I can define a serializer for a class in many plac...

# serialization

[Adam S]

I can define a serializer for a class in many places. On the class with @Serializable, on the field, for a whole file, in multiple ways with a SerializersModules, and there's also reflection.

Is the order of priority defined somewhere?

I'm asking because I want to see how to override a serializer that's defined on a class with @Serializable(with = ...), and it's not clear in which order serializers are considered and selected.

[ephemient]

SerializersModule can only affect @Contextual and @Polymorphic serialization (additionally, @file:UseContextualSerializers is @Contextual on everything). @Serializable(with = ) on a property overrides @file:UseSerializers overrides the type's own serializer.

[ephemient]

https://kotlin.github.io/kotlinx.serialization/kotlinx-serialization-core/kotlinx.serialization/-use-serializers/index.html

Serializers from this list have higher priority than default, but lesser priority than serializers defined on the property itself, such as Serializable (with=...) or Contextual.

[ephemient]

if by reflection you mean top-level serializer(KType) and similar, that doesn't have access to SerializersModule, so there's only one thing it can possibly do. SerializersModule.serializer(KType) is documented to look up from the module first with fallback: https://kotlin.github.io/kotlinx.serialization/kotlinx-serialization-core/kotlinx.serialization/serializer.html