Webpack and Express - Critical Dependencies Warning

Question

I have the following webpack.config.ts:

var webpack = require( 'webpack' );
var path = require( 'path' );

module.exports = {

  entry: [
    './api/bin/www.ts'
  ],
  output: {
    path: path.resolve( __dirname, './dist/api' ),
    filename: 'index.js'
  },
  module: {
    loaders: [
      { test: /\.ts$/, loader: 'awesome-typescript-loader' },
      { test: /\.json$/, loader: 'json-loader' }
    ]
  },
  resolve: {
    extensions: [ '', '.js', '.ts' ]
  },
  target: 'node',
  node: {
    console: true,
    fs: 'empty',
    net: 'empty',
    tls: 'empty'
  }
};

When I run webpack I get a warning about a dependency:

WARNING in ./~/express/lib/view.js
Critical dependencies:
78:29-56 the request of a dependency is an expression
@ ./~/express/lib/view.js 78:29-56

The express server I start with this is no more than a Hello World example and functions as should but I am concerned about this warning.

My googlefu hasn't revealed any passable solutions. I have seen one particular instance of this problem but the solutions were to bypass the warning by not showing it.

Answer 1

Use webpack-node-externals.

const nodeExternals = require('webpack-node-externals');

{
  target: 'node',
  externals: [nodeExternals()],
}

https://www.npmjs.com/package/webpack-node-externals

Answer 2

For those that only need to remove the express due to the view lib as mentioned here you can also explicitly target express in externals from your webpack config.

externals: [{ 'express': { commonjs: 'express' } }]

Answer 3

My warning only got fixed with:

module.exports =
{
    target: 'node',
    externals: {
        "express": "require('express')"
    }
}