webpack.config.js

const path = require('path');
const AwsSamPlugin = require('aws-sam-webpack-plugin');

const awsSamPlugin = new AwsSamPlugin({ vscodeDebug: false });

module.exports = {
  // Loads the entry object from the AWS::Serverless::Function resources in your
  // SAM config. Setting this to a function will
  entry: () => awsSamPlugin.entry(),

  // Write the output to the .aws-sam/build folder
  output: {
    filename: (chunkData) => awsSamPlugin.filename(chunkData),
    libraryTarget: 'commonjs2',
    path: path.resolve('.')
  },

  // Create source maps
  devtool: 'source-map',

  // Resolve .ts and .js extensions
  resolve: {
      extensions: ['.ts', '.js']
  },

  // Target node
  target: 'node',

  // AWS recommends always including the aws-sdk in your Lambda package but excluding can significantly reduce
  // the size of your deployment package. If you want to always include it then comment out this line. It has
  // been included conditionally because the node10.x docker image used by SAM local doesn't include it.
  externals: process.env.NODE_ENV === 'development' ? [] : ['aws-sdk'],

  // Set the webpack mode
  mode: process.env.NODE_ENV || 'production',

  // Add the TypeScript loader
  module: {
      rules: [{ test: /\.tsx?$/, loader: 'ts-loader' }]
  },

  // Add the AWS SAM Webpack plugin
  plugins: [awsSamPlugin]
};