And yet another is to raise an exception, which is easy to write but really punts the issue back to the application programmer who will have to decide how to ensure they never pass in a NULL parameter.
That's kinda the point - if they never pass NULL they won't encounter any problems but as soon as the data and their application don't see eye-to-eye the application developer has to decide what they want to do about it. We are in no position to decide for them and making it obvious they have a decision to make and implement here doesn't seem like a improper position to take.
Possibly we could even add an extra parameter to specify what should be done.
Has appeal.
Should we return NULL in those cases as we do now?
Probably the same thing - though I'd accept having the input json being null result in the output json being null as well.
