webpack.config.js

const path = require("path");
const slsw = require("serverless-webpack");
const ForkTsCheckerWebpackPlugin = require("fork-ts-checker-webpack-plugin");
const nodeExternals = require("webpack-node-externals");
const TsconfigPathsPlugin = require("tsconfig-paths-webpack-plugin");
module.exports = {
  // `mode` will be set to `production` and comes with included optimizations
  // when building to be run on AWS or similar.
  // https://webpack.js.org/configuration/mode/
  mode: slsw.lib.webpack.isLocal ? "development" : "production",
  // to determine what source maps to use per dev or prod
  // https://webpack.js.org/configuration/devtool/
  devtool: slsw.lib.webpack.isLocal ? "source-map" : "cheap-source-map",

  // the provided argument will be an object referencing functions as defined
  // in your `serverless.yml` .
  // https://webpack.js.org/concepts/entry-points/
  entry: slsw.lib.entries,
  target: "node",
  resolve: {
    // What file extensions we want Webpack to care about, and in what order
    // https://webpack.js.org/configuration/resolve/#resolveextensions
    extensions: [".cjs", ".mjs", ".js", ".ts"],
    // `yarn add -D tsconfig-paths-webpack-plugin` if you need path aliases
    plugins: [new TsconfigPathsPlugin()],
  },
  // Where the bundled files will be output. Not strictly necessary with
  // Serverless Webpack.
  // https://webpack.js.org/configuration/output/
  output: {
    libraryTarget: "commonjs2",
    path: path.join(__dirname, ".webpack"),
    filename: "[name].js",
  },
  optimization: {
    nodeEnv: false,
  },
  // Anything that will be available to the bundled code in the runtime
  // environment and does not need to be included in any of the bundles.
  //
  // In AWS Lambda, the `aws-sdk` is available and we almost certainly want to
  // exclude it from our bundle(s). Similarly, because it's a Node lambda,
  // Node's native modules will also be available.
  externals: ["aws-sdk", nodeExternals()],
  module: {
    // Instruct Webpack to use the `ts-loader` for any TypeScript files, else it
    // won't know what to do with them.
    rules: [
      {
        test: /\.ts$/,
        exclude: /node_modules/,
        loader: "ts-loader",
        exclude: [
          [
            path.resolve(__dirname, ".webpack"),
            path.resolve(__dirname, ".serverless"),
          ],
        ],
        // And here we have options for ts-loader
        // https://www.npmjs.com/package/ts-loader#options
        options: {
          // Disable type checking, this will lead to improved build times
          transpileOnly: true,
          // Enable file caching, can be quite useful when running offline
          experimentalFileCaching: true,
        },
      },
    ],
  },
  // We still want type checking, just without the burden on build performance,
  // so we use a plugin to take care of it on another thread.
  plugins: [new ForkTsCheckerWebpackPlugin()],
};