Add shortValueClassHeaderName config (#29)

* Add value class test
* Rename test `EnumClass`
* Add `shortValueClassHeaderName` config
* Update README
* Update API
* Update CHANGELOG

Closes #16

Author: brudaswen

CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Config `shortValueClassHeaderName` for short value class header name.
+- Kotlin Multiplatform support.
+
+### Changed
+
+- Some API changes for Kotlin Multiplatform support.
+
 ## [2.1.1] - 2025-10-01
 
 ### Changed

README.md

@@ -60,6 +60,7 @@ public final class kotlinx/serialization/csv/config/CsvBuilder {
 	public final fun getQuoteMode ()Lkotlinx/serialization/csv/config/QuoteMode;
 	public final fun getRecordSeparator ()Ljava/lang/String;
 	public final fun getSerializersModule ()Lkotlinx/serialization/modules/SerializersModule;
+	public final fun getShortValueClassHeaderName ()Z
 	public final fun setDelimiter (C)V
 	public final fun setEscapeChar (Ljava/lang/Character;)V
 	public final fun setHasHeaderRecord (Z)V
@@ -72,17 +73,19 @@ public final class kotlinx/serialization/csv/config/CsvBuilder {
 	public final fun setQuoteMode (Lkotlinx/serialization/csv/config/QuoteMode;)V
 	public final fun setRecordSeparator (Ljava/lang/String;)V
 	public final fun setSerializersModule (Lkotlinx/serialization/modules/SerializersModule;)V
+	public final fun setShortValueClassHeaderName (Z)V
 }
 
 public final class kotlinx/serialization/csv/config/CsvConfig {
 	public static final field Companion Lkotlinx/serialization/csv/config/CsvConfig$Companion;
 	public fun <init> ()V
-	public fun <init> (CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZLkotlinx/serialization/modules/SerializersModule;)V
-	public synthetic fun <init> (CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZLkotlinx/serialization/modules/SerializersModule;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZZLkotlinx/serialization/modules/SerializersModule;)V
+	public synthetic fun <init> (CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZZLkotlinx/serialization/modules/SerializersModule;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()C
 	public final fun component10 ()Z
 	public final fun component11 ()Z
-	public final fun component12 ()Lkotlinx/serialization/modules/SerializersModule;
+	public final fun component12 ()Z
+	public final fun component13 ()Lkotlinx/serialization/modules/SerializersModule;
 	public final fun component2 ()Ljava/lang/String;
 	public final fun component3 ()C
 	public final fun component4 ()Lkotlinx/serialization/csv/config/QuoteMode;
@@ -91,8 +94,8 @@ public final class kotlinx/serialization/csv/config/CsvConfig {
 	public final fun component7 ()Z
 	public final fun component8 ()Z
 	public final fun component9 ()C
-	public final fun copy (CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZLkotlinx/serialization/modules/SerializersModule;)Lkotlinx/serialization/csv/config/CsvConfig;
-	public static synthetic fun copy$default (Lkotlinx/serialization/csv/config/CsvConfig;CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZLkotlinx/serialization/modules/SerializersModule;ILjava/lang/Object;)Lkotlinx/serialization/csv/config/CsvConfig;
+	public final fun copy (CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZZLkotlinx/serialization/modules/SerializersModule;)Lkotlinx/serialization/csv/config/CsvConfig;
+	public static synthetic fun copy$default (Lkotlinx/serialization/csv/config/CsvConfig;CLjava/lang/String;CLkotlinx/serialization/csv/config/QuoteMode;Ljava/lang/Character;Ljava/lang/String;ZZCZZZLkotlinx/serialization/modules/SerializersModule;ILjava/lang/Object;)Lkotlinx/serialization/csv/config/CsvConfig;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getDelimiter ()C
 	public final fun getEscapeChar ()Ljava/lang/Character;
@@ -106,6 +109,7 @@ public final class kotlinx/serialization/csv/config/CsvConfig {
 	public final fun getQuoteMode ()Lkotlinx/serialization/csv/config/QuoteMode;
 	public final fun getRecordSeparator ()Ljava/lang/String;
 	public final fun getSerializersModule ()Lkotlinx/serialization/modules/SerializersModule;
+	public final fun getShortValueClassHeaderName ()Z
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
 }

