webpack.config.server.js

const path = require("path");
const nodeExternals = require("webpack-node-externals");

const entry = { server: "./src/server/index.ts" };

module.exports = {
  mode: process.env.NODE_ENV ? process.env.NODE_ENV : "development",
  target: "node",
  devtool: "inline-source-map",
  entry: entry,
  output: {
    path: path.resolve(__dirname, "build"),
    filename: "[name].js"
  },
  resolve: {
    extensions: [".ts", ".tsx", ".js", "jsx"]
  },
  // don't compile node_modules
  externals: [nodeExternals()],
  module: {
    rules: [
      {
        test: /\.(js|mjs|jsx|ts|tsx)$/,
        use: [
          {
            loader: "ts-loader",
            options: {
              // use the tsconfig in the server directory
              configFile: "src/server/tsconfig.json"
            }
          }
        ]
      },
      {
        test: /\.s[ac]ss$/i,
        use: [
          // Creates `style` nodes from JS strings
          "style-loader",
          // Translates CSS into CommonJS
          "css-loader",
          // Compiles Sass to CSS
          "sass-loader"
        ]
      }
    ]
  }
};