webpack.config.js

const path = require('path');
const merge = require('webpack-merge');
const glob = require('glob');
const utils = require('./webpack.utils.js');
const webpack = require('webpack');
const WebpackMonitor = require('./plugin/npm-module/monitor');

const PATHS = {
  app: path.join(__dirname, 'client/index.jsx'),
  build: path.join(__dirname, 'build'),
};


module.exports = (env) => {
  const common = merge([
    {
      entry: {
        app: PATHS.app,
      },
      
      resolve: {
        extensions: ['.js', 'json', '.jsx'],
      },
      devServer: {
        historyApiFallback: true,
        contentBase: './build',
      },
      module: {
        rules: [
          {
            test: /.jsx?$/,
            loader: 'babel-loader',
            exclude: /node_modules/,
            query: {
              presets: ['es2015', 'react'],
            },
          },
          {
            test: /\.css$/,
            use: ['style-loader', 'css-loader'],
          },
          {
            test: /\.(png|svg|jpg|gif)$/,
            use: [
              'file-loader',
            ],
          },
        ],
        loaders: [
          {
            test: /\.json$/,
            loader: 'json-loader',
          },
        ],
      },
    },
    utils.purifyCSS({
      paths: glob.sync(`${PATHS.app}/**/*.js`, { nodir: true }),
    }),
  ]);

  const development = {
    output: {
      path: PATHS.build,
      filename: '[name].js',
    },
    plugins: [
      new webpack.DefinePlugin({ 'process.env.NODE_ENV': JSON.stringify('development') }),
    ],
  };

  const launch = merge([
    {
      output: {
        path: path.join(__dirname, 'plugin/npm-module/build'),
        filename: 'app.js',
      },
      plugins: [
        new webpack.DefinePlugin({ 'process.env.NODE_ENV': JSON.stringify('production') }),
        new WebpackMonitor({ launch: true, capture: false }),
      ],
    },
    utils.uglifyJS(),
  ]);

  const confirm = merge([
    {
      output: {
        path: path.join(__dirname, 'plugin/npm-module/build'),
        filename: 'app.js',
      },
      plugins: [
        new webpack.DefinePlugin({ 'process.env.NODE_ENV': JSON.stringify('data') }),
        new WebpackMonitor({ capture: true }),
      ],
    },
  ]);

  if (env === 'development') return merge([common, development]);
  if (env === 'confirm') return merge([common, confirm]);
  if (env === 'launch') return merge([common, launch]);
  return common;
};