To add to the sibling, I've seen this with Java enums a lot. People will add it so that the value is consumed using the enum as fast as they can. This works well as long as the value is not retrieved from data. As soon as you do that, you lose the ability to add to the possible values in a rolling release way. It can be very frustrating to know that we can't push a new producer of a value before we first change all consumers. Even if all consumers already use switch statements with default clauses to exhaustively cover behavior.

▲

thinkharderdev 7 days ago | parent [-]

But this is something you should be able to handle on a case-by-case basis. If you have a type which is stored durably as protobuf then adding required fields is much harder. But if you are just dealing with transient rpc messages then it can be done relatively easily in a two step process. First you add the field as optional and then once all producers are upgraded (and setting the new field), make it required. It's annoying for sure but still seems better than having everything optional always and needing to deal with that in application code everywhere.

▲

taeric 6 days ago | parent [-]

Largely true. If you are at Google scale, odds are you have mixed fleets deployed. Such that it is a bit of involved process. But it is well defined and doable. I think a lot of us would rather not do a dance we don't have to do?

	▲	thinkharderdev 6 days ago \| parent [-]
		Sure, you just have to balance that against the cost of a poorly specified API interface. The errors because clients aren't clear on what is really required or not, what they should consider an error if it is not defined, etc. And of course all the boilerplate code that you have to write to convert the interface model to an internal domain model you can actually use inside your code.