[#380] fix: add MetaDataSerializer

(cherry picked from commit e5148c4)

Author: MateuszNaKodach

kotlin/src/main/kotlin/org/axonframework/extensions/kotlin/serialization/MetaDataSerializer.kt

@@ -4,13 +4,11 @@ import kotlinx.serialization.KSerializer
 import kotlinx.serialization.builtins.MapSerializer
 import kotlinx.serialization.builtins.serializer
 import kotlinx.serialization.descriptors.SerialDescriptor
-import kotlinx.serialization.descriptors.buildClassSerialDescriptor
 import kotlinx.serialization.encoding.Decoder
 import kotlinx.serialization.encoding.Encoder
 import kotlinx.serialization.json.*
 import org.axonframework.messaging.MetaData
 
-
 object MetaDataSerializer : KSerializer<MetaData> {
 
     private val json = Json { encodeDefaults = true; ignoreUnknownKeys = true }
@@ -41,7 +39,8 @@ object MetaDataSerializer : KSerializer<MetaData> {
         is Float -> JsonPrimitive(value)
         is Double -> JsonPrimitive(value)
         is Map<*, *> -> JsonObject(value.entries.associate { (k, v) -> k.toString() to toJsonElement(v) })
-        is List<*> -> JsonArray(value.map { toJsonElement(it) })
+        is Collection<*> -> JsonArray(value.map { toJsonElement(it) })
+        is Array<*> -> JsonArray(value.map { toJsonElement(it) })
         else -> JsonPrimitive(value.toString())
     }
 
@@ -59,20 +58,4 @@ object MetaDataSerializer : KSerializer<MetaData> {
         is JsonObject -> element.mapValues { fromJsonElement(it.value) }
         is JsonArray -> element.map { fromJsonElement(it) }
     }
-}
-
-object JsonElementSerializer : KSerializer<JsonElement> {
-    private val json = Json { encodeDefaults = true }
-
-    override val descriptor: SerialDescriptor = buildClassSerialDescriptor("kotlinx.serialization.json.JsonElement")
-
-    override fun serialize(encoder: Encoder, value: JsonElement) {
-        val jsonString = json.encodeToString(JsonElement.serializer(), value)
-        encoder.encodeString(jsonString)
-    }
-
-    override fun deserialize(decoder: Decoder): JsonElement {
-        val jsonString = decoder.decodeString()
-        return json.decodeFromString(JsonElement.serializer(), jsonString)
-    }
 }

kotlin/src/test/kotlin/org/axonframework/extensions/kotlin/serializer/MetaDataSerializerTest.kt

@@ -167,17 +167,8 @@ class MetaDataSerializerTest {
         val serialized = jsonSerializer.serialize(metaData, String::class.java)
         val deserialized = jsonSerializer.deserialize<String, MetaData>(serialized)
 
-        assertEquals(metaData.size, deserialized!!.size)
-
-        // The nested map will be serialized as a string
-        val deserializedValue = deserialized["mapValue"]
-        assertTrue(deserializedValue is String)
-
-        // Verify the string representation contains the map content
-        val valueAsString = deserializedValue.toString()
-        assertTrue(valueAsString.contains("key1"))
-        assertTrue(valueAsString.contains("value1"))
-        assertTrue(valueAsString.contains("nested"))
+        val deserializedValue = deserialized!!["mapValue"]
+        assertEquals(nestedMap, deserializedValue)
     }
 
     @Test
@@ -191,39 +182,10 @@ class MetaDataSerializerTest {
 
         assertEquals(metaData.size, deserialized!!.size)
 