library/api/library.api

@@ -82,10 +82,13 @@ final class kotlinx.serialization.csv.config/CsvBuilder { // kotlinx.serializati
     final var serializersModule // kotlinx.serialization.csv.config/CsvBuilder.serializersModule|{}serializersModule[0]
         final fun <get-serializersModule>(): kotlinx.serialization.modules/SerializersModule // kotlinx.serialization.csv.config/CsvBuilder.serializersModule.<get-serializersModule>|<get-serializersModule>(){}[0]
         final fun <set-serializersModule>(kotlinx.serialization.modules/SerializersModule) // kotlinx.serialization.csv.config/CsvBuilder.serializersModule.<set-serializersModule>|<set-serializersModule>(kotlinx.serialization.modules.SerializersModule){}[0]
+    final var shortValueClassHeaderName // kotlinx.serialization.csv.config/CsvBuilder.shortValueClassHeaderName|{}shortValueClassHeaderName[0]
+        final fun <get-shortValueClassHeaderName>(): kotlin/Boolean // kotlinx.serialization.csv.config/CsvBuilder.shortValueClassHeaderName.<get-shortValueClassHeaderName>|<get-shortValueClassHeaderName>(){}[0]
+        final fun <set-shortValueClassHeaderName>(kotlin/Boolean) // kotlinx.serialization.csv.config/CsvBuilder.shortValueClassHeaderName.<set-shortValueClassHeaderName>|<set-shortValueClassHeaderName>(kotlin.Boolean){}[0]
 }
 
 final class kotlinx.serialization.csv.config/CsvConfig { // kotlinx.serialization.csv.config/CsvConfig|null[0]
-    constructor <init>(kotlin/Char = ..., kotlin/String = ..., kotlin/Char = ..., kotlinx.serialization.csv.config/QuoteMode = ..., kotlin/Char? = ..., kotlin/String = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin/Char = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlinx.serialization.modules/SerializersModule = ...) // kotlinx.serialization.csv.config/CsvConfig.<init>|<init>(kotlin.Char;kotlin.String;kotlin.Char;kotlinx.serialization.csv.config.QuoteMode;kotlin.Char?;kotlin.String;kotlin.Boolean;kotlin.Boolean;kotlin.Char;kotlin.Boolean;kotlin.Boolean;kotlinx.serialization.modules.SerializersModule){}[0]
+    constructor <init>(kotlin/Char = ..., kotlin/String = ..., kotlin/Char = ..., kotlinx.serialization.csv.config/QuoteMode = ..., kotlin/Char? = ..., kotlin/String = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin/Char = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlinx.serialization.modules/SerializersModule = ...) // kotlinx.serialization.csv.config/CsvConfig.<init>|<init>(kotlin.Char;kotlin.String;kotlin.Char;kotlinx.serialization.csv.config.QuoteMode;kotlin.Char?;kotlin.String;kotlin.Boolean;kotlin.Boolean;kotlin.Char;kotlin.Boolean;kotlin.Boolean;kotlin.Boolean;kotlinx.serialization.modules.SerializersModule){}[0]
 
