Require Hook

One of the ways you can use Babel is through the require hook. The require hook will bind itself to node's require and automatically compile files on the fly. This is equivalent to CoffeeScript's coffee-script/register.

Not suitable for libraries

The require hook automatically hooks itself into all node requires. This will pollute the global scope and introduce conflicts. If you're writing an application, it's completely fine to use. If, however, you're writing a library then you should compile your library and depend on the babel-runtime.

utility.inlineEnvironmentVariables use

Please note the when used in conjunction.

Install

$ npm install babel

Usage

require("babel/register");

All subsequent files required by node with the extensions .es6, .es, .jsx and .js will be transformed by Babel. The polyfill is also automatically required.

NOTE: By default all requires to node_modules will be ignored. You can override this by passing an ignore regex via:

require("babel/register")({
  // This will override `node_modules` ignoring - you can alternatively pass
  // an array of strings to be explicitly matched or a regex / glob
  ignore: false
});

Specifying options

require("babel/register")({
  // Optional ignore regex - if any filenames **do** match this regex then they
  // aren't compiled.
  ignore: /regex/,

  // Ignore can also be specified as a function.
  ignore: function(filename) {
    if (filename === '/path/to/es6-file.js') {
      return false;
    } else {
      return true;
    }
  },

  // Optional only regex - if any filenames **don't** match this regex then they
  // aren't compiled
  only: /my_es6_folder/,

  // See options above for usage
  whitelist: [],
  blacklist: [],

  // Setting this will remove the currently hooked extensions of .es6, `.es`, `.jsx`
  // and .js so you'll have to add them back if you want them to be used again.
  extensions: [".es6", ".es", ".jsx", ".js"]
});

You can pass in all other options as well.

Environment variables

By default babel-node and babel/register will save to a json cache in your temporary directory.

This will heavily improve with the startup and compilation of your files. There are however scenarios where you want to change this behaviour and there are environment variables exposed to allow you to do this.

BABEL_CACHE_PATH

Specify a different cache location.

$ BABEL_CACHE_PATH=/foo/my-cache.json babel-node script.js

BABEL_DISABLE_CACHE

Disable the cache.

$ BABEL_DISABLE_CACHE=1 babel-node script.js