webpack.config.js

const path = require('path');
const Dotenv = require('dotenv-webpack');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const GasPlugin = require('gas-webpack-plugin');
const es3ifyPlugin = require('es3ify-webpack-plugin');
const { version } = require('./package.json');

const destination = 'dist';
// Note: As recommended in https://github.com/fossamagna/gas-webpack-plugin/issues/135#issuecomment-396093757
const mode = 'none';

module.exports = {
  devtool: false,
  entry: './src/index.ts',
  mode,
  output: {
    filename: `code-${version}.js`,
    path: path.resolve(__dirname, destination),
    libraryTarget: 'this'
  },
  resolve: {
    extensions: ['.ts', '.js'],
  },
  module: {
    rules: [
      {
        test: /\.ts?$/,
        exclude: /node_modules/,
        use: [
          {
            loader: 'babel-loader',
          },
          {
            loader: 'ts-loader'
          }
        ],
      },
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader'
        }
      }
    ],
  },
  plugins: [
    new Dotenv({
      safe: true,
    }),
    new CleanWebpackPlugin([destination]),
    new CopyWebpackPlugin(
      {
        patterns: [
          {
            from: './appsscript.json',
            to: path.resolve(__dirname, destination)
          }
        ]
      }
      ),
    new GasPlugin(),
    new es3ifyPlugin(),
  ],
};