webpack.config.js

const path = require("path");
const HtmlWebpackPlugin = require("html-webpack-plugin");

module.exports = {
  entry: "./src/app.js",
  mode: process.env.NODE_ENV,
  output: {
    filename: "bundle.js",
    path: path.resolve(__dirname, "dist"),
    publicPath: "/",
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: "./src/index.html",
    }),
  ],
  module: {
    rules: [
      {
        test: /\.jsx?/,
        exclude: /node_modules/,
        loader: "babel-loader",
        options: {
          presets: ["@babel/preset-react", "@babel/preset-env"],
        },
      },
      {
        test: /css$/i,
        use: ["style-loader", "css-loader"],
      },
      {
        test: /\.(png|jpe?g|gif)$/i,
        use: [
          {
            loader: "file-loader",
          },
        ],
      },
    ],
  },
  resolve: {
    extensions: [".js", ".jsx"],
  },
  devServer: {
    contentBase: path.resolve(__dirname, "dist"),
    publicPath: "/",
    proxy: {
      "/callback": "http://localhost:3000/",
      "/": "http://localhost:3000/",
    },
    historyApiFallback: true,
  },
};