Module parse failed: Unexpected token

Explanation of the problem

import _regeneratorRuntime from"/data_b/work/gitlab-runner/builds/622b053b/0/lala/test/node_modules/babel-preset-react-app/node_modules/@babel/runtime/regenerator";
import _objectSpread from"/data_b/work/gitlab-runner/builds/622b053b/...

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Problem solution for Module parse failed: Unexpected token

The error message “Module parse failed: Unexpected token” typically occurs when there is an issue with Babel’s module parsing process. One possible solution is to change the compact option of Babel to false. This is a short-term fix that may resolve the problem, but it is not a permanent solution. The compact option is a flag that determines whether or not Babel should output compact code. Changing this option can be done in the webpack configuration file, specifically at the line number 438. This solution may work for some cases, but it is important to note that it does not address the root cause of the issue.

{
  test: /\.(js|mjs|jsx|ts|tsx)$/,
  include: paths.appSrc,
  loader: require.resolve('babel-loader'),
  options: {
    customize: require.resolve(
      'babel-preset-react-app/webpack-overrides'
    ),

    // The 'false' value here means to use the default Babel settings
    // for compact mode, which is to omit whitespace and comments.
    compact: false,
    plugins: [
      [
        require.resolve('babel-plugin-named-asset-import'),
        {
          loaderMap: {
            svg: {
              ReactComponent: '@svgr/webpack?-svgo,+titleProp,+ref![path]',
            },
          },
        },
      ],
    ],
    cacheDirectory: true,
    cacheCompression: isEnvProduction,
    // See #6846 for context on why cacheCompression is disabled
    compact: isEnvProduction,
  },
  // ...
}

Another possible cause of the “Unexpected token” error is the incompatibility of some dependencies with Babel/core version 7.15.0. When upgrading to this version, some plugins and presets may become incompatible, leading to module parsing failures. Identifying the specific dependency causing the issue can be challenging, as the error message does not provide much information. One possible solution that has worked for some users is to upgrade all Babel plugins and presets to their latest versions. This can be done by running the command “npm update @babel/core @babel/preset-env @babel/preset-react” in the terminal. However, this solution may not be effective for all cases, and further investigation may be required.

npm update @babel/core @babel/preset-env @babel/preset-react

​

Other popular problems with Creating a react app

Solution:

To reduce the bundle size, developers can use tools like code splitting and tree shaking. Code splitting involves breaking up the code into smaller chunks that can be loaded on-demand instead of all at once. Tree shaking is a technique that removes unused code from the final bundle. Additionally, developers can use libraries like Loadable Components to split the code more efficiently.

Problem: Lack of Server-Side Rendering

The third issue with create-react-app is the lack of built-in support for server-side rendering. Server-side rendering can improve the application’s performance, especially for users on slow connections or with slower devices. It can also help with SEO and provide a better user experience.

Solution:

To add server-side rendering, developers can use tools like Next.js or Gatsby. Next.js is a framework that allows developers to build server-rendered React applications easily. Gatsby is a static site generator that allows developers to build static websites with React components. Both tools provide an easy way to add server-side rendering to a React application while maintaining compatibility with create-react-app.

Most popular use cases for creating a react app

1. Rapid Development: Create-react-app is designed to help developers quickly and efficiently create React applications without the need for manual configuration. By running a single command, developers can create a new React application with a pre-configured development environment that includes a server, hot-reloading, and many other features that make it easy to start building React applications. With Create-react-app, developers can focus on writing their code instead of spending time setting up the development environment.
2. Customization: While Create-react-app provides a pre-configured development environment, it is also highly customizable. Developers can easily modify the configuration to suit their specific needs by using configuration files, such as .env, .babelrc, and webpack.config.js. This allows developers to add additional features, such as support for CSS preprocessors or custom webpack plugins, to their React applications.

Here is an example of how to add support for SASS in Create-react-app:

npm install node-sass