Hi,

• The types aren't consistent at all: it shouldn't be allowed to declare a node without value
• using any for the values is just.... bad? The first interest in using type is... types values! => the class should be generic
• the description is far from complete:
  • types used as value? (the sample tests makes think that number only are used)
  • default value for next? (not said, not provided, not tested)

cheers

PS: I doubt implementing other data kinds will be more interesting. What you could do on the other hand is translate existing kata about all this in TS, rather than create new ones in TS only.

Declaring and assigning variables is not a novel or interesting kata idea.