How to minify ES6 code using Webpack?

Question

I'm using webpack and want to deploy my site. If I minify and bundle my JavaScript code, I've got this error:

Parse error: Unexpected token: name (Button)

Here is my not bundled code:

'use strict';

export class Button { // <-- Error happens on this line
    constructor(translate, rotate, text, textscale = 1) {
        this.position = translate;
        this.rotation = rotate;
        this.text = text;
        this.textscale = textscale;
    }
}

Note in bundled code the keyword export is removed. In development, there are no errors thrown. Here you could find my configuration file of WebPack:

var webpack = require('webpack');

var PROD = true;

module.exports = {
    entry: "./js/entry.js",
    output: {
        path: __dirname,
        filename: PROD ? 'bundle.min.js' : 'bundle.js'
    },
    module: {
        loaders: [
            {
                test: /\.css$/,
                loader: "style-loader!css-loader"
            }
        ]
    },
    plugins: PROD ? [
        new webpack.optimize.UglifyJsPlugin({
            compress: { 
                warnings: false 
            },
            output: {
                comments: false,
            },
        })
    ] : []
};

If I change PROD to false, I've no error, if true I've got error from above. My question is can I enable ES6 in Webpack?

Answer 1

Not sure if you're still looking for an answer to this, but now you can include the beta version of uglifyjs-webpack-plugin as a webpack plugin and it'll use uglify-es which can minify ES6 code.

npm install uglifyjs-webpack-plugin

and then in your webpack.config.js:

const Uglify = require("uglifyjs-webpack-plugin");

module.exports = {
    entry: ...,
    output: ...,
    plugins: [
        new Uglify()
    ]
};