title: Using webpack-dev-server and Hot Module Replacement not updating bundle.js with changes to JS or SCSS files
body: <p>I am using an npm script <code>npm start</code> to run <code>webpack-dev-server --progress --colors --hot --inline --open</code> in the Terminal. My React app loads up fine on the local server. But when I make any SCSS changes for example I see:</p>
  
  <pre><code>webpack: bundle is now INVALID.
  Hash: 619812c0fa6ffc42708e
  Version: webpack 1.13.3
  Time: 343ms
                                 Asset       Size  Chunks             Chunk Names
                             bundle.js    1.02 MB       0  [emitted]  main
  0.065f433e5a1a691720c9.hot-update.js  659 bytes       0  [emitted]  main
  065f433e5a1a691720c9.hot-update.json   36 bytes          [emitted]
  chunk    {0} bundle.js, 0.065f433e5a1a691720c9.hot-update.js (main) 946 kB [rendered]
    [249] ./~/css-loader?sourceMap!./~/sass-loader?sourceMap!./src/styles/main.scss 586 bytes {0} [built]
       + 251 hidden modules
  webpack: bundle is now VALID.
  </code></pre>
  
  <p>However, the page doesn't reflect any SCSS or JS changes I make. My bundle.js is not updated at all. However, if i run <code>webpack</code> in another Terminal window my bundle.js updates and then if I refresh my page I can see my changes.</p>
  
  <p>Here is my webpack.config.js:</p>
  
  <pre><code>var webpack = require("webpack");
  
  module.exports = {
    entry:  "./src/main.js",
    output: {
      path: "./build/scripts",
      filename: "bundle.js"
    },
    module: {
      loaders: [
        { test: /\.jsx?$/,
          loader: "babel",
          exclude: "./node_modules"
        },
        { test: /\.scss$/,
          loaders: [ "style", "css?sourceMap", "sass?sourceMap" ]
        }
      ],
    }
  };
  </code></pre>
  
  <p>Here is my main.js file:</p>
  
  <pre><code>import React from "react";
  import ReactDOM from "react-dom";
  
  // CSS
  import "./styles/main.scss"
  
  let docBody = "Webpack is doing its thing, with ES2015!!";
  document.write(docBody);
  </code></pre>
  
  <p>Any idea what I'm doing wrong here?</p>