I'm wary of things like this. They tend to require more cognitive effort than either of the alternatives: strict typing or a purist version of duck typing. That

I'm wary of things like this. They tend to require more cognitive effort than either of the alternatives: strict typing or a purist version of duck typing. That javascript makes either of those difficult or impossible (the former for obvious reasons and the latter because of flexible implicit conversion rules and an inflexible message receiver mechanism) is a failing of javascript that can't really be bandaided over with something optional. I just think that this is, with even the best intentions, extremely prone to bitrot.