webpack.config.js

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

const mode = process.env.NODE_ENV;

module.exports = {
  entry: path.resolve(__dirname, './client/index.js'),
  mode: process.env.NODE_ENV,
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, './build'),
  },
  //dev
  devServer: {
    publicPath: '/build/', //matches the path for the production output
    proxy: {
      '/**': {
        target: 'http://localhost:3000' //will this affect web socket ports?
      }
    }
  },
  module: {
    rules: [
      // list of rules include objects with test and use properties
      //babel processes jsx files
      {
        test: /.(js|jsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            //preset-env is overall environment, passing react narrows down scope of environment for transpilations
            presets: ['@babel/preset-env', '@babel/preset-react'],
            plugins: ['@babel/plugin-transform-runtime', '@babel/transform-async-to-generator'],
          }
        }
      },
      //image loaders
      {
        test: /\.(png|jpe?g|gif)$/i,
        exclude: /gifs/,
        // loader: "file-loader?name=/static/RPS_View_logo.png",
        use: [
          {
          loader: 'url-loader',
          options: {
            // outputPath: 'static',
            limit: false,
          }
         }]
      },
      //style loaders
      {
        test: /\.s[ac]ss$/i,
        use: [
          // Creates `style` nodes from JS strings (third)
          'style-loader',
          // Translates CSS into CommonJS (second)
          'css-loader',
          // Compiles Sass to CSS (first)
          'sass-loader',
        ],
      },
      //extracts css for faster loading
      {
        test: /\.css$/i,
        use: [MiniCssExtractPlugin.loader, 'css-loader'],
      },
    ]
  },
  resolve: {
    extensions: ['.js', '.jsx'],
  },
  plugins: [
    new MiniCssExtractPlugin(),
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify(mode),
    })
    
  ]
};