Babel 6 Regeneratorruntime Is Not Defined

Babel 6 regeneratorRuntime is not defined

If you are encountering the error “regeneratorRuntime is not defined” when using Babel 6, don’t worry, you are not alone. This error typically occurs when you are trying to use generator functions or async/await syntax without including the necessary runtime support. In this blog post, we will explore two solutions to resolve this issue.

Solution 1: Using @babel/preset-env

The first solution is to use the @babel/preset-env package which includes the necessary polyfills and transformations based on the target environment you specify. To fix the “regeneratorRuntime is not defined” error, follow these steps:

Install the required packages:

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

Update your Babel configuration file (usually .babelrc) to include the following:

{
  "presets": [
    ["@babel/preset-env", {
      "useBuiltIns": "usage",
      "corejs": 3
    }]
  ],
  "plugins": [
    "@babel/plugin-transform-runtime"
  ]
}

Make sure to adjust the configuration according to your needs. The useBuiltIns option with a value of "usage" will automatically import the necessary polyfills based on your code usage. The corejs option specifies the version of core-js to use.

Solution 2: Manually importing regenerator-runtime

If you prefer not to use @babel/preset-env, you can manually import the regenerator-runtime package in your code. Follow these steps:

Install the required package:

npm install --save regenerator-runtime

Import regenerator-runtime at the entry point of your application:

// ES6 import
import 'regenerator-runtime/runtime';

// CommonJS require
require('regenerator-runtime/runtime');

Conclusion

By following either of the above solutions, you should be able to resolve the “regeneratorRuntime is not defined” error when using Babel 6. Choose the solution that best fits your needs and enjoy using generator functions and async/await syntax in your JavaScript code.

Babel 6 Regeneratorruntime Is Not Defined