-        // The list will be serialized as a string
-        val deserializedValue = deserialized["listValue"]
-        assertTrue(deserializedValue is String)
-
-        // Verify the string representation contains the list items
-        val valueAsString = deserializedValue.toString()
-        assertTrue(valueAsString.contains("item1"))
-        assertTrue(valueAsString.contains("item2"))
-        assertTrue(valueAsString.contains("item3"))
-    }
-
-    @Test
-    fun `should handle custom objects in MetaData`() {
-        // Define a custom object class for testing
-        data class Person(val name: String, val age: Int)
-
-        val person = Person("John Doe", 30)
-
-        val metaData = MetaData.with("personValue", person)
-
-        val serialized = jsonSerializer.serialize(metaData, String::class.java)
-        val deserialized = jsonSerializer.deserialize<String, MetaData>(serialized)
-
-        assertEquals(metaData.size, deserialized!!.size)
-
-        // The custom object will be serialized as a string
-        val deserializedValue = deserialized["personValue"]
-        assertTrue(deserializedValue is String)
-
-        // Verify the string representation contains the object properties
-        val valueAsString = deserializedValue.toString()
-        assertTrue(valueAsString.contains("John Doe"))
-        assertTrue(valueAsString.contains("30"))
+        val deserializedValue = deserialized["listValue"] as List<*>
+        assertTrue(deserializedValue.contains("item1"))
+        assertTrue(deserializedValue.contains("item2"))
+        assertTrue(deserializedValue.contains("item3"))
     }
 
     @Test
@@ -248,57 +210,32 @@ class MetaDataSerializerTest {
 
         assertEquals(metaData.size, deserialized!!.size)
 
-        // The complex structure will be serialized as a string
-        val deserializedValue = deserialized["complexValue"]
-        assertTrue(deserializedValue is String)
-
-        // Verify the string representation contains key elements
-        val valueAsString = deserializedValue.toString()
-        assertTrue(valueAsString.contains("string"))
-        assertTrue(valueAsString.contains("value"))
-        assertTrue(valueAsString.contains("42"))
-        assertTrue(valueAsString.contains("nestedMap"))
-        assertTrue(valueAsString.contains("deepValue"))
+        val deserializedValue = deserialized["complexValue"] as Map<*, *>
+        assertEquals(deserializedValue, complexStructure)
     }
 
     @Test
-    fun `should handle arrays in MetaData`() {
-        val array = arrayOf("first", "second", "third")
+    fun `should handle custom objects in MetaData`() {
+        // Define a custom object class for testing
+        data class Person(val name: String, val age: Int)
 
-        val metaData = MetaData.with("arrayValue", array)
+        val person = Person("John Doe", 30)
+
+        val metaData = MetaData.with("personValue", person)
 
         val serialized = jsonSerializer.serialize(metaData, String::class.java)
         val deserialized = jsonSerializer.deserialize<String, MetaData>(serialized)
 
         assertEquals(metaData.size, deserialized!!.size)
 
-        // The array will be serialized as a string
-        val deserializedValue = deserialized["arrayValue"]
+        // The custom object will be serialized as a string
+        val deserializedValue = deserialized["personValue"]
         assertTrue(deserializedValue is String)
 
-        // Verify the string representation contains the array items
+        // Verify the string representation contains the object properties
         val valueAsString = deserializedValue.toString()
-        assertTrue(valueAsString.contains("first"))
-        assertTrue(valueAsString.contains("second"))
-        assertTrue(valueAsString.contains("third"))
+        assertTrue(valueAsString.contains("John Doe"))
+        assertTrue(valueAsString.contains("30"))
     }
 
-    @Test
-    fun `should handle Date objects in MetaData`() {
-        val date = Date()
-
-        val metaData = MetaData.with("dateValue", date)
-
-        val serialized = jsonSerializer.serialize(metaData, String::class.java)
-        val deserialized = jsonSerializer.deserialize<String, MetaData>(serialized)
-
-        assertEquals(metaData.size, deserialized!!.size)
-
-        // The date will be serialized as a string
-        val deserializedValue = deserialized["dateValue"]
-        assertTrue(deserializedValue is String)
-
-        // Verify the string representation is the date's toString() value
-        assertEquals(date.toString(), deserializedValue)
-    }
 }