And also ensure that this is set correctly: http://forum.espruino.com/comments/12223222/

please bear in mind that reassigning exports does not actually export a thing in node.js, that is why people use module.exports = ... instead.

exports = function wut() {};

If we require that file in node the exported value would be just a regular empty object.

In order to actually overwrite the exports you need to overwrite the module property.

module.exports = function wut() {};

Inside a module, and only when required, exports is the equivalent of this

However, in the main file, this will be the global object instead.
An old trick to know if a file is loaded as module is indeed:

function log(s) {
  console.log(s);
}
if (this === global) {
  log('main');
} else {
  module.exports = log;
}

As summary, this is how in JS you would evaluate a module:

function evalRequire(scriptContent) {
  var exports = {};
  var module = {exports: exports};

  Function(
    'global,exports,module',
    scriptContent
  ).call(
    exports,
    global,
    exports,
    module
  );

  return module.exports;
}

As you can see, replacing the exports variable inside the module won't actually affect the exported value, since that's retrieved through the module and exports is simply a shortcut.

node.js has been like this since version 0.4 if I remember correctly, hope this helps.

Thanks, yes, it does. I'm actually pretty sure I added the exports= behaviour at someone's request. Looks like I should have double-checked first!