nodejs serialport Get the number of bytes in the input buffer

[Abib-web]

hello

I listen to a port in real time, I use the nodejs serialport module, but I use the same port to send other information. I use this following code which prevents me from using the port:

port.on('readable', function () {
                if(port.read() === "h"){
             
        }
})

I was thinking of something like checking the number of bytes in the buffer like in python serialport and arduino, the objective is to avoid blocking the port as the previous code does.

I was thinking of using port.read() to evaluate the buffer bits but it always returns null .

if (port.read() > 0){
    //read data
}