Webpack node_modules externals

Webpack allows you to define externals - modules that should not be bundled.

When bundling with Webpack for the backend - you usually wouldn't want to bundle its node_modules dependencies. This library creates an externals function that ignores node_modules when bundling in Webpack.

Quick usage

npm install webpack-node-externals --save-dev

In your webpack.config.js:

var nodeExternals = require('webpack-node-externals');
...
module.exports = {
    ...
    target: 'node', // in order to ignore built-in modules like path, fs, etc.
    externals: [nodeExternals()], // in order to ignore all modules in node_modules folder
    ...
};

Detailed overview

Description

This library scans the node_modules folder for all node_modules names, and builds an externals function that tells Webpack not to bundle those modules, or any sub-modules of theirs.

Configuration

This library accepts an options object:

var nodeExternals = require('webpack-node-externals');
// in the webpack config:
{
    externals: [nodeExternals(options)]
}

• options.whitelist (=[])

An array of paths for the externals to whitelist, so they will be included in the bundle.

• options.importType (='commonjs')

The method in which unbundled modules will be required in the code. Best to leave as commonjs for node modules.

• options.modulesDir (='node_modules')

The folder in which to search for the node modules.

• Example

  var nodeExternals = require('webpack-node-externals');
  ...
  module.exports = {
      ...
      target: 'node', // important in order not to bundle built-in modules like path, fs, etc.
      externals: [nodeExternals({
          whitelist: ['jquery', 'webpack/hot/dev-server'] // this WILL include `jquery` and `webpack/hot/dev-server` in the bundle
      })],
      ...
  };

Test

npm run test

Q&A

Why not just use a regex in the Webpack config?

Webpack allows inserting regex in the externals array, to capture non-relative modules:

{
    externals: [
        // Every non-relative module is external
        // abc -> require("abc")
        /^[a-z\-0-9]+$/
    ]
}

However, this will leave unbundled all non-relative requires, so it does not account for aliases that may be defined in webpack itself. This library scans the node_modules folder, so it only leaves unbundled the actual node modules that are being used.

License

MIT