mithril-vndb/docs/es6.md

ES6

Mithril is written in ES5, and is fully compatible with ES6 as well.

In some limited environments, it's possible to use a significant subset of ES6 directly without extra tooling (for example, in internal applications that do not support IE). However, for the vast majority of use cases, a compiler toolchain like Babel is required to compile ES6 features down to ES5.

Setup

The simplest way to setup an ES6 compilation toolchain is via Babel. To install, use this command:

npm install babel-cli babel-preset-es2015 transform-react-jsx --save-dev

Create a .babelrc file:

{
  "presets": ["es2015"],
  "plugins": [
    ["transform-react-jsx", {
      "pragma": "m"
    }]
  ]
}

To run Babel as a standalone tool, run this from the command line:

babel src --out-dir lib --source-maps

Using Babel with Webpack

If you're using Webpack as a bundler, you can integrate Babel to Webpack, however this requires some additional dependencies, in addition to the steps above.

npm install babel-core babel-loader --save-dev

Create a file called .webpack.config

module.exports = {
    entry: './src/index.js',
    output: {
        path: './bin',
        filename: 'app.js',
    },
    module: {
        loaders: [{
            test: /\.js$/,
            exclude: /node_modules/,
            loader: 'babel-loader'
        }]
    }
}

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Custom setups

If you're using Webpack, you can follow its excellent guide to add support for ES6

If you want to use Babel as a standalone tool, here's the instructions for how to set it up.

Google closure compiler is another tool that supports ES6 to ES5 compilation.