Module not found: Error: Cannot resolve module 'server'

Question

I try to use webpack for managing files in my project. I use webpack-dev-server and bower-webpack-plugin. When I run server, I get error in browser console.

Module not found: Error: Cannot resolve module 'server'

webpack.config.js

const BowerWebpackPlugin = require("bower-webpack-plugin");

module.exports = {
    entry: './src/script/index.jsx',
    output: {
        filename: 'bundle.js', //this is the default name, so you can skip it
        //at this directory our bundle file will be available
        //make sure port 8090 is used when launching webpack-dev-server
        publicPath: 'http://localhost:8090/assets'
    },
    devtool: 'source-map',
    module: {
        loaders: [
            {   
                test: /\.js[x]?$/, 
                loaders: ['react-hot', 'jsx', 'babel'],
                exclude: /node_modules/ 
              },
              {
                test: /\.scss$/,
                loaders: [ 'style', 'css?sourceMap', 'sass?sourceMap' ]
              }
        ]
    },
    plugins: [
        new BowerWebpackPlugin()
    ],
    externals: {
        //don't bundle the 'react' npm package with our bundle.js
        //but get it from a global 'React' variable
        'react': 'React'
    },
    resolve: {
        extensions: ['', '.js', '.jsx'],
        modulesDirectories: ["./src", "node_modules", "bower_components"]
    }
}

Edit: Now I use this webpack config without bower-webpack-plugin

package.json

    {
  "scripts": {
    "start": "npm run serve | npm run dev",
    "serve": "./node_modules/.bin/http-server -p 8080",
    "dev": "webpack-dev-server --progress --colors --port 8090"
  },
  "name": "Wonder",
  "version": "0.0.0",
  "description": "Internal app",
  "main": "./src/script/index.jsx",
  "author": "and",
  "license": "ISC",
  "devDependencies": {
    "babel-core": "^5.8.22",
    "babel-loader": "^5.3.2",
    "bower-webpack-plugin": "^0.1.8",
    "css-loader": "^0.16.0",
    "extract-text-webpack-plugin": "^0.8.2",
    "http-server": "^0.8.0",
    "jsx-loader": "^0.13.2",
    "node-sass": "^3.2.0",
    "path": "^0.11.14",
    "react": "^0.13.3",
    "react-hot-loader": "^2.0.0-alpha-2",
    "reinstall": "^1.1.0",
    "sass-loader": "^2.0.1",
    "style-loader": "^0.12.3",
    "webpack": "^1.11.0",
    "webpack-dev-server": "^1.10.1"
  }
}

browser console output

    Uncaught Error: Cannot find module "server"
webpackMissingModule @ bootstrap 19214e8f07aa8a69f314:39
(anonymous function) @ bootstrap 19214e8f07aa8a69f314:39
__webpack_require__ @ bootstrap 19214e8f07aa8a69f314:19
(anonymous function) @ bootstrap 19214e8f07aa8a69f314:39
(anonymous function) @ bootstrap 19214e8f07aa8a69f314:39
webpack-dev-server.js:1 [WDS] Errors while compiling.

