Reading from a socket with GJS (Gnome Shell extension) -- failure to read from Gio.InputStream

[gdfc <gdfc o2 pl>]

Hi!

I'm currently writing an extension for Gnome Shell using gjs and have to read some gpsd data from a socket. I've gotten this far:

            const Gio = imports.gi.Gio;
            let sockCl = new Gio.SocketClient();
            let sockCon = sockCl.connect_to_host("localhost:2947", null, null);
            let outStr = sockCon.get_output_stream();
            outStr.write('?WATCH={"enable":true,"json":true};', null);
            let inStr = sockCon.get_input_stream();
            let b = new Array(128);
            inStr.read(b, 1, null);

However, the read method always fails with the following error:

            Error: Argument 'buffer' (type void) may not be null

I've tried all read* methods described in the only more or less current gjs API reference I've found [1], but they all seem to have the same problem. This is regardless of what type b is -- it can be an array, a string, a number or even a function, but it doesn't get recognised as anything other than null. I'm aware of [2] (this is the only web search result I've stumbled upon), but it is of little help.

So my question here: does anyone know a way to read from a socket in gjs? It doesn't have to be Gio, any standard lib would do... I've tried some Soup and GLib methods, but they don't seem to work either. In Gio, I do at least get the OutputStream to write reliably...

Any advice is highly appreciated. Thank you!

[1] http://www.roojs.com/seed/gir-1.2-gtk-3.0/gjs/Gio.InputStream.html
[2] https://mail.gnome.org/archives/javascript-list/2012-January/msg00003.html