--listen accepts any string as port number

[unixwork]

The --listen argument accepts any string as a port, not just a number.

    $ wscat --listen notanumber
    Listening on port notanumber (press CTRL+C to quit)

In this case, wscat creates a Unix domain socket, not a TCP socket. I'm not sure if this is intentional, but at least the output suggests that it may be accidental.