Add module configuration flag to treat null values as defaults instea…

…d of doing this without warning.
FasterXML · Oct 26, 2019 · 45676ce · 45676ce
1 parent 2552fd7
commit 45676ce
Show file tree

Hide file tree

Showing 4 changed files with 44 additions and 12 deletions.
diff --git a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinAnnotationIntrospector.kt b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinAnnotationIntrospector.kt
@@ -18,7 +18,14 @@ import kotlin.reflect.full.declaredMemberProperties
 import kotlin.reflect.jvm.*
 
 
-internal class KotlinAnnotationIntrospector(private val context: Module.SetupContext, private val cache: ReflectionCache, private val nullToEmptyCollection: Boolean, private val nullToEmptyMap: Boolean) : NopAnnotationIntrospector() {
+internal class KotlinAnnotationIntrospector(private val context: Module.SetupContext,
+                                            private val cache: ReflectionCache,
+                                            private val nullToEmptyCollection: Boolean,
+                                            private val nullToEmptyMap: Boolean,
+                                            private val nullIsSameAsDefault: Boolean) : NopAnnotationIntrospector() {
+
+    // TODO: implement nullIsSameAsDefault flag, which represents when TRUE that if something has a default value, it can be passed a null to default it
+    //       this likely impacts this class to be accurate about what COULD be considered required
 
     override fun hasRequiredMarker(m: AnnotatedMember): Boolean? =
         cache.javaMemberIsRequired(m) {

diff --git a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinModule.kt b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinModule.kt
@@ -27,7 +27,7 @@ fun Class<*>.isKotlinClass(): Boolean {
     return declaredAnnotations.any { it.annotationClass.java.name == metadataFqName }
 }
 
-class KotlinModule(val reflectionCacheSize: Int = 512, val nullToEmptyCollection: Boolean = false, val nullToEmptyMap: Boolean = false) : SimpleModule(PackageVersion.VERSION) {
+class KotlinModule(val reflectionCacheSize: Int = 512, val nullToEmptyCollection: Boolean = false, val nullToEmptyMap: Boolean = false, val nullisSameAsDefault: Boolean = false) : SimpleModule(PackageVersion.VERSION) {
     companion object {
         const val serialVersionUID = 1L
     }
@@ -41,12 +41,12 @@ class KotlinModule(val reflectionCacheSize: Int = 512, val nullToEmptyCollection
 
         val cache = ReflectionCache(reflectionCacheSize)
 
-        context.addValueInstantiators(KotlinInstantiators(cache, nullToEmptyCollection, nullToEmptyMap))
+        context.addValueInstantiators(KotlinInstantiators(cache, nullToEmptyCollection, nullToEmptyMap, nullisSameAsDefault))
 
         // [module-kotlin#225]: keep Kotlin singletons as singletons
         context.addBeanDeserializerModifier(KotlinBeanDeserializerModifier)
 
-        context.insertAnnotationIntrospector(KotlinAnnotationIntrospector(context, cache, nullToEmptyCollection, nullToEmptyMap))
+        context.insertAnnotationIntrospector(KotlinAnnotationIntrospector(context, cache, nullToEmptyCollection, nullToEmptyMap, nullisSameAsDefault))
         context.appendAnnotationIntrospector(KotlinNamesAnnotationIntrospector(this, cache))
 
         context.addDeserializers(KotlinDeserializers())

diff --git a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinValueInstantiator.kt b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinValueInstantiator.kt
@@ -24,7 +24,8 @@ internal class KotlinValueInstantiator(
     src: StdValueInstantiator,
     private val cache: ReflectionCache,
     private val nullToEmptyCollection: Boolean,
-    private val nullToEmptyMap: Boolean
+    private val nullToEmptyMap: Boolean,
+    private val nullIsSameAsDefault: Boolean
 ) : StdValueInstantiator(src) {
     @Suppress("UNCHECKED_CAST")
     override fun createFromObjectWith(
@@ -91,7 +92,7 @@ internal class KotlinValueInstantiator(
 
