babel/packages/babel-plugin-transform-modules-commonjs

@babel/plugin-transform-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-modules-commonjs

Usage

Via .babelrc (Recommended)

.babelrc

// without options
{
  "plugins": ["@babel/plugin-transform-modules-commonjs"]
}

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

Via CLI

babel --plugins @babel/plugin-transform-modules-commonjs script.js

Via Node API

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

Options

loose

boolean, defaults to false.

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 @babel/plugin-transform-modules-commonjs and instead of using Object.defineProperty an assignment will be used instead.

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

strict

boolean, defaults to false

By default, when using exports with babel a non-enumerable __esModule property is exported. In some cases this property is used to determine if the import is the default export or if it contains the default export.

var foo = exports.foo = 5;

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

In order to prevent the __esModule property from being exported, you can set the strict option to true.

noInterop

boolean, defaults to false

By default, when using exports with babel a non-enumerable __esModule property is exported. This property is then used to determine if the import is the default export or if it contains the default export.

"use strict";

var _foo = _interopRequireDefault(require("foo"));

function _interopRequireDefault(obj) {
  return obj && obj.__esModule ? obj : { default: obj };
}

In cases where the auto-unwrapping of default is not needed, you can set the noInterop option to true to avoid the usage of the interopRequireDefault helper (shown in inline form above).