Best Way To Polyfill Es6 Features In React App That Uses Create React App

When it comes to developing React applications using Create React App, ensuring compatibility with ES6 features across different browsers can sometimes be a tricky task. However, fear not, as polyfilling ES6 features in your React app can make your development process smoother and more efficient. In this article, we will explore the best way to polyfill ES6 features in your React app created with Create React App.

Firstly, for those unfamiliar with the term, polyfilling involves adding code to emulate browser features that are not natively supported. In the context of ES6 features, polyfills are essential for ensuring your modern JavaScript code works across all browsers, especially older ones that may not fully support the latest ECMAScript standards.

To polyfill ES6 features in your Create React App, one popular tool you can use is `react-app-rewired`. This tool allows you to customize the webpack configuration of your Create React App without ejecting it, which can save you a lot of time and effort.

Here is a step-by-step guide on how to polyfill ES6 features in your React app using `react-app-rewired`:

1. Install `react-app-rewired` and the necessary polyfill packages by running the following command in your project directory:

npm install react-app-rewired @babel/preset-env core-js regenerator-runtime

2. Create a `config-overrides.js` file in the root of your project directory. This file will contain the custom webpack configuration for polyfilling ES6 features.

3. Inside the `config-overrides.js` file, add the following code to configure the babel loader to use `@babel/preset-env` and include the necessary polyfills:

module.exports = function override(config, env) {
  config.module.rules[2].oneOf.forEach(rule => {
    if (rule.loader && rule.loader.includes('babel-loader')) {
      rule.options.presets = [
        require.resolve('@babel/preset-env'),
        ...rule.options.presets
      ];
      rule.options.plugins = rule.options.plugins || [];
      rule.options.plugins.push([
        require.resolve('babel-plugin-transform-runtime'), { corejs: 3 }
      ]);
    }
  });

  return config;
};

4. Update the `package.json` scripts to use `react-app-rewired` for starting the development server and building the project:

"scripts": {
  "start": "react-app-rewired start",
  "build": "react-app-rewired build"
}

5. Finally, run your React app using the updated scripts:

npm start

By following these steps, you can effectively polyfill ES6 features in your React app created with Create React App. This approach ensures that your modern JavaScript code remains compatible with a wide range of browsers, providing a seamless user experience for all your app users.

In conclusion, polyfilling ES6 features in your React app is an essential step to ensure cross-browser compatibility and a consistent user experience. With tools like `react-app-rewired`, you can easily customize the webpack configuration of your Create React App to include the necessary polyfills without ejecting the project. Happy coding!