import net from "net";

export function isPortAvailable(port: number): Promise<boolean> {
  return new Promise(resolve => {
    const server = net.createServer();
    server.listen(port, () => {
      server.close(() => resolve(true));
    });
    server.on("error", () => resolve(false));
  });
}

export async function findAvailablePort(startPort: number = 3000): Promise<number> {
  for (let port = startPort; port < startPort + 20; port++) {
    if (await isPortAvailable(port)) {
      return port;
    }
  }
  throw new Error(`No available port found starting from ${startPort}`);
}