WIP Make every serializable type have an implicit NbtName

TODO: Test the default. Document in @NbtName. Types that don't have an explicit `@NbtName` will default to having an empty name. The root name is largely redundant, since Minecraft's implementation entirely discards it and just uses an empty string when writing NBT. Giving all types a default name matches Minecraft's behavior, makes serializing with named NBT formats more straightforward for those who don't care about the NBT name, and makes any (3rd-party) serializable type compatible with named NBT out of the box.
BenWoodworth · Sep 5, 2024 · 5141383 · 5141383
1 parent 349191a
commit 5141383
Show file tree

Hide file tree

Showing 5 changed files with 8 additions and 18 deletions.
diff --git a/src/commonMain/kotlin/NbtFormat.kt b/src/commonMain/kotlin/NbtFormat.kt
@@ -44,7 +44,7 @@ public open class NbtFormat internal constructor(
      */
     public fun <T> decodeFromNbtTag(deserializer: DeserializationStrategy<T>, tag: NbtTag): T {
         val context = SerializationNbtContext()
-        val reader = TreeNbtReader(NbtNamed(deserializer.descriptor.nbtName ?: "", tag)) // TODO Propagate NbtNamed
+        val reader = TreeNbtReader(NbtNamed(deserializer.descriptor.nbtName, tag)) // TODO Propagate NbtNamed
         val decoder = NbtReaderDecoder(this, context, reader)
 
         return decoder.decodeSerializableValue(deserializer)

diff --git a/src/commonMain/kotlin/internal/NbtReaderDecoder.kt b/src/commonMain/kotlin/internal/NbtReaderDecoder.kt
@@ -50,10 +50,6 @@ internal abstract class BaseNbtDecoder : AbstractNbtDecoder() {
         if (!nbt.capabilities.namedRoot || !context.isSerializingRootValue) return // No need to verify
 
         val name = descriptor.nbtName
-        if (name == null) {
-            throw NbtException(context, "The ${nbt.name} format requires root values to have an NbtName")
-        }
-
         if (name != decodedTagName && !descriptor.nbtNameIsDynamic) {
             throw NbtDecodingException(context, "Expected tag named '$name', but got '$decodedTagName'")
         }

diff --git a/src/commonMain/kotlin/internal/NbtWriterEncoder.kt b/src/commonMain/kotlin/internal/NbtWriterEncoder.kt
@@ -61,13 +61,8 @@ internal class NbtWriterEncoder(
     private fun beginEncodingValue(type: NbtTagType) {
         when (val structureType = structureTypeStack.lastOrNull()) {
             null -> {
-                val name = nbtNameToWrite
-
-                if (name == null && nbt.capabilities.namedRoot) {
-                    throw NbtException(context, "The ${nbt.name} format requires root values to have an NbtName")
-                }
-
-                writer.beginRootTag(type, name ?: "")
+                val name = checkNotNull(nbtNameToWrite) { "${::nbtNameToWrite.name} was not set" }
+                writer.beginRootTag(type, name)
             }
 
             TAG_Compound -> {

diff --git a/src/commonMain/kotlin/internal/SerialDescriptor.kt b/src/commonMain/kotlin/internal/SerialDescriptor.kt
@@ -43,12 +43,11 @@ internal fun SerialDescriptor.getElementNbtListKind(context: NbtContext, index:
 
 
 @OptIn(ExperimentalSerializationApi::class)
-internal val SerialDescriptor.nbtName: String?
+internal val SerialDescriptor.nbtName: String
     get() = annotations
         .firstOrNull { it is NbtName }
         ?.let { it as NbtName }
-        ?.name
-        ?: "".takeIf { nbtNameIsDynamic } // TODO Remove later?
+        ?.name ?: ""
 
 
 @OptIn(ExperimentalSerializationApi::class, ExperimentalNbtApi::class)

diff --git a/src/commonTest/kotlin/NbtNameTest.kt b/src/commonTest/kotlin/NbtNameTest.kt
@@ -145,7 +145,7 @@ class NbtNameTest {
             .filter { it.capabilities.namedRoot }
 
         val value by parameter(valuesWithStaticNbtNames)
-        val name = value.serializer.descriptor.nbtName!!
+        val name = value.serializer.descriptor.nbtName
 
         val differentlyNamedNbtTag = buildNbtCompound("different_than_$name") {
             // No elements, since the decoder should fail before reaching this point anyway
@@ -235,7 +235,7 @@ class NbtNameTest {
         val serializableType by parameterOfSerializableTypeEdgeCases()
 
         val serializer = DynamicNameWithoutDynamicAnnotationSerializer(serializableType)
-        val nbtName = requireNotNull(serializer.descriptor.nbtName) { "Serializer nbtName is null" }
+        val nbtName = serializer.descriptor.nbtName
 
         val failure = assertFailsWith<IllegalArgumentException> {
             nbt.verifyEncoderOrDecoder(
@@ -269,7 +269,7 @@ class NbtNameTest {
                 decoder.decodeSerializableValue(delegate)
         }
 
-        val nbtName = requireNotNull(serializer.descriptor.nbtName) { "Serializer nbtName is null" }
+        val nbtName = serializer.descriptor.nbtName
 
         val failure = assertFailsWith<IllegalArgumentException> {
             nbt.verifyEncoderOrDecoder(