpack.test.config.js

const webpack = require('webpack');
const nodeExternals = require('webpack-node-externals');

module.exports = {
  target: 'node', // in order to ignore built-in modules like path, fs, etc.
  externals: [nodeExternals()], // in order to ignore all modules in node_modules folder
  plugins: [
    new webpack.DefinePlugin({
      ENV: '"test"',
      'process.env': {
        NODE_ENV: JSON.stringify('test'),
      }
    })
  ],
  module: {
    loaders: [
      {
        test: /\.jsx?$/,
        exclude: /node_modules/,
        loader: 'babel-loader'
      },
      {
        test: /\.(ttf|eot|svg|woff)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
        loader: 'file-loader'
      },
      {
        test: /\.less$/,
        loader: 'style-loader!css-loader!less-loader'
      }, {
        test: /\.css$/,
        loader: 'style-loader!css-loader'
      },
      {
        test: /\.json$/,
        loader: 'json-loader'
      },
      {
        test: /\.(png|jpg)$/,
        loader: 'url-loader?limit=8192'
      }
    ]
  }
};