start-of-executor.ts

import { ServeFullstackExecutorSchema } from './schema';
import { ExecutorContext } from '@nrwl/devkit';
import { ChildProcess, exec } from 'child_process';

const LARGE_BUFFER = 1024 * 1000000;

export default async function runExecutor(
  options: ServeFullstackExecutorSchema,
  _context: ExecutorContext
) {
  await startBackendServer(options);
}

async function startBackendServer(options: ServeFullstackExecutorSchema) {
  return new Promise(() => {
    const childProcess = exec(`npx nx serve ${options.backendProject}`, {
      maxBuffer: LARGE_BUFFER,
    });
    process.on('exit', () => childProcess.kill());
    process.on('SIGTERM', () => childProcess.kill());
    childProcess.stdout.on('data', (data) => {
      if (data.includes('No errors found.')) {
        // later we'll start our frontend serve here!
      }
    });
  });
}