Support for value classes

resolve: FasterXML#199

Author: wplong11

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

@@ -127,11 +127,11 @@ internal class KotlinNamesAnnotationIntrospector(
             if (member is Constructor<*>) {
                 val ctor = (member as Constructor<Any>)
                 val ctorParmCount = ctor.parameterTypes.size
-                val ktorParmCount = try { ctor.kotlinFunction?.parameters?.size ?: 0 }
+                val ktorParmCount = try { ctor.kotlinCtor?.parameters?.size ?: 0 }
                 catch (ex: KotlinReflectionInternalError) { 0 }
                 catch (ex: UnsupportedOperationException) { 0 }
                 if (ktorParmCount > 0 && ktorParmCount == ctorParmCount) {
-                    ctor.kotlinFunction?.parameters?.get(param.index)?.name
+                    ctor.kotlinCtor?.parameters?.get(param.index)?.name
                 } else {
                     null
                 }

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

@@ -0,0 +1,16 @@
+package com.fasterxml.jackson.module.kotlin
+
+import java.lang.reflect.Constructor
+import kotlin.reflect.KFunction
+import kotlin.reflect.jvm.javaConstructor
+
+val <T : Any> Constructor<T>.kotlinCtor: KFunction<T>?
+    get() {
+        val kotlinClass = declaringClass.kotlin
+        return if (kotlinClass.isValue) {
+            val parameterTypes = this.parameters.map { p -> p.type }
+            kotlinClass.constructors.firstOrNull { it.parameters.map { p -> p.type.erasedType() } == parameterTypes }
+        } else {
+            kotlinClass.constructors.firstOrNull { it.javaConstructor == this }
+        }
+    }

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

@@ -58,7 +58,7 @@ internal class ReflectionCache(reflectionCacheSize: Int) : Serializable {
         LRUMap(0, reflectionCacheSize)
 
     fun kotlinFromJava(key: Constructor<Any>): KFunction<Any>? = javaConstructorToKotlin.get(key)
-            ?: key.kotlinFunction?.let { javaConstructorToKotlin.putIfAbsent(key, it) ?: it }
+            ?: key.kotlinCtor?.let { javaConstructorToKotlin.putIfAbsent(key, it) ?: it }
 
     fun kotlinFromJava(key: Method): KFunction<*>? = javaMethodToKotlin.get(key)
             ?: key.kotlinFunction?.let { javaMethodToKotlin.putIfAbsent(key, it) ?: it }

src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/ValueClassTest.kt

@@ -0,0 +1,21 @@
+package com.fasterxml.jackson.module.kotlin.test
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.kotlin.kotlinModule
+import org.junit.Assert
+import org.junit.Test
+
+class ValueClassTest {
+    @JvmInline
+    value class TestClass(val foo: List<Int>)
+
+    @Test
+    fun `test value class`() {
+        val mapper = createMapper()
+        Assert.assertEquals(listOf(1, 2), mapper.readValue("""{"foo": [1,2]}""", TestClass::class.java).foo)
+    }
+
+    private fun createMapper(): ObjectMapper {
+        return ObjectMapper().registerModule(kotlinModule())
+    }
+}