const { spawn } = require("child_process");const path = require("path"); const frontendDir = path.resolve(__dirname, "..");const backendLauncher = path.resolve(frontendDir, "..", "start-backend.js");const nextBin = require.resolve("next/dist/bin/next"); /** @type {import("child_process").ChildProcess[]} */const children = []; function start(label, file, args, cwd) {  const child = spawn(file, args, {    cwd,    env: process.env,    stdio: "inherit",    windowsHide: false,  });   child.on("error", (error) => {    console.error(`[${label}] failed to start:`, error);    shutdown(1);  });   child.on("exit", (code, signal) => {    if (signal || (code ?? 0) !== 0) {      console.error(`[${label}] exited with ${signal ?? code}`);      shutdown(typeof code === "number" ? code : 1);      return;    }    shutdown(0);  });   children.push(child);  return child;} let shuttingDown = false; function shutdown(exitCode) {  if (shuttingDown) {    return;  }  shuttingDown = true;  for (const child of children) {    if (!child.killed) {      child.kill();    }  }  process.exit(exitCode);} process.on("SIGINT", () => shutdown(0));process.on("SIGTERM", () => shutdown(0)); start(  "frontend",  process.execPath,  [nextBin, "dev", "--hostname", "127.0.0.1", "--port", "3000"],  frontendDir,);start("backend", process.execPath, [backendLauncher], frontendDir);