webpack-firebase-fix.js

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

const regex = /firebase\/(app|firestore)/;

module.exports = {
  mode: 'none',
  entry: {
    // This is our Express server for Dynamic universal
    server: './server.ts'
  },
  target: 'node',
  resolve: { extensions: ['.ts', '.js'] },
  optimization: {
    minimize: false
  },
  output: {
    // Puts the output at the root of the dist folder
    path: path.join(__dirname, 'dist'),
    filename: '[name].js',
    libraryTarget: 'umd',
    library: 'app'
  },
   // this makes sure we include node_modules and other 3rd party libraries
  externals: [function(context, request, callback) {

    // exclude firebase products from being bundled, so they will be loaded using require() at runtime.
    if(regex.test(request)) {
      return callback(null, 'commonjs ' + request);
    }
    callback();
  }],
  module: {
    rules: [
      { test: /\.ts$/, loader: 'ts-loader' },
      {
        // Mark files inside `@angular/core` as using SystemJS style dynamic imports.
        // Removing this will cause deprecation warnings to appear.
        test: /(\\|\/)@angular(\\|\/)core(\\|\/).+\.js$/,
        parser: { system: true },
      },
    ]
  },
  plugins: [
    new webpack.ContextReplacementPlugin(
      // fixes WARNING Critical dependency: the request of a dependency is an expression
      /(.+)?angular(\\|\/)core(.+)?/,
      path.join(__dirname, 'src'), // location of your src
      {} // a map of your routes
    ),
    new webpack.ContextReplacementPlugin(
      // fixes WARNING Critical dependency: the request of a dependency is an expression
      /(.+)?express(\\|\/)(.+)?/,
      path.join(__dirname, 'src'),
      {}
    )
  ]
};