babel-plugin-transform-modules-requirejs-babel

A Babel plugin transforming ESM modules to AMD modules, so that they will be processable by RequireJS with the help of the requirejs-babel7 plugin.

The built-in plugin for the AMD module transformation - @babel/plugin-transform-modules-amd - covers only a simple scenario transform an ESM code base, which used AMD only as module format, without additional other RequireJS features. This plugin supports scenarios using all capabilities of RequireJS, above all:

• Mixing ESM and AMD modules at any dependency level.
• If an ESM module contains a single default export, it will be exported from the AMD module without wrapping to { default: ... } to keep the compatibility. An AMD module can be rewritten to ESM and vice-versa anytime.
• AMD module bundles with multiple define statements are recognised.

Table of Contents

• History
• Installation
• Babel Configuration Examples
• Contributing
• License

History

This plugin replaces a couple of plugins usually used together with requirejs-babel7: @babel/plugin-transform-modules-amd, babel-plugin-amd-checker, babel-plugin-amd-default-export and babel-plugin-module-resolver-standalone. An example of a Babel configuration using those plugins:

{
  plugins: [
    'amd-checker',
    'transform-modules-amd',
    [
      'module-resolver',
      {
        resolvePath: function (sourcePath, currentFile, opts) {
          // Ignore paths with other plugins applied and the three built-in
          // pseudo-modules of RequireJS.
          if (sourcePath.indexOf('!') < 0 && sourcePath !== 'require' &&
            sourcePath !== 'module' && sourcePath !== 'exports') {
            return 'es6!' + sourcePath;
          }
        }
      }
    ],
    ['amd-default-export', { addDefaultProperty: false }]
  ]
}

Their combination did not support mixing ESM and AMD modules at any dependency level. Skipping of AMD modules had to be handled by catching an error of a special class, which needed to wrap Babel programmatically. The new plugin covers amm problems of the built-in AMD transformation, which the previous ones did, without any drawbacks.

Installation

This module can be installed in your project using NPM, PNPM or Yarn. Make sure, that you use Node.js version 6 or newer.

npm i -D babel-plugin-transform-modules-requirejs-babel
pnpm i -D babel-plugin-transform-modules-requirejs-babel
yarn add babel-plugin-transform-modules-requirejs-babel

Babel Configuration Examples

Prevent the transpiler to wrap source files that are already wrapped by define or require as AMD modules:

{
  plugins: ['transform-modules-requirejs-babel']
}

Customising the default module path transformation:

{
  plugins: [
    [
      'transform-modules-requirejs-babel',
      {
        resolvePath: function (sourcePath, currentFile, opts) {
          // Ignore paths with other plugins applied and the three built-in
          // pseudo-modules of RequireJS.
          if (sourcePath.indexOf('!') < 0 && sourcePath !== 'require' &&
            sourcePath !== 'module' && sourcePath !== 'exports') {
            return 'es6!' + sourcePath;
          }
        }
      }
    ]
  ]
}

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Lint and test your code.

License

Copyright (c) 2022 Ferdinand Prantl

Licensed under the MIT license.