wp-discourse/admin/discourse-sidebar/webpack.config.js

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

// Set different CSS extraction for editor only and common block styles.
const blockCSSPlugin = new ExtractTextPlugin( {
  filename: './dist/block.css'
} );

// Configuration for the ExtractTextPlugin.
const extractConfig = {
  use: [
    { loader: 'raw-loader' },
    {
      loader: 'postcss-loader',
      options: {
        plugins: [ require( 'autoprefixer' ) ]
      }
    },
    {
      loader: 'sass-loader',
      query: {
        outputStyle:
          'production' === process.env.NODE_ENV ? 'compressed' : 'nested'
      }
    }
  ]
};

module.exports = {
  entry: {
    './dist/block': './src/index.js'
  },
  output: {
    path: path.resolve( __dirname ),
    filename: '[name].js'
  },
  watch: true,
  devtool: 'cheap-eval-source-map',
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /(node_modules|bower_components)/,
        use: {
          loader: 'babel-loader'
        }
      },
      {
        test: /style\.s?css$/,
        use: blockCSSPlugin.extract( extractConfig )
      }
    ]
  },
  plugins: [
    blockCSSPlugin
  ]
};