merging PR #261 for serdes Kotlin Sequences

Author: apatrida

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinBeanDeserializerModifier.kt

@@ -6,14 +6,15 @@ import com.fasterxml.jackson.databind.JsonDeserializer
 import com.fasterxml.jackson.databind.deser.BeanDeserializerModifier
 
 // [module-kotlin#225]: keep Kotlin singletons as singletons
-object KotlinBeanDeserializerModifier: BeanDeserializerModifier() {
+object KotlinBeanDeserializerModifier : BeanDeserializerModifier() {
     override fun modifyDeserializer(
             config: DeserializationConfig,
             beanDesc: BeanDescription,
             deserializer: JsonDeserializer<*>
     ): JsonDeserializer<out Any> {
         val modifiedFromParent = super.modifyDeserializer(config, beanDesc, deserializer)
-	val objectSingletonInstance = objectSingletonInstance(beanDesc.beanClass)
+
+        val objectSingletonInstance = objectSingletonInstance(beanDesc.beanClass)
         return if (objectSingletonInstance != null) {
             KotlinObjectSingletonDeserializer(objectSingletonInstance, modifiedFromParent)
         } else {

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinDeserializers.kt

@@ -0,0 +1,22 @@
+package com.fasterxml.jackson.module.kotlin
+
+import com.fasterxml.jackson.core.JsonParser
+import com.fasterxml.jackson.databind.*
+import com.fasterxml.jackson.databind.deser.Deserializers
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer
+
+object SequenceDeserializer : StdDeserializer<Sequence<*>>(Sequence::class.java) {
+    override fun deserialize(p: JsonParser, ctxt: DeserializationContext): Sequence<*> {
+        return ctxt.readValue(p, List::class.java).asSequence()
+    }
+}
+
+internal class KotlinDeserializers: Deserializers.Base() {
+    override fun findBeanDeserializer(type: JavaType, config: DeserializationConfig?, beanDesc: BeanDescription?): JsonDeserializer<*>? {
+        return if (type.isInterface && type.rawClass == Sequence::class.java) {
+            SequenceDeserializer
+        } else {
+            null
+        }
+    }
+}

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinModule.kt

@@ -3,20 +3,18 @@ package com.fasterxml.jackson.module.kotlin
 import com.fasterxml.jackson.annotation.JsonCreator
 import com.fasterxml.jackson.annotation.JsonProperty
 import com.fasterxml.jackson.databind.MapperFeature
-import com.fasterxml.jackson.databind.introspect.Annotated
-import com.fasterxml.jackson.databind.introspect.AnnotatedConstructor
-import com.fasterxml.jackson.databind.introspect.AnnotatedMember
-import com.fasterxml.jackson.databind.introspect.AnnotatedParameter
-import com.fasterxml.jackson.databind.introspect.NopAnnotationIntrospector
+import com.fasterxml.jackson.databind.introspect.*
 import com.fasterxml.jackson.databind.module.SimpleModule
 import com.fasterxml.jackson.databind.util.LRUMap
 import java.lang.reflect.Constructor
 import java.lang.reflect.Method
-import java.lang.reflect.Modifier
 import kotlin.reflect.KClass
 import kotlin.reflect.KFunction
 import kotlin.reflect.KParameter
-import kotlin.reflect.full.*
+import kotlin.reflect.full.companionObject
+import kotlin.reflect.full.declaredFunctions
+import kotlin.reflect.full.memberProperties
+import kotlin.reflect.full.primaryConstructor
 import kotlin.reflect.jvm.internal.KotlinReflectionInternalError
 import kotlin.reflect.jvm.javaType
 import kotlin.reflect.jvm.kotlinFunction
@@ -46,13 +44,16 @@ class KotlinModule(val reflectionCacheSize: Int = 512, val nullToEmptyCollection
         // [module-kotlin#225]: keep Kotlin singletons as singletons
         context.addBeanDeserializerModifier(KotlinBeanDeserializerModifier)
 
+        context.insertAnnotationIntrospector(KotlinAnnotationIntrospector(context, cache, nullToEmptyCollection, nullToEmptyMap))
+        context.appendAnnotationIntrospector(KotlinNamesAnnotationIntrospector(this, cache))
+
+        context.addDeserializers(KotlinDeserializers())
+        context.addSerializers(KotlinSerializers())
+
         fun addMixIn(clazz: Class<*>, mixin: Class<*>) {
             context.setMixInAnnotations(clazz, mixin)
         }
 
-        context.insertAnnotationIntrospector(KotlinAnnotationIntrospector(context, cache, nullToEmptyCollection, nullToEmptyMap))
-        context.appendAnnotationIntrospector(KotlinNamesAnnotationIntrospector(this, cache))
-
         // ranges
         addMixIn(IntRange::class.java, ClosedRangeMixin::class.java)
         addMixIn(CharRange::class.java, ClosedRangeMixin::class.java)

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinSerializers.kt

@@ -0,0 +1,23 @@
+package com.fasterxml.jackson.module.kotlin
+
+import com.fasterxml.jackson.core.JsonGenerator
+import com.fasterxml.jackson.databind.*
+import com.fasterxml.jackson.databind.ser.Serializers
+import com.fasterxml.jackson.databind.ser.std.StdSerializer
+
+object SequenceSerializer : StdSerializer<Sequence<*>>(Sequence::class.java) {
+    override fun serialize(value: Sequence<*>, gen: JsonGenerator, provider: SerializerProvider) {
+        val materializedList = value.toList()
+        provider.defaultSerializeValue(materializedList, gen)
+    }
+}
+
+internal class KotlinSerializers : Serializers.Base() {
+    override fun findSerializer(config: SerializationConfig?, type: JavaType, beanDesc: BeanDescription?): JsonSerializer<*>? {
+        return if (Sequence::class.java.isAssignableFrom(type.rawClass)) {
+            SequenceSerializer
+        } else {
+            null
+        }
+    }
+}

src/main/kotlin/com/fasterxml/jackson/module/kotlin/deserializers/SequenceDeserializer.kt

@@ -0,0 +1,45 @@
+package com.fasterxml.jackson.module.kotlin.test
+
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
+import org.junit.Test
+import kotlin.test.assertEquals
+
+
+class SequenceDeserializerTest {
+    data class Data(val value: Sequence<String>)
+
+    @Test
+    fun deserializeSequence() {
+        val list = listOf("Test", "Test1")
+        val objectMapper = jacksonObjectMapper()
+        val result = objectMapper.readValue<Data>("{\"value\":[\"Test\",\"Test1\"]}")
+        assertEquals(list, result.value.toList())
+    }
+
+    @Test
+    fun deserializeEmptySequence() {
+        val list = listOf<String>()
+        val objectMapper = jacksonObjectMapper()
+        val result = objectMapper.readValue<Data>("{\"value\":[]}")
+        assertEquals(list, result.value.toList())
+    }
+
+    @Test
+    fun testSerializeSequence() {
+        val sequence = listOf("item1", "item2").asSequence()
+        val data = Data(sequence)
+        val objectMapper = jacksonObjectMapper()
+        val result = objectMapper.writeValueAsString(data)
+        assertEquals("{\"value\":[\"item1\",\"item2\"]}", result)
+    }
+
+    @Test
+    fun testSerializeEmptySequence() {
+        val sequence = listOf<String>().asSequence()
+        val data = Data(sequence)
+        val objectMapper =  jacksonObjectMapper()
+        val result = objectMapper.writeValueAsString(data)
+        assertEquals("{\"value\":[]}", result)
+    }
+}