webpack.config.js

/* eslint-env node */
const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');

const isProduction = process.env.NODE_ENV === 'production';

module.exports = {
    entry: {
        main: [
            'babel-polyfill',
            'react',
            'd3',
            './src/index.js',
        ],
    },
    output: {
        filename: '[name]-[hash].js',
        path: path.resolve(__dirname, 'build'),
    },
    plugins: [
        new webpack.NamedModulesPlugin(),
        new webpack.DefinePlugin({
            'process.env': {
                NODE_ENV: JSON.stringify(
                    isProduction ? 'production' : 'development'),
            },
        }),
        new HtmlWebpackPlugin({
            template: './src/index.html',
            filename: 'index.html',
            inject: 'body',
        }),
        new webpack.optimize.OccurrenceOrderPlugin(),
    ],
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: [
                    { loader: 'babel-loader' },
                ],
            },
            {
                test: /\.css$/,
                use: [
                    { loader: 'style-loader' },
                    {
                        loader: 'css-loader',
                        options: {
                            importLoader: 1,
                        },
                    },
                    { loader: 'postcss-loader' },
                ],
            },
        ],
    },
};