Webpack dev server not auto-reloading

I had the same issue and the following configuration enabled static and the in-memory bundle auto-reloading. The key is to enable devServer.watchContentBase.

config/webpack.config.dev.js

...
module.exports = {
    ...
    devServer: {
        contentBase: ...,
        publicPath: ...,
        watchContentBase: true
    },
    ...
}

package.json

{
    ...
    "scripts": {
        "develop": "webpack-dev-server --open --mode development --config config/webpack.config.dev.js",
        ...
    }
    ...
}

According to the webpack dev server documentation you should add this entry point to the webpack configuration to support automatic refresh.

config.entry.unshift("webpack-dev-server/client?http://localhost:8080/");

jontem pointed out in his answer that my config was missing a webpack-dev-server client.

Here's the steps I took to apply his solution and also setup HMR.

config/webpack.config.dev.js

module.config = {
  // ...
  entry: [
    // converted entry to an array
    // to allow me to unshift the client later
    path.resolve(__dirname, '../src/index.jsx')
  ],
  // ...
  module: {
    loaders: {
      // ...
      {
        // Use style loader instead of ExtractTextPlugin
        // To allow for style injection / hot reloading css
        exclude: /node_modules/,
        loaders: [ 'style', 'css', 'postcss', 'sass' ],
        test   : /\.scss$/
      },
      // ...
    }
  }
}

---

scripts/dev.js

'use strict';

const WebpackDevServer = require('webpack-dev-server');
const config           = require('../config/webpack.config.dev.js');
const webpack          = require('webpack');

// unshift `webpack-dev-server` client
// and hot dev-server
config.entry.unshift('webpack-dev-server/client?/', 'webpack/hot/dev-server');

const compiler = webpack(config);

// ...