babel-plugin-transform-es2015-modules-commonjs

This plugin transforms ES2015 modules to CommonJS.

Example

In

export default 42;

Out

Object.defineProperty(exports, "__esModule", {
  value: true
});

exports.default = 42;

Installation

npm install --save-dev babel-plugin-transform-es2015-modules-commonjs

Usage

Via .babelrc (Recommended)

.babelrc

// without options
{
  "plugins": ["transform-es2015-modules-commonjs"]
}

// with options
{
  "plugins": [
    ["transform-es2015-modules-commonjs", {
      "allowTopLevelThis": true
    }]
  ]
}

Via CLI

babel --plugins transform-es2015-modules-commonjs script.js

Via Node API

require("babel-core").transform("code", {
  plugins: ["transform-es2015-modules-commonjs"]
});

Options loose

As per the spec, import and export are only allowed to be used at the top level. When in loose mode these are allowed to be used anywhere.

And by default, when using exports with babel a non-enumerable __esModule property is exported.

var foo = exports.foo = 5;

Object.defineProperty(exports, "__esModule", {
  value: true
});

In environments that don't support this you can enable loose mode on es6.modules and instead of using Object.defineProperty an assignment will be used instead.

var foo = exports.foo = 5;
exports.__esModule = true;