     final val delimiter // kotlinx.serialization.csv.config/CsvConfig.delimiter|{}delimiter[0]
         final fun <get-delimiter>(): kotlin/Char // kotlinx.serialization.csv.config/CsvConfig.delimiter.<get-delimiter>|<get-delimiter>(){}[0]
@@ -111,11 +114,14 @@ final class kotlinx.serialization.csv.config/CsvConfig { // kotlinx.serializatio
         final fun <get-recordSeparator>(): kotlin/String // kotlinx.serialization.csv.config/CsvConfig.recordSeparator.<get-recordSeparator>|<get-recordSeparator>(){}[0]
     final val serializersModule // kotlinx.serialization.csv.config/CsvConfig.serializersModule|{}serializersModule[0]
         final fun <get-serializersModule>(): kotlinx.serialization.modules/SerializersModule // kotlinx.serialization.csv.config/CsvConfig.serializersModule.<get-serializersModule>|<get-serializersModule>(){}[0]
+    final val shortValueClassHeaderName // kotlinx.serialization.csv.config/CsvConfig.shortValueClassHeaderName|{}shortValueClassHeaderName[0]
+        final fun <get-shortValueClassHeaderName>(): kotlin/Boolean // kotlinx.serialization.csv.config/CsvConfig.shortValueClassHeaderName.<get-shortValueClassHeaderName>|<get-shortValueClassHeaderName>(){}[0]
 
     final fun component1(): kotlin/Char // kotlinx.serialization.csv.config/CsvConfig.component1|component1(){}[0]
     final fun component10(): kotlin/Boolean // kotlinx.serialization.csv.config/CsvConfig.component10|component10(){}[0]
     final fun component11(): kotlin/Boolean // kotlinx.serialization.csv.config/CsvConfig.component11|component11(){}[0]
-    final fun component12(): kotlinx.serialization.modules/SerializersModule // kotlinx.serialization.csv.config/CsvConfig.component12|component12(){}[0]
+    final fun component12(): kotlin/Boolean // kotlinx.serialization.csv.config/CsvConfig.component12|component12(){}[0]
+    final fun component13(): kotlinx.serialization.modules/SerializersModule // kotlinx.serialization.csv.config/CsvConfig.component13|component13(){}[0]
     final fun component2(): kotlin/String // kotlinx.serialization.csv.config/CsvConfig.component2|component2(){}[0]
     final fun component3(): kotlin/Char // kotlinx.serialization.csv.config/CsvConfig.component3|component3(){}[0]
     final fun component4(): kotlinx.serialization.csv.config/QuoteMode // kotlinx.serialization.csv.config/CsvConfig.component4|component4(){}[0]
@@ -124,7 +130,7 @@ final class kotlinx.serialization.csv.config/CsvConfig { // kotlinx.serializatio
     final fun component7(): kotlin/Boolean // kotlinx.serialization.csv.config/CsvConfig.component7|component7(){}[0]
     final fun component8(): kotlin/Boolean // kotlinx.serialization.csv.config/CsvConfig.component8|component8(){}[0]
     final fun component9(): kotlin/Char // kotlinx.serialization.csv.config/CsvConfig.component9|component9(){}[0]
-    final fun copy(kotlin/Char = ..., kotlin/String = ..., kotlin/Char = ..., kotlinx.serialization.csv.config/QuoteMode = ..., kotlin/Char? = ..., kotlin/String = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin/Char = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlinx.serialization.modules/SerializersModule = ...): kotlinx.serialization.csv.config/CsvConfig // kotlinx.serialization.csv.config/CsvConfig.copy|copy(kotlin.Char;kotlin.String;kotlin.Char;kotlinx.serialization.csv.config.QuoteMode;kotlin.Char?;kotlin.String;kotlin.Boolean;kotlin.Boolean;kotlin.Char;kotlin.Boolean;kotlin.Boolean;kotlinx.serialization.modules.SerializersModule){}[0]
+    final fun copy(kotlin/Char = ..., kotlin/String = ..., kotlin/Char = ..., kotlinx.serialization.csv.config/QuoteMode = ..., kotlin/Char? = ..., kotlin/String = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin/Char = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlinx.serialization.modules/SerializersModule = ...): kotlinx.serialization.csv.config/CsvConfig // kotlinx.serialization.csv.config/CsvConfig.copy|copy(kotlin.Char;kotlin.String;kotlin.Char;kotlinx.serialization.csv.config.QuoteMode;kotlin.Char?;kotlin.String;kotlin.Boolean;kotlin.Boolean;kotlin.Char;kotlin.Boolean;kotlin.Boolean;kotlin.Boolean;kotlinx.serialization.modules.SerializersModule){}[0]
     final fun equals(kotlin/Any?): kotlin/Boolean // kotlinx.serialization.csv.config/CsvConfig.equals|equals(kotlin.Any?){}[0]
     final fun hashCode(): kotlin/Int // kotlinx.serialization.csv.config/CsvConfig.hashCode|hashCode(){}[0]
     final fun toString(): kotlin/String // kotlinx.serialization.csv.config/CsvConfig.toString|toString(){}[0]

