webpack.config.js

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

module.exports = {
  context: __dirname,
  entry: {
    "charting": "./index.js"
  },
  output: {
    path: path.join(__dirname, "/dist"),
    filename: "[name].js",
    libraryTarget: "umd",
    library: "charting"
  },
  externals: {
    "d3": "d3",
    "crossfilter": {
      "commonjs": "crossfilter",
      "commonjs2": "crossfilter",
      "amd": "crossfilter",
    }
  },
  module: {
    loaders: [
      {
        test: /\.js?$/,
        exclude: /node_modules/,
        use: "babel-loader"
      },
      {
        test: /\.css$/,
        use: ExtractTextPlugin.extract({
          fallback: "style-loader",
          use: "css-loader"
        })
      },
      {
        test: /\.scss$/,
        use: ExtractTextPlugin.extract({
          fallback: "style-loader",
          use: ["css-loader", "sass-loader"]
        })
      }
    ]
  },
  plugins: [
    new webpack.DefinePlugin({
      "process.env": {
        NODE_ENV: JSON.stringify("production")
      }
    }),
    new ExtractTextPlugin("charting.css"),
  ]
};