Excluding node_modules from webpack build

webpack.config.js

var Fs = require('fs')
var nodeModules = {}
Fs.readdirSync('node_modules').forEach(function (module) {
  if (module !== '.bin') {
    nodeModules[module] = true
  }
})
var nodeModulesTransform = function(context, request, callback) {
  // search for a '/' indicating a nested module
  var slashIndex = request.indexOf("/");
  var rootModuleName;
  if (slashIndex == -1) {
    rootModuleName = request;
  } else {
    rootModuleName = request.substr(0, slashIndex);
  }

  // Match for root modules that are in our node_modules
  if (nodeModules.hasOwnProperty(rootModuleName)) {
    callback(null, "commonjs " + request);
  } else {
    callback();
  }
}

module.exports = {
  target: 'node',
  entry: './src/server.js',
  output: {
    filename: "./build/server.js"
  },
  externals: nodeModulesTransform,
  module: {
    loaders: [
      {
        loader: 'babel',
        test: /\.js$/,
        exclude: /node_modules/,
        query: {
          presets: ['es2015', 'react']
        }
      }
    ]
  },
  devtool: 'source-map'
}

Hi,

Thanks for the code, I tried it and there are couple of issues with it:

1. There is an error message on the client side saying "require not found", the thing
   is that "webpack-hot-middleware" gets excluded from bundle.js and it should probably be in it.
2. The function "nodeModulesTransform" determines about inclusion/exclusion of modules based on
   their names, however the module name should be check along with its context since webpack
   checks a dependency tree and the function is invoked for modules which are in different directories then
   the root. This didn't cause a bug on my test app but the code should be changed.

I ended up with a code I saw in one of the threads and it worked fine for me:
fs.readdirSync('node_modules')
.forEach(function(moduleName) {
if (moduleName !== '.bin') nodeModules[moduleName] = 'commonjs ' + moduleName;
});

Thanks,
Zohar