# @chiffon/babel-webpack-plugin

> webpack plugin for compiling multiple JavaScript bundles with babel

Latest version **0.0.2** (published 2019-08-12) · MIT license · 0 weekly downloads

## Install

```sh
npm install @chiffon/babel-webpack-plugin
pnpm add @chiffon/babel-webpack-plugin
yarn add @chiffon/babel-webpack-plugin
bun add @chiffon/babel-webpack-plugin
```

## Health

**Score 25/100 (F)** — status: abandoned.

Positive: has types; no vulnerabilities; high quality score.

Warnings: low downloads; no esm support; pre 1.0.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 0.0.2 |
| Published | 2019-08-12 |
| First published | 2019-08-11 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | CommonJS |
| Node | >=10 |
| Dependencies | 2 |
| Unpacked size | 39.5 KB |
| Known vulnerabilities | 0 (+3 in 1 direct dependencies) |
| Install scripts | no |
| Maintainers | li-kai |

## Links

- npm: https://www.npmjs.com/package/@chiffon/babel-webpack-plugin
- npm.io page: https://npm.io/package/@chiffon/babel-webpack-plugin

## Dependencies (2)

- [loader-utils](https://npm.io/package/loader-utils.md) 1.2.3
- [webpack-sources](https://npm.io/package/webpack-sources.md) 1.4.3

## Recent versions

- 0.0.2 (latest) — 2019-08-12
- 0.0.1 — 2019-08-11

## README

# @chiffon/babel-webpack-plugin

Modern browsers can now load ES modules, which means smaller and faster code!

This plugin allows compiling different versions of JavaScript files with Babel, so you can serve older browsers backwards compatable code with your ES modules.

## Installation

npm:

```sh
npm install --save-dev @chiffon/babel-webpack-plugin
```

yarn:

```sh
yarn add --dev @chiffon/babel-webpack-plugin
```

## Usage

In your webpack config:

```js
const BabelWebpackPlugin = require('@chiffon/babel-webpack-plugin');

module.exports = {
  ...
  module: {
    rules: [
      {
        test: /\.(js|mjs|ts)x?$/,
        use: BabelWebpackPlugin.loader // instead of 'babel-loader'
      },
      ...
    ]
  },
  plugins: [
    new BabelWebpackPlugin({
      targets: [
        {
          target: 'client-legacy',
          excludedPlugins: [],
        },
          target: 'client-modern',
          filename: '[name].[contenthash].mjs',
          chunkFilename: '[name].[contenthash].mjs',
          excludedPlugins: [],
        },
        ...
      ]
    })
    ...
  ]
};
```

@chiffon/babel-webpack-plugin will pass the value of `target` to babel, which you can use like so:

In babel.config.js:

```js
function getBabelWebpackPluginTarget(caller) {
  return caller && caller.target
}

module.exports = function(api) {
  const pluginTarget = api.caller(getBabelWebpackPluginTarget)
  const isModernClient = pluginTarget === 'client-modern'
  const isLegacyClient = pluginTarget === 'client-legacy'

  const presetEnvConfig = {
    modules: isModernClient ? false : 'commonjs',
    targets: { node: 'current' },
  }

  // when pluginTarget is specified, we change preset-env's targets to browsers
  if (isModernClient) {
    presetEnvConfig.targets = { esmodules: true }
  } else if (isLegacyClient) {
    presetEnvConfig.targets = '> 0.25%, not dead'
  }

  return {
    presets: [['@babel/preset-env', presetEnvConfig]],
  }
}
```

Webpack will then build both `index.js` and `index.mjs`.

## FAQ

### What browsers can use ES modules?

All major modern browsers support loading ES modules via the `<script type="module>` tag. [caniuse.com](https://caniuse.com/#feat=es6-module)

### What benefits are there to ES modules?

Since modern browsers also support features like arrow functions, Map, Set and more, there is no need to polyfill or transform those code. This results in a JavaScript bundle that is smaller and faster to download and parse.

### Why compile two or more version?

Older browsers do not understand ES modules, so we still must compile ES5 code in order to provide backwards compatability.

Additionally, you can compile another version for browsers support async/await syntax and get smaller file sizes.

Jason Miller, creator of Preact, explains the various techniques you can apply at https://jasonformat.com/modern-script-loading/.

## References and Further Reading

- [@babel/preset-env targets.esmodules](https://babeljs.io/docs/en/babel-preset-env#targetsesmodules)
- [Jake Archibald: ECMAScript Modules in browsers](https://jakearchibald.com/2017/es-modules-in-browsers/)
- [Modern Script Loading](https://jasonformat.com/modern-script-loading/)
- [freeCodeCamp: using ECMAScript modules](https://www.freecodecamp.org/news/how-to-use-ecmascript-modules-to-build-modular-components-in-javascript-9023205ea42a/)

---
_Source: https://npm.io/package/@chiffon/babel-webpack-plugin · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._