bleistift2Jun 30, 2024

Trying to understand JSON…

https://sopuli.xyz/post/14323503

Trying to understand JSON… - Sopuli

Meme transcription: Panel 1. Two images of JSON, one is the empty object, one is an object in which the key name maps to the value null. Caption: “Corporate needs you to find the difference between this picture and this picture” Panel 2. The Java backend dev answers, “They’re the same picture.”

Show threadExcelJun 30, 2024
If you’re branching logic due to the existence or non-existence of a field rather than the value of a field (or treating undefined different from null), I’m going to say you’re the one doing something wrong, not the Java dev.
Show threadsik0fewlJun 30, 2024
Ya, having null semantics is one thing, but having different null and absent/undefined semantics just seems like a bad idea.
Show threadUsernameJun 30, 2024

Not really, if absent means “no change”, present means “update” and null means “delete” the three values are perfectly well defined.

For what it’s worth, Amazon and Microsoft do it like this in their IoT offerings.

Show threadladJul 1, 2024
Except, if you use any library for deserialization of JSONs there is a chance that it will not distinguish between null and absent, and that will be absolutely standard compliant. This is also an issue with protobuf that inserts default values for plain types and enums. Those standards are just not fit too well for patching
Show threadmasterspace
I’ve never once seen a JSON serializer misjudge null and absent fields, I’ve just seen developers do that.
Jul 1, 2024 at 4:44pmWeb
Show threadladJul 1, 2024

Well, Jackson before 2.9 did not differentiate, and although this was more than five years ago now, this is somewhat of a counter example

Also, you sound like serializers are not made by developers

Show threadmasterspaceJul 2, 2024
Bruh, there’s a difference between the one or two serializing packages used in each language, and the thousands and thousands of developers who miscode contracts after that point.