library/api/library.klib.api

@@ -62,6 +62,11 @@ public class CsvBuilder internal constructor(
      */
     public var hasTrailingDelimiter: Boolean = config.hasTrailingDelimiter
 
+    /**
+     * Use short value class header name (default: `false`).
+     */
+    public var shortValueClassHeaderName: Boolean = config.shortValueClassHeaderName
+
     /**
      * Module with contextual and polymorphic serializers to be used in the resulting [Csv] instance.
      */
@@ -111,6 +116,7 @@ public class CsvBuilder internal constructor(
             headerSeparator = headerSeparator,
             ignoreUnknownColumns = ignoreUnknownColumns,
             hasTrailingDelimiter = hasTrailingDelimiter,
+            shortValueClassHeaderName = shortValueClassHeaderName,
             serializersModule = serializersModule,
         )
     }

library/src/commonMain/kotlin/kotlinx/serialization/csv/config/CsvBuilder.kt

@@ -17,6 +17,7 @@ import kotlinx.serialization.modules.SerializersModule
  * @param headerSeparator Character that is used to separate hierarchical header names (default: `.`).
  * @param ignoreUnknownColumns Ignore unknown columns when `hasHeaderRecord` is enabled (default: `false`).
  * @param hasTrailingDelimiter If records end with a trailing [delimiter] (default: `false`).
+ * @param shortValueClassHeaderName Use short value class header name (default: `false`).
  */
 public data class CsvConfig(
     val delimiter: Char = ',',
@@ -30,6 +31,7 @@ public data class CsvConfig(
     val headerSeparator: Char = '.',
     val ignoreUnknownColumns: Boolean = false,
     val hasTrailingDelimiter: Boolean = false,
+    val shortValueClassHeaderName: Boolean = false,
     val serializersModule: SerializersModule = EmptySerializersModule(),
 ) {
 

library/src/commonMain/kotlin/kotlinx/serialization/csv/config/CsvConfig.kt

@@ -102,6 +102,20 @@ internal abstract class CsvDecoder(
         }
     }
 
+    protected fun readPrimitiveHeaders(name: String) {
+        if (config.hasHeaderRecord && headers == null) {
+            val header = reader.readColumn()
+            if (header != name && header != "Null") {
+                error("Invalid header '$header' expected '$name.")
+            }
+            this.headers = Headers().apply {
+                set(0, 0)
+            }
+
+            readTrailingDelimiter()
+        }
+    }
+
     private fun readHeaders(descriptor: SerialDescriptor, prefix: String): Headers {
         val headers = Headers()
         var position = 0

library/src/commonMain/kotlin/kotlinx/serialization/csv/decode/CsvDecoder.kt

@@ -6,6 +6,7 @@ import kotlinx.serialization.descriptors.SerialDescriptor
 import kotlinx.serialization.descriptors.StructureKind
 import kotlinx.serialization.encoding.CompositeDecoder
 import kotlinx.serialization.encoding.CompositeDecoder.Companion.DECODE_DONE
+import kotlinx.serialization.encoding.Decoder
 
 /**
  * Initial entry point for decoding.
@@ -43,6 +44,66 @@ internal class RootCsvDecoder(
         readTrailingDelimiter()
     }
 
