Babel: Unexpected token (e.g., import)

Babel: Unexpected Token (e.g., import) Error – Detailed Explanation and Solution

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What is the “Unexpected Token” Error in Babel?

When you see an error like:

SyntaxError: Unexpected token 'import'

or

Module parse failed: Unexpected token (1:0)

it usually means that Babel is not correctly transpiling modern JavaScript (ES6+) code, such as import/export statements, into a format that your runtime environment (like Node.js or a browser) can understand.

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Why Does This Error Happen?

The error occurs because of one or more of the following reasons:

1. Babel is not installed or configured properly
   • If Babel isn’t set up correctly in your project, it won’t transform ES6+ syntax.
2. Incorrect Babel Presets or Plugins
   • Babel requires certain presets like @babel/preset-env or @babel/preset-react to handle modern JavaScript and JSX.
3. Babel is not being applied to node_modules
   • By default, Babel doesn’t transpile node_modules, so dependencies using modern JavaScript may cause this error.
4. Using ES Modules (import/export) in a Node.js environment that doesn’t support them
   • Node.js (prior to v12) doesn’t support ES modules unless you explicitly enable them.
5. Incorrect Webpack Configuration
   • If Webpack is not set up to use Babel properly, the import/export statements won’t be transpiled.

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Step-by-Step Fixes

Step 1: Check Babel Installation

Make sure Babel is installed in your project by running:

npm list --depth=0 | grep babel

or for Yarn:

yarn list --depth=0 | grep babel

If Babel is missing, install it using:

npm install --save-dev @babel/core @babel/cli @babel/preset-env @babel/preset-react @babel/plugin-transform-runtime

For TypeScript projects, also install:

npm install --save-dev @babel/preset-typescript

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Step 2: Configure Babel Properly

Ensure you have a .babelrc or babel.config.json file in your project root with the following content:

For General JavaScript (React and Modern ES6+ JavaScript)

{
  "presets": ["@babel/preset-env", "@babel/preset-react"],
  "plugins": ["@babel/plugin-transform-runtime"]
}

For TypeScript

{
  "presets": ["@babel/preset-env", "@babel/preset-react", "@babel/preset-typescript"]
}

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Step 3: Ensure Babel is Used in Webpack

If you’re using Webpack, make sure Babel is correctly set up in webpack.config.js:

module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: "babel-loader"
        }
      }
    ]
  }
};

If using JSX or TypeScript:

module.exports = {
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
          loader: "babel-loader"
        }
      }
    ]
  }
};

Ensure babel-loader is installed:

npm install --save-dev babel-loader

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Step 4: Allow Babel to Process node_modules (if needed)

By default, Babel doesn’t transpile code inside node_modules, which may cause issues if you’re using a package with modern JavaScript syntax.

To fix this, modify webpack.config.js:

module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        include: /node_modules\/some-es6-library/,
        use: {
          loader: "babel-loader"
        }
      }
    ]
  }
};

Replace some-es6-library with the actual package name.

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Step 5: Use CommonJS Instead of ES Modules (For Node.js)

If you’re running a Node.js application and see this error, try using CommonJS instead of ES modules:

const myModule = require("./myModule"); // CommonJS

If you still want to use ES Modules, make sure:

• Your package.json has: { "type": "module" }
• You run the script with: node --experimental-modules index.mjs

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Step 6: Restart Your Development Server

After making changes, restart your server:

npm run dev

or

yarn start

If using Webpack, rebuild your project:

npm run build

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Final Thoughts

• Double-check your Babel installation.
• Ensure Babel is configured correctly with the right presets.
• Make sure Webpack (if used) is processing files through Babel.
• Enable CommonJS if running Node.js.
• Restart the development server after making changes.

By following these steps, the “Unexpected token ‘import'” error should be resolved, and your JavaScript project will work as expected.