webpack.config.js

const ExtractTextPlugin = require('extract-text-webpack-plugin')
module.exports = {
    module: {
        loaders: [
            {
                test: /\.js/,
                loader: 'babel',
                exclude: /node_modules/,
                query: {
                    plugins: ['transform-decorators-legacy'],
                    presets: ['latest']
                }
            },
            {
                test: /\.less$/,
                loader: ExtractTextPlugin.extract('style-loader', 'css-loader!less-loader')
            }
        ]
    }
}