Hi Charlie, you're right it's a side effect in these specs whether it's actually a Ruby Array.
On the other hand Ruby -> JS translates Array into a JS array but than there's the opposite (JS -> Ruby) conversion as the array comes out into the Ruby world ?
Not sure maybe that should be speced, but as I said you're right these specs should not care whether it's actually a Ruby Array instance ... feel free to change it.
K.