webpack.config.js

const path = require('path')
const CleanWebpackPlugin = require('clean-webpack-plugin')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const webpack = require('webpack')

const env = process.env.NODE_ENV || 'development'

module.exports = {
  mode: env,
  entry: {
    main: './src/main.js',
    'script-injector': './src/script-injector.js',
  },
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: '[name].bundle.js',
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
      },
    ],
  },
  devtool:
    env === 'production' ? undefined : 'cheap-module-eval-source-map',
  plugins: [
    new webpack.ProgressPlugin(),
    // clean the build folder
    new CleanWebpackPlugin(),
    // expose and write the allowed env vars on the compiled bundle
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify(env),
      'process.env.APP_NAME': JSON.stringify(
        process.env.npm_package_name,
      ),
      'process.env.DEBUG': JSON.stringify(process.env.DEBUG),
    }),
    new CopyWebpackPlugin([
      {
        from: 'manifest.json',
        transform: function(content, path) {
          // generates the manifest file using the package.json informations
          return Buffer.from(
            JSON.stringify({
              description: process.env.npm_package_description,
              version: process.env.npm_package_version,
              ...JSON.parse(content.toString()),
            }),
          )
        },
      },
    ]),
  ],
}