Webpack configs for Node.js backends to run both locally and on AWS Lambda

babel.config.js

module.exports = {
  presets: [
    '@babel/preset-react',
    [
      '@babel/preset-env',
      {
        targets: {
          node: 'current',
        },
      },
    ],
    '@babel/preset-typescript',
  ],
  plugins: [
    'relay',
    'babel-plugin-idx',
    'babel-plugin-styled-components',
    '@babel/plugin-proposal-object-rest-spread',
    '@babel/plugin-proposal-class-properties',
    '@babel/plugin-proposal-export-default-from',
    '@babel/plugin-proposal-export-namespace-from',
    '@babel/plugin-transform-async-to-generator',
    '@babel/plugin-proposal-async-generator-functions',
    '@babel/plugin-proposal-nullish-coalescing-operator',
    '@babel/plugin-proposal-optional-chaining',
  ],
  env: {
    test: {
      presets: [
        '@babel/preset-react',
        ['@babel/preset-env', { targets: { node: 'current' } }],
        '@babel/preset-typescript',
      ],
      plugins: [
        'relay',
        'babel-plugin-idx',
        'babel-plugin-styled-components',
        '@babel/plugin-proposal-object-rest-spread',
        '@babel/plugin-proposal-class-properties',
        '@babel/plugin-proposal-export-default-from',
        '@babel/plugin-proposal-export-namespace-from',
        '@babel/plugin-transform-async-to-generator',
        '@babel/plugin-proposal-async-generator-functions',
        '@babel/plugin-proposal-nullish-coalescing-operator',
        '@babel/plugin-proposal-optional-chaining',
      ],
    },
  },
};

webpack.common.js

// common config shared between multiple servers
const path = require('path');

const webpack = require('webpack');
const TerserPlugin = require('terser-webpack-plugin');

module.exports = {
  target: 'node',
  optimization: {
    minimizer: [new TerserPlugin()],
  },
  externals: [{ 'aws-sdk': 'aws-sdk' }],
  resolve: {
    extensions: ['.ts', '.tsx', '.js', 'jsx', '.json', '.mjs'],
  },
  output: {
    path: path.resolve(__dirname, 'build'),
    filename: '[name].js',
    library: 'index',
    libraryTarget: 'commonjs2',
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env.BROWSER': false,
      __DEV__: process.env.NODE_ENV !== 'production',
    }),
  ],
  module: {
    rules: [
      {
        test: /\.mjs$/,
        include: /node_modules/,
        type: 'javascript/auto',
      },
      {
        test: /\.([jt]sx?)$/,
        loader: 'babel-loader',
        options: {
          configFile: './babel.config.js',
        },
        exclude: /node_modules/,
      },
    ],
  },
};

webpack.graphql.js

// config to run local server for development
// the entry file is the index.ts since it creates a http server
const path = require('path');

const webpack = require('webpack');
const merge = require('webpack-merge');
const ReloadServerPlugin = require('reload-server-webpack-plugin');

const common = require('./webpack.common.js');

module.exports = merge(common, {
  mode: 'development',
  entry: {
    graphql: './src/graphql/index.ts',
  },
  watch: true,
  stats: {
    warnings: true,
  },
  plugins: [
    new webpack.HotModuleReplacementPlugin(),
    new ReloadServerPlugin({
      script: path.resolve('build', 'graphql.js'),
    }),
  ],
});

webpack.production.js

// config to build a graphql.js to run on AWS Lambda
// the entry file is index.lambda.ts which is an event handler
// compatible for AWS Lambda
const merge = require('webpack-merge');

const common = require('./webpack.common.js');

module.exports = merge(common, {
  mode: 'production',
  entry: {
    graphql: './src/graphql/index.lambda.ts',
  },
});