What's the status on null values in protobuf right...

# serialization

[Paul Woitaschek]

What's the status on null values in protobuf right now? If I get it correctly protobuf 3 is capable of null values?

[gildor]

Isn’t all values in protobuf are essentially nullable (the only way to support full backward compatibility)?

[gildor]

they can be non-nullable only if have default value

[gildor]

Is it Proto2 or 3?

[Paul Woitaschek]

It's just the serialization library?

[gildor]

What do you mean? Null is supported in general

[gildor]

I clearly see proto annotation on data class

[gildor]

So you serialize/desereali3 it into Proto2?

[Paul Woitaschek]

Don't get it. How would I specify that?

[gildor]

As I know officially it supports Proto2 only

[gildor]

It proto3 may work, just not sure

[gildor]

Could you show whole stacktrace

[Paul Woitaschek]

Sure, but its completely self contained so you can just run it yourself:

Exception in thread "main" kotlinx.serialization.SerializationException: null is not supported
	at kotlinx.serialization.internal.TaggedEncoder.encodeTaggedNull(Tagged.kt:37)
	at kotlinx.serialization.internal.TaggedEncoder.encodeNull(Tagged.kt:71)
	at kotlinx.serialization.Encoder$DefaultImpls.encodeNullableSerializableValue(Encoding.kt:260)
	at kotlinx.serialization.internal.TaggedEncoder.encodeNullableSerializableValue(Tagged.kt:22)
	at kotlinx.serialization.internal.TaggedEncoder.encodeNullableSerializableElement(Tagged.kt:124)
	at Test.write$Self(protobug.kt)
	at Test$$serializer.serialize(protobug.kt)
	at Test$$serializer.serialize(protobug.kt:9)
	at kotlinx.serialization.protobuf.ProtoBuf$ProtobufWriter.encodeSerializableValue(ProtoBuf.kt:148)
	at kotlinx.serialization.EncodingKt.encode(Encoding.kt:402)
	at kotlinx.serialization.protobuf.ProtoBuf.dump(ProtoBuf.kt:541)
	at kotlinx.serialization.protobuf.ProtoBuf$Default.dump(ProtoBuf.kt)
	at ProtobugKt.main(protobug.kt:14)
	at ProtobugKt.main(protobug.kt)

[gildor]

You should enable nulls:

ProtoBuf(encodeDefaults = false)

[gildor]

Essentially protobuf doesn’t have concept of null, only optional with default value, so this flag just skip serialization of this null value