Add KotlinPropertyNameAsImplicitName option

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

@@ -1,7 +1,6 @@
 package com.fasterxml.jackson.module.kotlin
 
 import java.util.BitSet
-import kotlin.math.pow
 
 /**
  * @see KotlinModule.Builder
@@ -42,7 +41,24 @@ enum class KotlinFeature(private val enabledByDefault: Boolean) {
      * may contain null values after deserialization.
      * Enabling it protects against this but has significant performance impact.
      */
-    StrictNullChecks(enabledByDefault = false);
+    StrictNullChecks(enabledByDefault = false),
+
+    /**
+     * By enabling this feature, the property name on Kotlin is used as the implicit name for the getter.
+     *
+     * By default, the getter name is used during serialization.
+     * This name may be different from the parameter/field name, in which case serialization results
+     * may be incorrect or annotations may malfunction.
+     * See [jackson-module-kotlin#630] for details.
+     *
+     * By enabling this feature, such malfunctions will not occur.
+     *
+     * On the other hand, enabling this option increases the amount of reflection processing,
+     * which may result in performance degradation for both serialization and deserialization.
+     * In addition, the adjustment of behavior using get:JvmName is disabled.
+     * Note also that this feature does not apply to setters.
+     */
+    KotlinPropertyNameAsImplicitName(enabledByDefault = false);
 
     internal val bitSet: BitSet = (1 shl ordinal).toBitSet()
 

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

@@ -7,6 +7,7 @@ import com.fasterxml.jackson.module.kotlin.KotlinFeature.NullIsSameAsDefault
 import com.fasterxml.jackson.module.kotlin.KotlinFeature.NullToEmptyCollection
 import com.fasterxml.jackson.module.kotlin.KotlinFeature.NullToEmptyMap
 import com.fasterxml.jackson.module.kotlin.KotlinFeature.StrictNullChecks
+import com.fasterxml.jackson.module.kotlin.KotlinFeature.KotlinPropertyNameAsImplicitName
 import com.fasterxml.jackson.module.kotlin.SingletonSupport.CANONICALIZE
 import com.fasterxml.jackson.module.kotlin.SingletonSupport.DISABLED
 import java.util.*
@@ -53,7 +54,8 @@ class KotlinModule @Deprecated(
     val nullToEmptyMap: Boolean = false,
     val nullIsSameAsDefault: Boolean = false,
     val singletonSupport: SingletonSupport = DISABLED,
-    val strictNullChecks: Boolean = false
+    val strictNullChecks: Boolean = false,
+    val useKotlinPropertyNameForGetter: Boolean = false
 ) : SimpleModule(KotlinModule::class.java.name, PackageVersion.VERSION) {
     init {
         if (!KotlinVersion.CURRENT.isAtLeast(1, 5)) {
@@ -102,7 +104,8 @@ class KotlinModule @Deprecated(
             builder.isEnabled(KotlinFeature.SingletonSupport) -> CANONICALIZE
             else -> DISABLED
         },
-        builder.isEnabled(StrictNullChecks)
+        builder.isEnabled(StrictNullChecks),
+        builder.isEnabled(KotlinPropertyNameAsImplicitName)
     )
 
     companion object {
@@ -130,7 +133,13 @@ class KotlinModule @Deprecated(
         }
 
         context.insertAnnotationIntrospector(KotlinAnnotationIntrospector(context, cache, nullToEmptyCollection, nullToEmptyMap, nullIsSameAsDefault))
-        context.appendAnnotationIntrospector(KotlinNamesAnnotationIntrospector(this, cache, ignoredClassesForImplyingJsonCreator))
+        context.appendAnnotationIntrospector(
+            KotlinNamesAnnotationIntrospector(
+                this,
+                cache,
+                ignoredClassesForImplyingJsonCreator,
+                useKotlinPropertyNameForGetter)
+        )
 
         context.addDeserializers(KotlinDeserializers())
         context.addKeyDeserializers(KotlinKeyDeserializers)

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

@@ -24,35 +24,57 @@ import kotlin.reflect.full.hasAnnotation
 import kotlin.reflect.full.memberProperties
 import kotlin.reflect.full.primaryConstructor
 import kotlin.reflect.jvm.internal.KotlinReflectionInternalError
+import kotlin.reflect.jvm.javaGetter
 import kotlin.reflect.jvm.javaType
 import kotlin.reflect.jvm.kotlinFunction
 
