webpack.config.js

const Fs = require('fs');
const Path = require('path');

const files = [];
const nodeModules = {};

const getFilesAndSubdirectories = (dir) => {

    Fs.readdirSync(dir)
        .forEach((item) => {

            const fqn = `${dir}/${item}`;
            const fqFileName = fqn.replace('./node_modules/', '');

            const stat = Fs.statSync(fqn);
            if (stat.isDirectory()) {
                files.push(fqFileName);
                getFilesAndSubdirectories(fqn);
            }
            else if (stat.isFile() && Path.extname(fqn).substring(1) === 'js') {
                files.push(fqFileName.replace('.js', ''));
            }
        });
};

getFilesAndSubdirectories('./node_modules');

files.forEach((file) => {
    
    nodeModules[file] = `commonjs ${file}`;
});

// exclude all node modules in config
config.externals = nodeModules;