ReactJs Production Code- Uncaught ReferenceError: process is not defined

Question

So I have a bit of an issue with by ReactJs production code where it doesn't seem to recognize my environment variables. This is the error I get:

Uncaught ReferenceError: process is not defined
    <anonymous> webpack://testProject/./src/agent.js?:9
    js http://localhost:8080/src_Admin_MainPage_SessionTimeout_index_js-src_agent_js-node_modules_moment_locale_sync_recursive_.js:29
    __webpack_require__ http://localhost:8080/main.js:2511
    fn http://localhost:8080/main.js:2789
    <anonymous> webpack://coralpanda/./src/Admin/MainPage/Login/index.js?:5
    js http://localhost:8080/src_Admin_MainPage_index_js.js:28
    __webpack_require__ http://localhost:8080/main.js:2511
    fn http://localhost:8080/main.js:2789
    <anonymous> webpack://coralpanda/./src/Admin/MainPage/index.js?:4
    js http://localhost:8080/src_Admin_MainPage_index_js.js:128
    __webpack_require__ http://localhost:8080/main.js:2511
    fn http://localhost:8080/main.js:2789

I followed Webpack's documentation for passing in environment variables and added them to my package.json file's build settings, but it didn't work. Here's how it looks:

"scripts": {
    "start": "react-scripts start",
    "build": "webpack --mode=production --env REACT_APP_SERVER_URL=https://localhost:3481/project --env NODE_PATH=./src  --node-env=production",
    "test": "react-scripts test",
    "eject": "react-scripts eject",
    "build:dev": "webpack --mode=development",
    "build:prod": "webpack --mode=production --node-env=production",
    "watch": "webpack --watch",
    "serve": "webpack serve"
  },

And here is my webpack.config.js just in case:

// Generated using webpack-cli https://github.com/webpack/webpack-cli

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

const isProduction = process.env.NODE_ENV == "production";

const stylesHandler = isProduction
  ? MiniCssExtractPlugin.loader
  : "style-loader";

const config = {
  entry: "./src/index.js",
  output: {
    path: path.resolve(__dirname, "build"),
  },
  devServer: {
    open: true,
    host: "localhost",
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: "index.html",
    }),

    // Add your plugins here
    // Learn more about plugins from https://webpack.js.org/configuration/plugins/
  ],
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/i,
        loader: "babel-loader",
      },
      {
        test: /\.s[ac]ss$/i,
        use: [stylesHandler, "css-loader", "postcss-loader", "sass-loader"],
      },
      {
        test: /\.css$/i,
        use: [stylesHandler, "css-loader", "postcss-loader"],
      },
      {
        test: /\.(eot|svg|ttf|woff|woff2|png|jpg|gif)$/i,
        type: "asset",
      },

      // Add your rules for custom modules here
      // Learn more about loaders from https://webpack.js.org/loaders/
    ],
  },
  resolve: {
    alias: {
      assets: path.resolve(__dirname, 'src/assets/'),
      agent: path.resolve(__dirname, 'src/agent.js'),
      "agent.js": path.resolve(__dirname, 'src/agent.js'),
      Admin: path.resolve(__dirname, 'src/Admin'),
    }
  },
};

module.exports = () => {
  if (isProduction) {
    config.mode = "production";

    config.plugins.push(new MiniCssExtractPlugin());

    config.plugins.push(new WorkboxWebpackPlugin.GenerateSW());
  } else {
    config.mode = "development";
  }
  return config;
};

Answer 1

Fixed the issue. The answer was EnvironmentPlugin. So I had to add that for webpack to recognize my environment variables. I added the following lines to my webpack.config.js:

const { EnvironmentPlugin } = require('webpack')

const config={
    plugins:[
        new EnvironmentPlugin({
      REACT_APP_SERVER_URL: "https://localhost:3481/project",
      NODE_PATH: "src/"
    })
    ]
}