             var paramVal = if (!isMissing || paramDef.isPrimitive() || jsonProp.hasInjectableValueId()) {
                 val tempParamVal = buffer.getParameter(jsonProp)
-                if (tempParamVal == null && paramDef.isOptional) {
+                if (nullIsSameAsDefault && tempParamVal == null && paramDef.isOptional) {
                     return@forEachIndexed
                 }
                 tempParamVal
@@ -159,7 +160,8 @@ internal class KotlinValueInstantiator(
 internal class KotlinInstantiators(
     private val cache: ReflectionCache,
     private val nullToEmptyCollection: Boolean,
-    private val nullToEmptyMap: Boolean
+    private val nullToEmptyMap: Boolean,
+    private val nullIsSameAsDefault: Boolean
 ) : ValueInstantiators {
     override fun findValueInstantiator(
         deserConfig: DeserializationConfig,
@@ -168,7 +170,7 @@ internal class KotlinInstantiators(
     ): ValueInstantiator {
         return if (beanDescriptor.beanClass.isKotlinClass()) {
             if (defaultInstantiator is StdValueInstantiator) {
-                KotlinValueInstantiator(defaultInstantiator, cache, nullToEmptyCollection, nullToEmptyMap)
+                KotlinValueInstantiator(defaultInstantiator, cache, nullToEmptyCollection, nullToEmptyMap, nullIsSameAsDefault)
             } else {
                 // TODO: return defaultInstantiator and let default method parameters and nullability go unused?  or die with exception:
                 throw IllegalStateException("KotlinValueInstantiator requires that the default ValueInstantiator is StdValueInstantiator")

diff --git a/src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/NullToDefault.kt b/src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/NullToDefault.kt
@@ -1,5 +1,7 @@
 package com.fasterxml.jackson.module.kotlin.test
 
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.kotlin.KotlinModule
 import com.fasterxml.jackson.module.kotlin.MissingKotlinParameterException
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import com.fasterxml.jackson.module.kotlin.readValue
@@ -11,7 +13,7 @@ import org.junit.internal.runners.statements.ExpectException
 // @Ignore("not yet implemented, under discussion")
 class NullToDefault {
 
-	private fun createMapper() = jacksonObjectMapper()
+	private fun createMapper(allowDefaultingByNull: Boolean) = ObjectMapper().registerModule(KotlinModule(nullisSameAsDefault = allowDefaultingByNull))
 
 	private data class TestClass(val sku: Int = -1,
 								 val text: String,
@@ -22,8 +24,29 @@ class NullToDefault {
 								 val order: Int = -1)
 
 	@Test
-	fun shouldUseDefault() {
-		val item = createMapper().readValue<TestClass>(
+	fun shouldUseNullAsDefault() {
+		val item = createMapper(true).readValue<TestClass>(
+				"""{
+					"sku": "974",
+					"text": "plain",
+					"name": null,
+					"images": null,
+					"attribute": "19"     
+				}""")
+
+		Assert.assertTrue(item.sku == 974)
+		Assert.assertTrue(item.text == "plain")
+		@Suppress("SENSELESS_COMPARISON")
+		Assert.assertTrue(item.name != null)
+		Assert.assertTrue(item.images == null)
+		Assert.assertTrue(item.language == "uk")
+		Assert.assertTrue(item.attribute == 19)
+		Assert.assertTrue(item.order == -1)
+	}
+
+	@Test(expected = MissingKotlinParameterException::class)
+	fun shouldNotUseNullAsDefault() {
+		val item = createMapper(false).readValue<TestClass>(
 				"""{
 					"sku": "974",
 					"text": "plain",
@@ -44,7 +67,7 @@ class NullToDefault {
 
 	@Test(expected = MissingKotlinParameterException::class)
 	fun errorIfNotDefault() {
-		val item = createMapper().readValue<TestClass>(
+		val item = createMapper(true).readValue<TestClass>(
 				"""{
 						"sku": "974",
 						"text": null,