Res.locals not an javascript Object

[trquoccuong]

Hi . I think res.locals similar with app.locals (javascript Object) But I cant call buildin function hasOwnProperty .
http://stackoverflow.com/questions/32878954/object-javascipt-dont-have-build-in-function-hasownproperty

[dougwilson]

Hi! This is because res.locals is meant to be a bag for you to store key value pairs, meaning it is perfectly OK to do res.locals.hasOwnProperty = 'foo' and everything will still work fine. If you need to call hasOwnProperty on it, you need to do Object.prototype.hasOwnProperty.call(res.locals, 'propName').

[wesleytodd]

Sorry to bring this back up, but I think @trquoccuong's question is important. This is very unexpected behavior IMO. I think we should maybe consider changing this behavior in express 5.0. Is there somewhere this decision was made that I could read over so I understand more?