add serialization support to ulid class

Author: daphil19

kulid/src/commonMain/kotlin/dev/phillipslabs/kulid/ULID.kt

@@ -4,6 +4,7 @@ import kotlinx.datetime.Clock
 import kotlinx.io.Buffer
 import kotlinx.io.bytestring.ByteString
 import kotlinx.io.readByteString
+import kotlinx.serialization.Serializable
 import org.kotlincrypto.random.CryptoRand
 import kotlin.jvm.JvmInline
 import kotlin.math.absoluteValue
@@ -28,7 +29,7 @@ private const val ULID_ENCODING_FRONT_PADDING = ENCODED_ULID_BYTE_SIZE * 5 - ULI
 // Crockford's base32 alphabet
 private val ENCODING_CHARS = "0123456789ABCDEFGHJKMNPQRSTVWXYZ".toCharArray()
 
-// @Serializable
+@Serializable(with = ULIDSerializer::class)
 @JvmInline
 public value class ULID private constructor(
     public val value: ByteString,

kulid/src/commonMain/kotlin/dev/phillipslabs/kulid/ULIDSerializer.kt

@@ -0,0 +1,23 @@
+package dev.phillipslabs.kulid
+
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+
+@OptIn(ExperimentalSerializationApi::class)
+public object ULIDSerializer : KSerializer<ULID> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("ULID", PrimitiveKind.STRING)
+
+    override fun serialize(
+        encoder: Encoder,
+        value: ULID,
+    ) {
+        encoder.encodeString(value.toString())
+    }
+
+    override fun deserialize(decoder: Decoder): ULID = ULID.fromString(decoder.decodeString())
+}