JSON.stringify broken on Firefox

firefox-stringify-bug.js

var obj = { foo: function () { return "bar"; } };

var jsonString = JSON.stringify(obj, function (key, value) {
  if (typeof value == 'function') {
    return value();
  }
  return value;
});

// Firefox <= 3.6, produces invalid JSON: '{"foo":}'
// Fortunately, this has been fixed on latest Firefox 4 builds
try {
  obj = JSON.parse(jsonString);
} catch (e) {
  console.log(jsonString, e);
}