webpack.config.js

var path = require('path');
var webpack = require('webpack');
const ExtractTextPlugin = require("extract-text-webpack-plugin");
const autoprefixer = require('autoprefixer');

module.exports = {
    entry: './App.js',
    output: {path: __dirname, filename: 'bundle.js'},
    devtool: 'inline-source-map',
    module: {
        rules: [
            {
                test: /\.less$/,
                use: ExtractTextPlugin.extract({
                    fallbackLoader: 'style-loader',
                    loader: [
                        {
                            loader: 'css-loader'
                        },
                        {
                            loader: 'postcss-loader',
                            options: { plugins: () => [autoprefixer] }
                        },
                        {
                            loader: 'less-loader'
                        }
                    ]
                })
            },
            {
                test: /\.(js|jsx)$/,
                use: [
                    {
                        loader: 'babel-loader',
                        options: {
                            presets: ['es2015', 'react']
                        }
                    }
                ],
                exclude: /node_modules/
            },
        ]
    },
    plugins: [
        new ExtractTextPlugin({
            filename: 'style.css',
            allChunks: true
        })
    ],
};