webpack.config.js

const path = require('path');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

module.exports = {
  entry: './src/index.js',
  output: {
    filename: 'index.js',
    path: path.resolve(__dirname, 'dist')
  },
  plugins: [
    new CleanWebpackPlugin(['dist'])
  ],
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: [
              [
                '@babel/preset-env', {
                  'targets': {
                    'browsers': [
                      '>0.25%',
                      'not ie 11',
                      'not op_mini all'
                    ]
                  }
                }
              ]
            ]
          }
        }
      },
      {
        test: /\.css$/,
        use: [ 'style-loader', 'css-loader' ]
      }
    ]
  }
};