Webpack Multiple Entry Points

webpack.config.babel.js

import webpack from "webpack";
import ExtractTextPlugin from "extract-text-webpack-plugin";
import CopyWebpackPlugin from "copy-webpack-plugin";
import WebpackNotifierPlugin from "webpack-notifier";

const commonCss = `${__dirname}/web/static/css/common`;

const extractSass = new ExtractTextPlugin({
  filename: "css/[name].css",
});

export default {
  entry: {
    app: ["./web/static/css/app/app.scss", "./web/static/js/app.js"],
    support: [
      "./web/static/css/support/support.scss",
      "./web/static/js/support.js",
    ],
  },
  output: {
    path: `${__dirname}/priv/static`,
    filename: "./js/[name].js",
    publicPath: "/",
  },

  resolve: {
    modules: ["node_modules", `${__dirname}/web/static/js`],
  },

  module: {
    loaders: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: "babel-loader",
        include: __dirname,
      },
      {
        test: /\.css$/,
        use: [
          "style-loader",
          {
            loader: "css-loader",
            options: {
              includePaths: [`${__dirname}/node_modules`, commonCss],
              sourceMap: true,
            },
          },
        ],
      },
      {
        test: /\.scss$/,
        use: extractSass.extract({
          use: [
            {
              loader: "css-loader",
              options: {
                includePaths: [`${__dirname}/node_modules`, commonCss],
                sourceMap: true,
              },
            },
            "resolve-url-loader",
            {
              loader: "sass-loader",
              options: {
                includePaths: [`${__dirname}/node_modules`],
                sourceMap: true,
              },
            },
          ],
          fallback: "style-loader",
        }),
      },
      {
        test: /\.(eot|svg|ttf|woff|woff2)$/,
        loader: "file-loader",
        options: {
          name: "[name].[ext]",
          outputPath: "../static/fonts/",
          publicPath: "../fonts/",
        },
      },
      {
        test: /\.(jpg|png|gif)$/,
        loader: "file-loader",
        options: {
          name: "[name].[ext]",
          outputPath: "../static/images/",
          publicPath: "../images/",
        },
      },
    ],
  },
  plugins: [
    new CopyWebpackPlugin([
      {
        from: `${__dirname}/web/static/assets`,
        to: `${__dirname}/priv/static/`,
        ignore: [".DS_Store"],
      },
    ]),
    new WebpackNotifierPlugin(),
    new webpack.ProvidePlugin({
      $: "jquery",
      jQuery: "jquery",
      "window.jQuery": "jquery",
    }),
    extractSass,
  ],
};

Check https://gist.github.com/praveenperera/3bb27ac7f7f895c6665a9b6946dec268 for full instructions