What I’m trying to achieve here is to listen to a port for incoming data through a ngrok tcp tunnel.
I’m a tester and have very little knowledge on networking.

Can this be achieved using any npm package??

What I did so far:

async function startNcatListener(port) {

  return new Promise((resolve, reject) => {
    let dataReceived = false; // Flag to track whether data has been received

    const ncat = new childProcess.spawn('ncat', ['-nvlp', port]);

    ncat.stdout.on('data', (data) => {
      // Validate incoming data
      console.log('data', data)
        expect(data.toString()).toContain('node@scriptworker'); // Modify 'ExpectedData' to match your   expected data
        dataReceived = true; // Set flag to true when data is received
        resolve(); // Resolve the promise if data is as expected
    });

    ncat.stderr.on('data', (data) => {
        console.error(`ncat stderr: ${data}`);
        reject(new Error(`ncat stderr: ${data}`)); // Reject the promise if there's an error
    });

    ncat.on('close', (code) => {
        console.log(`ncat process exited with code ${code}`);
        if (!dataReceived) {
            reject(new Error('Timeout: No data received within 2 minutes')); // Reject the promise if no data is received within 2 minutes
        }
    });

    ncat.on('error', (err) => {
        console.error('Failed to start ncat process:', err);
        reject(err); // Reject the promise if there's an error
    });

    // Set a timeout to exit if no data is received within 2 minutes
    setTimeout(() => {
        if (!dataReceived) {
            console.log('Timeout: No data received within 2 minutes');
            ncat.kill(); // Kill the ncat process
        }
    }, 2 * 60 * 1000);
});

And yes the code is from chatgpt.

But it throws an error which I’m unable to solve:

  console.error
    ncat stderr: Ncat: Version 7.95 ( https://nmap.org/ncat )
    

      158 |
      159 |     ncat.stderr.on('data', (data) => {
    > 160 |         console.error(`ncat stderr: ${data}`);
          |                 ^
      161 |         reject(new Error(`ncat stderr: ${data}`)); // Reject the promise if there's an error
      162 |     });