Is it possible to strip undefined properties on encoding?

In the docs it says that both null and undefined will come through as null on the other end. Is it possible to configure something to make undefined properties to be removed completely during encoding?

[simonjeesam]

I went ahead and tried a fix myself based on the work done by @brentd here.

Pull request here.

[scmorse]

IMO it is a bug to have undefined encoded as null. undefined should not be defined in the encoding. Just like with JSON:

> JSON.parse(JSON.stringify({a: undefined}))
{}
> JSON.parse(JSON.stringify({a: undefined})).a
undefined

Yet with this lib:

> msgpack.decode(msgpack.encode({a: undefined}))
{ a: null }
> msgpack.decode(msgpack.encode({a: undefined})).a
null