-internal class KotlinNamesAnnotationIntrospector(val module: KotlinModule, val cache: ReflectionCache, val ignoredClassesForImplyingJsonCreator: Set<KClass<*>>) : NopAnnotationIntrospector() {
+internal class KotlinNamesAnnotationIntrospector(
+    val module: KotlinModule,
+    val cache: ReflectionCache,
+    val ignoredClassesForImplyingJsonCreator: Set<KClass<*>>,
+    val useKotlinPropertyNameForGetter: Boolean
+) : NopAnnotationIntrospector() {
+    private fun getterNameFromJava(member: AnnotatedMethod): String? {
+        val name = member.name
+
+        // The reason for truncating after `-` is to truncate the random suffix
+        // given after the value class accessor name.
+        return when {
+            name.startsWith("get") -> name.takeIf { it.contains("-") }?.let { _ ->
+                name.substringAfter("get")
+                    .replaceFirstChar { it.lowercase(Locale.getDefault()) }
+                    .substringBefore('-')
+            }
+            // since 2.15: support Kotlin's way of handling "isXxx" backed properties where
+            // logical property name needs to remain "isXxx" and not become "xxx" as with Java Beans
+            // (see https://kotlinlang.org/docs/reference/java-to-kotlin-interop.html and
+            //  https://github.com/FasterXML/jackson-databind/issues/2527 and
+            //  https://github.com/FasterXML/jackson-module-kotlin/issues/340
+            //  for details)
+            name.startsWith("is") -> if (name.contains("-")) name.substringAfter("-") else name
+            else -> null
+        }
+    }
+
+    private fun getterNameFromKotlin(member: AnnotatedMethod): String? {
+        val getter = member.member
+
+        return member.member.declaringClass.takeIf { it.isKotlinClass() }?.let { clazz ->
+            clazz.kotlin.memberProperties.find { it.javaGetter == getter }
+                ?.let { it.name }
+        }
+    }
+
     // since 2.4
     override fun findImplicitPropertyName(member: AnnotatedMember): String? {
         if (!member.declaringClass.isKotlinClass()) return null
 
-        val name = member.name
-
         return when (member) {
             is AnnotatedMethod -> if (member.parameterCount == 0) {
-                // The reason for truncating after `-` is to truncate the random suffix
-                // given after the value class accessor name.
-                when {
-                    name.startsWith("get") -> name.takeIf { it.contains("-") }?.let { _ ->
-                        name.substringAfter("get")
-                            .replaceFirstChar { it.lowercase(Locale.getDefault()) }
-                            .substringBefore('-')
-                    }
-                    // since 2.15: support Kotlin's way of handling "isXxx" backed properties where
-                    // logical property name needs to remain "isXxx" and not become "xxx" as with Java Beans
-                    // (see https://kotlinlang.org/docs/reference/java-to-kotlin-interop.html and
-                    //  https://github.com/FasterXML/jackson-databind/issues/2527 and
-                    //  https://github.com/FasterXML/jackson-module-kotlin/issues/340
-                    //  for details)
-                    name.startsWith("is") -> if (name.contains("-")) name.substringAfter("-") else name
-                    else -> null
-                }
+                if (useKotlinPropertyNameForGetter) {
+                    // Fall back to default if it is a getter-like function
+                    getterNameFromKotlin(member) ?: getterNameFromJava(member)
+                } else getterNameFromJava(member)
             } else null
             is AnnotatedParameter -> findKotlinParameterName(member)
             else -> null

src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/github/Github630.kt

@@ -0,0 +1,40 @@
+package com.fasterxml.jackson.module.kotlin.test.github
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.kotlin.KotlinFeature
+import com.fasterxml.jackson.module.kotlin.KotlinModule
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class Github630 {
+    private val mapper = ObjectMapper()
+        .registerModule(KotlinModule.Builder().enable(KotlinFeature.KotlinPropertyNameAsImplicitName).build())!!
+
+    data class Dto(
+        // from #570, #603
+        val FOO: Int = 0,
+        val bAr: Int = 0,
+        @JsonProperty("b")
+        val BAZ: Int = 0,
+        @JsonProperty("q")
+        val qUx: Int = 0,
+        // from #71
+        internal val quux: Int = 0,
+        // from #434
+        val `corge-corge`: Int = 0,
+        // additional
+        @get:JvmName("aaa")
+        val grault: Int = 0
+    )
+
+    @Test
+    fun test() {
+        val dto = Dto()
+
+        assertEquals(
+            """{"FOO":0,"bAr":0,"b":0,"q":0,"quux":0,"corge-corge":0,"grault":0}""",
+            mapper.writeValueAsString(dto)
+        )
+    }
+}