+    override fun decodeByte(): Byte {
+        readPrimitiveHeaders("Byte")
+        return super.decodeByte()
+    }
+
+    override fun decodeShort(): Short {
+        readPrimitiveHeaders("Short")
+        return super.decodeShort()
+    }
+
+    override fun decodeInt(): Int {
+        readPrimitiveHeaders("Int")
+        return decodeColumn().toInt()
+    }
+
+    override fun decodeLong(): Long {
+        readPrimitiveHeaders("Long")
+        return super.decodeLong()
+    }
+
+    override fun decodeFloat(): Float {
+        readPrimitiveHeaders("Float")
+        return super.decodeFloat()
+    }
+
+    override fun decodeDouble(): Double {
+        readPrimitiveHeaders("Double")
+        return super.decodeDouble()
+    }
+
+    override fun decodeBoolean(): Boolean {
+        readPrimitiveHeaders("Boolean")
+        return super.decodeBoolean()
+    }
+
+    override fun decodeChar(): Char {
+        readPrimitiveHeaders("Char")
+        return super.decodeChar()
+    }
+
+    override fun decodeString(): String {
+        readPrimitiveHeaders("String")
+        return super.decodeString()
+    }
+
+    override fun decodeNull(): Nothing? {
+        readPrimitiveHeaders("Null")
+        return super.decodeNull()
+    }
+
+    override fun decodeEnum(enumDescriptor: SerialDescriptor): Int {
+        readPrimitiveHeaders(enumDescriptor.serialName)
+        return super.decodeEnum(enumDescriptor)
+    }
+
+    override fun decodeInline(descriptor: SerialDescriptor): Decoder {
+        readHeaders(descriptor)
+        return super.decodeInline(descriptor)
+    }
+
     override fun decodeColumn(): String {
         val value = super.decodeColumn()
         position++

library/src/commonMain/kotlin/kotlinx/serialization/csv/decode/RootCsvDecoder.kt

@@ -45,8 +45,8 @@ internal abstract class CsvEncoder(
         StructureKind.CLASS,
         -> SimpleCsvEncoder(csv, writer, this)
 
-        StructureKind.OBJECT ->
-            ObjectCsvEncoder(csv, writer, this)
+        StructureKind.OBJECT,
+        -> ObjectCsvEncoder(csv, writer, this)
 
         PolymorphicKind.SEALED,
         -> SealedCsvEncoder(csv, writer, this, descriptor)
@@ -109,9 +109,19 @@ internal abstract class CsvEncoder(
     }
 
     protected fun printHeaderRecord(descriptor: SerialDescriptor) {
-        writer.beginRecord()
-        printHeader("", descriptor)
-        writer.endRecord()
+        if (config.hasHeaderRecord && writer.isFirstRecord) {
+            writer.beginRecord()
+            printHeader("", descriptor)
+            writer.endRecord()
+        }
+    }
+
+    protected fun printPrimitiveHeaderRecord(name: String) {
+        if (config.hasHeaderRecord && writer.isFirstRecord) {
+            writer.beginRecord()
+            writer.printColumn(name)
+            writer.endRecord()
+        }
     }
 
     private fun printHeader(prefix: String, descriptor: SerialDescriptor) {
@@ -137,6 +147,9 @@ internal abstract class CsvEncoder(
                 childDesc.kind is SerialKind.ENUM ->
                     writer.printColumn(name)
 
+                childDesc.isInline && config.shortValueClassHeaderName ->
+                    writer.printColumn(name)
+
                 childDesc.kind is PolymorphicKind.SEALED -> {
                     writer.printColumn(name)
                     val headerSeparator = config.headerSeparator

library/src/commonMain/kotlin/kotlinx/serialization/csv/encode/CsvEncoder.kt

@@ -18,9 +18,7 @@ internal class RecordListCsvEncoder(
         descriptor: SerialDescriptor,
     ): CompositeEncoder {
         // For complex records: Begin a new record and end it in [endChildStructure]
-        if (config.hasHeaderRecord && writer.isFirstRecord) {
-            printHeaderRecord(descriptor)
-        }
+        printHeaderRecord(descriptor)
         writer.beginRecord()
         return super.beginStructure(descriptor)
     }