    webpack-dev-server.js:1 multi main
    Module not found: Error: Cannot resolve module 'server' in /Users/and/devel/webpack_test
    resolve module server in /Users/and/devel/webpack_test
      looking for modules in /Users/and/devel/webpack_test/src
        /Users/and/devel/webpack_test/src/server doesn't exist (module as directory)
        resolve 'file' server in /Users/and/devel/webpack_test/src
          resolve file
            /Users/and/devel/webpack_test/src/server.js doesn't exist
            /Users/and/devel/webpack_test/src/server doesn't exist
            /Users/and/devel/webpack_test/src/server.jsx doesn't exist
      looking for modules in /Users/and/devel/webpack_test/node_modules
        /Users/and/devel/webpack_test/node_modules/server doesn't exist (module as directory)
        resolve 'file' server in /Users/and/devel/webpack_test/node_modules
          resolve file
            /Users/and/devel/webpack_test/node_modules/server doesn't exist
            /Users/and/devel/webpack_test/node_modules/server.js doesn't exist
            /Users/and/devel/webpack_test/node_modules/server.jsx doesn't exist
      looking for modules in /Users/and/devel/webpack_test/bower_components
        /Users/and/devel/webpack_test/bower_components/server doesn't exist (module as directory)
        resolve 'file' server in /Users/and/devel/webpack_test/bower_components
          resolve file
            /Users/and/devel/webpack_test/bower_components/server doesn't exist
            /Users/and/devel/webpack_test/bower_components/server.js doesn't exist
            /Users/and/devel/webpack_test/bower_components/server.jsx doesn't exist
        resolve 'bower component' server manifest files using [bower.json]
          resolve file
            /Users/and/devel/webpack_test/bower_components/server/bower.json doesn't exists
            /Users/and/devel/webpack_test/src/server/bower.json doesn't exists
            /Users/and/devel/webpack_test/node_modules/server/bower.json doesn't exists
            /Users/and/devel/bower_components/server/bower.json doesn't exists
            /Users/and/devel/src/server/bower.json doesn't exists
            /Users/and/devel/node_modules/server/bower.json doesn't exists
            /Users/and/bower_components/server/bower.json doesn't exists
            /Users/and/src/server/bower.json doesn't exists
            /Users/and/node_modules/server/bower.json doesn't exists
            /Users/bower_components/server/bower.json doesn't exists
            /Users/src/server/bower.json doesn't exists
            /Users/node_modules/server/bower.json doesn't exists
            /bower_components/server/bower.json doesn't exists
            /src/server/bower.json doesn't exists
            /node_modules/server/bower.json doesn't exists
    [/Users/and/devel/webpack_test/src/server.js]
    [/Users/and/devel/webpack_test/src/server]
    [/Users/and/devel/webpack_test/src/server]
    [/Users/and/devel/webpack_test/src/server.jsx]
    [/Users/and/devel/webpack_test/node_modules/server]
    [/Users/and/devel/webpack_test/node_modules/server]
    [/Users/and/devel/webpack_test/node_modules/server.js]
    [/Users/and/devel/webpack_test/node_modules/server.jsx]
    [/Users/and/devel/webpack_test/bower_components/server]
    [/Users/and/devel/webpack_test/bower_components/server]
    [/Users/and/devel/webpack_test/bower_components/server.js]
    [/Users/and/devel/webpack_test/bower_components/server.jsx]
     @ multi main

(anonymous function) @ webpack-dev-server.js:1
n.emit @ webpack-dev-server.js:1
r.onevent @ webpack-dev-server.js:1
r.onpacket @ webpack-dev-server.js:1
t.exports @ webpack-dev-server.js:1
n.emit @ webpack-dev-server.js:1
r.ondecoded @ webpack-dev-server.js:1
t.exports @ webpack-dev-server.js:1
n.emit @ webpack-dev-server.js:1
s.add @ webpack-dev-server.js:1
r.ondata @ webpack-dev-server.js:1
t.exports @ webpack-dev-server.js:1
n.emit @ webpack-dev-server.js:1
r.onPacket @ webpack-dev-server.js:2
(anonymous function) @ webpack-dev-server.js:1
n.emit @ webpack-dev-server.js:1
r.onPacket @ webpack-dev-server.js:1
r.onData.n @ webpack-dev-server.js:1
(anonymous function) @ webpack-dev-server.js:1
e.decodePayloadAsBinary @ webpack-dev-server.js:1
e.decodePayload @ webpack-dev-server.js:1
r.onData @ webpack-dev-server.js:1
(anonymous function) @ webpack-dev-server.js:2
n.emit @ webpack-dev-server.js:1
i.onData @ webpack-dev-server.js:2
i.onLoad @ webpack-dev-server.js:2
i.create.hasXDR.n.onreadystatechange @ webpack-dev-server.js:2

index.html

<!DOCTYPE html>
<html>
<head>
    <title>Basic Property Grid</title>
    <!-- include react -->
    <script src="./node_modules/react/dist/react-with-addons.js"></script>

</head>
<body>
    <div id="content">
        <!-- this is where the root react component will get rendered -->
    </div>
    <!-- include the webpack-dev-server script so our scripts get reloaded when we make a change -->
    <!-- we'll run the webpack dev server on port 8090, so make sure it is correct -->
    <script src="http://localhost:8090/webpack-dev-server.js"></script>
    <!-- include the bundle that contains all our scripts, produced by webpack -->
    <!-- the bundle is served by the webpack-dev-server, so serve it also from localhost:8090 -->
    <script type="text/javascript" src="http://localhost:8090/assets/bundle.js"></script>

</body>
</html>

bower.json

{
  "name": "Wonder",
  "version": "0.0.0",
  "description": "Internal app",
  "main": "index.html",
  "authors": [
    "And"
  ],
  "license": "MIT",
  "ignore": [
    "**/.*",
    "node_modules",
    "bower_components",
    "test",
    "tests"
  ],
  "devDependencies": {
    "jquery": "~2.1.4"
  }
}

Answer 1

Somewhere in your source files or third-party libraries there is a reference to a resource named server (without any extension). It could be in the form of require('server'). Webpack is trying its best to locate it. It checks different forms of it (e.g. server as a directory, server.js, server.jsx, etc) in various locations but it fails in the end. Try to find out where this reference is.