Actually, if the underlying value is null maybe a JSON::Any with a value of nil should be returned. For example:

require "json"

p JSON.parse(%q<{"some": null}>)["some"].class # => JSON::Any

That is, there is a value in that position, it's just null.

I have a fix for this (using Hash#fetch(...) { ... } and Array#at(...) { ... }. I can push it, but I wanted to discuss this first.

i think null should be nil

Yeah, I think the semantic difference is very tiny and returning nil is more convenient in the end