webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");

module.exports = {
  entry: './src/index.tsx',
  output: {
    path: path.resolve(__dirname, 'build'),
    publicPath: '/',
    filename: 'bundle.js',
  },
  mode: 'development', 
  devServer: {
    // Required for Docker to work with dev server
    // host: '0.0.0.0',
    host:'localhost',
    port: 8080,
    // match the output path
    contentBase: path.resolve(__dirname, 'build'),
    //enable HMR on the devServer
    hot: true,
    //match the output 'publicPath'
    publicPath: '/',
    // fallback to root for other urls
    historyApiFallback: true,
    inline: true,
    headers: { 'Access-Control-Allow-Origin': '*' },

    // proxy is required in order to make api calls to express server while using hot-reload webpack server
    // routes api fetch requests from localhost:8080/api/* (webpack dev server) to localhost:3000/api/* (where our Express server is running)
    proxy: {
      '/testing-ab': {
        target: 'http://localhost:3000/',
        secure: false,
      },
      '/data': {
        target: 'http://localhost:3000/',
        secure: false,
      },
    },
  }, 
  module: {
    rules: [ 
      {
        test: /\.tsx?$/,
        exclude: /node_modules/,
        use:
        {
          loader: "ts-loader",
        }
      },
      {
        enforce: "pre",
        test: /\.js$/,
        use:
        {
          loader: "source-map-loader"
        }
      },
      {
        test: /\.scss$/,
        use: [
            MiniCssExtractPlugin.loader,
            { loader: 'css-loader', options: { sourceMap: true, importLoaders: 1 } },
            { loader: 'sass-loader', options: { sourceMap: true } },
        ],
      },
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader']
      }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: "./index.html"
    }),
    new MiniCssExtractPlugin({
      // Options similar to the same options in webpackOptions.output
      // both options are optional
      filename: '[name].css',
      chunkFilename: '[id].css',
    })
  ],
  devtool: "source-map",
  resolve: {
    extensions: [".js", ".ts", ".tsx"]
  }
}