Angular Pre-render

index.ts

import 'reflect-metadata';
// Load zone.js for the server.
import 'zone.js/dist/zone-node';
import { enableProdMode } from '@angular/core';
import { renderModuleFactory } from '@angular/platform-server';
// Import module map for lazy loading
import { provideModuleMap } from '@nguniversal/module-map-ngfactory-loader';
import { existsSync, mkdirSync, readFileSync, writeFileSync } from 'fs';
import { join } from 'path';

import { ROUTES } from './prerender.routes';

enum CONFIG {
  srcApp = 'name-of-app-to-prerender-from-angular-json',
  staticApp = 'name-of-static-output-directory',
  serverApp = 'name-of-server-module-output-directory',
}

// Faster server renders w/ Prod mode (dev mode never needed)
enableProdMode();

const BROWSER_FOLDER = join(process.cwd(), 'dist', CONFIG.staticApp);

// Load the index.html file containing references to your application bundle.
const indexPath = join('dist', CONFIG.srcApp, 'index.html');

async function render(routes: string[], browserFolder: string, serverApp: string) {
  const {
    AppServerModuleNgFactory,
    LAZY_MODULE_MAP,
  } = await import(`../../dist/${serverApp}/main`);

  let previousRender = Promise.resolve();

  routes.forEach(route => {
    const fullPath = join(browserFolder, route);

    // Make sure the directory structure is there
    if (!existsSync(fullPath)) {
      mkdirSync(fullPath);
    }

    // Writes rendered HTML to index.html, replacing the file if it already exists.
    previousRender = previousRender
      .then(_ =>
        renderModuleFactory(AppServerModuleNgFactory, {
          document: readFileSync(indexPath, 'utf8'),
          url: route,
          extraProviders: [provideModuleMap(LAZY_MODULE_MAP)],
        }),
      )
      .then(html => writeFileSync(join(fullPath, 'index.html'), html));
  });

}

render(ROUTES.staticPaths, BROWSER_FOLDER, CONFIG.serverApp);

prerender-routes.ts

export const ROUTES = {
  staticPaths: [
    '/',
    'home',
    'dummy'
  ],
};

tsconfig.json

{
  "extends": "../../tsconfig.json", // extend your base angular tsconfig
  "compilerOptions": {
    "module": "commonjs"
  }
}

I put these in a tools/prerender directory in the main project root then run via ts-node --project tools/prerender/tsconfig.json tools/prerender