webpack.config.js

const path = require('path');
const CopyPlugin = require('copy-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  mode: 'production',
  entry: {
    popup: './src/popup/popup.js',
    background: './src/background/background.js',
    content: './src/content/content.js'
  },
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: '[name].js',
    clean: true,
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env']
          }
        }
      },
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader']
      }
    ]
  },
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: path.resolve(__dirname, 'src/assets'),
          to: path.resolve(__dirname, 'dist/icons')
        },
        {
          from: path.resolve(__dirname, 'public/manifest.json'),
          to: path.resolve(__dirname, 'dist/manifest.json')
        }
      ]
    }),
    new HtmlWebpackPlugin({
      template: './src/popup/popup.html',
      filename: 'popup.html',
      chunks: ['popup']
    })
  ]
};