webpack.dev.js

const path = require('path');
const webpack = require('webpack');

module.exports = {
  entry: {
    app: ['babel-polyfill', 'react-hot-loader/patch', './src/index']
  },
  output: {
    path: path.resolve(__dirname, './dist'),
    publicPath: 'dist',
    filename: '[name].js'
  },
  devtool: 'eval',
  devServer: {
    hot: true,
    watchOptions: {
      ignored: /node_modules/
    }
  },
  module: {
    rules: [
      { test: /\.js?$/, exclude: /node_modules/, loader: 'babel-loader' },
      {
        test: /\.scss$/,
        use: [
          'style-loader',
          {
            loader: 'css-loader',
            options: {
              modules: false,
              sourceMap: true,
              importLoaders: 1
            }
          },
          { loader: 'postcss-loader', options: { sourceMap: true } },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: true
            }
          }
        ]
      },
      {
        test: /\.css$/,
        use: [
          'style-loader',
          {
            loader: 'css-loader',
            options: {
              modules: false,
              sourceMap: true
            }
          }
        ]
      }
    ]
  },
  plugins: [
    new webpack.HotModuleReplacementPlugin(),
    new webpack.DefinePlugin({
      'process.env': {
        NODE_ENV: JSON.stringify('development'),
        API_URL: JSON.stringify(process.env.API_URL)
      }
    })
  ]
};