Webpack dev server not auto-reloading

Question

So I've setup webpack and webpack-dev-server, but webpack-dev-server does not auto-reload. If i modify a file and save it there is no change in the browser until I manually refresh.

Here is my webpack config and my script file that runs webpack-dev-server. Does anyone see anything that could be preventing auto-reload from working?

I put these together by reading through multiple tutorials, the docs, and by reading through the react-create-app generated files.

---

config/webpack.config.dev.js

'use strict';

const ExtractTextPlugin = require('extract-text-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const autoprefixer = require('autoprefixer');
const webpack = require('webpack');

const extractSass = new ExtractTextPlugin('style.css');

module.exports = {
    entry : './src/index.jsx',
    eslint: {configFile: './src/.eslintrc.json'},
    module: {
        loaders: [
            {
                exclude: /node_modules/,
                include: ['src'],
                loader: 'babel',
                test  : /(\.js|\.jsx)$/
            },
            {
                exclude: /node_modules/,
                include: ['src']
                loader : extractSass.extract([ 'css', 'postcss', 'sass' ]),
                test   : /\.scss$/
            }
        ],
        preLoaders: [
            {
                exclude: /node_modules/,
                loader : 'eslint',
                query  : {presets: [ 'react', 'latest' ]},
                test   : /(\.js|\.jsx)$/
            }
        ]
    },
    output: {
        filename  : 'bundle.js',
        path      : 'dist',
        publicPath: '/'
    },
    plugins: [
        extractSass,
        new HtmlWebpackPlugin({
            inject  : true,
            template: paths.appHtml
        }),
        new webpack.HotModuleReplacementPlugin({multistep: true})
    ],
    postcss: () => [
        autoprefixer({
            browsers: [
                '>1%',
                'last 4 versions',
                'Firefox ESR',
                'not ie < 9'
            ]
        })
    ]
};

---

scripts/dev.js

run with $ yarn run dev

'use strict';

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

const compiler = webpack(config);

const server = new WebpackDevServer(compiler, {
    clientLogLevel    : 'warn',
    compress          : true,
    contentBase       : 'public',
    filename          : config.output.filename,
    historyApiFallback: true,
    hot               : true,
    inline            : true,
    lazy              : false,
    noInfo            : true,
    publicPath        : '/',
    quiet             : true,
    stats             : 'errors-only',
    watchOptions      : {
        aggregateTimeout: 300,
        poll            : 1000
    }
});

server.listen(8080, 'localhost', () => {
    console.log('Listening on port 8080');
});

Answer 1

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/");

Answer 2

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);

// ...

Answer 3

Also

1. if you use extract-loader, auto reload will not work
2. Hot Module Replacement feature

devServer: {
    // ,,,
    contentBase: '/your/path'
    watchContentBase: true
    hot: true,
},

prevents refresh your static files in web page, unless you press F5 button in browser

Answer 4

I also had the same issue and after adding this code line my problem solved. Now auto reloading worked

devServer : {
        contentBase : './',
        watchOptions : {
            poll: true
        }
}

Answer 5

I had a similar problem, fixed it by adding

    watchOptions: {
        poll: true
    }

When I first installed the webpack starter, everything worked flawlessly, after a week of changes to webpack.config.js, it stopped working. I tinkered with various recommendations, the one that worked was watchOptions: {poll:true }

FYI I am webpack 4 with "webpack": "4.29.6", "webpack-cli": "^3.3.0", "webpack-dev-server": "3.3.1"

devServer: {
    port: 3000,
    contentBase: './',
     watchOptions: {
        poll: true
    }
}

Answer 6

For anyone experiencing this with Webpack v5, you need to set target to web in your config, like so:

module.exports = {
    entry: "...",
    target: "web",
    .....
}

Answer 7

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",
        ...
    }
    ...
}

Answer 8

Please add the following in your webpack config and try.

devServer: {
        hot: true,
        inline: true,
        host: "localhost",
        port: 8082,
        watchOptions: {
            poll: true
        }
    }

note: I was using webpack version ^3.11.0

Answer 9

This third party webpack dev server documentation has the answer that I needed: https://wohugb.gitbooks.io/webpack/content/dev_tools/webpack-dev-server.html

The relevant section reproduced below:

There is no inline: true flag in the webpack-dev-server configuration, because the webpack-dev-server module has no access to the webpack configuration. Instead the user have to add the webpack-dev-server client entry point to the webpack configuration.

To do this just add webpack-dev-server/client?http://: to (all) entry point(s). I. e. with the above configuration:

var config = require("./webpack.config.js");
config.entry.app.unshift("webpack-dev-server/client?http://localhost:8080");
var compiler = webpack(config);
var server = new webpackDevServer(compiler, {...});
server.listen(8080);