Null in Optional type fields should not fail (#576)

Signed-off-by: David Kral <[email protected]>

src/main/java/org/eclipse/yasson/internal/serializer/OptionalSerializer.java

@@ -33,7 +33,7 @@ class OptionalSerializer implements ModelSerializer {
     @Override
     public void serialize(Object value, JsonGenerator generator, SerializationContextImpl context) {
         Optional<Object> optional = (Optional<Object>) value;
-        delegate.serialize(optional.orElse(null), generator, context);
+        delegate.serialize(optional == null ? null : optional.orElse(null), generator, context);
     }
 
 }

src/main/java/org/eclipse/yasson/internal/serializer/types/OptionalDoubleSerializer.java

@@ -33,7 +33,7 @@ class OptionalDoubleSerializer implements ModelSerializer {
     @Override
     public void serialize(Object value, JsonGenerator generator, SerializationContextImpl context) {
         OptionalDouble optionalDouble = (OptionalDouble) value;
-        if (optionalDouble.isPresent()) {
+        if (optionalDouble != null && optionalDouble.isPresent()) {
             typeSerializer.serialize(optionalDouble.getAsDouble(), generator, context);
         } else {
             typeSerializer.serialize(null, generator, context);

src/main/java/org/eclipse/yasson/internal/serializer/types/OptionalIntSerializer.java

@@ -33,7 +33,7 @@ class OptionalIntSerializer implements ModelSerializer {
     @Override
     public void serialize(Object value, JsonGenerator generator, SerializationContextImpl context) {
         OptionalInt optionalInt = (OptionalInt) value;
-        if (optionalInt.isPresent()) {
+        if (optionalInt != null && optionalInt.isPresent()) {
             typeSerializer.serialize(optionalInt.getAsInt(), generator, context);
         } else {
             typeSerializer.serialize(null, generator, context);

src/main/java/org/eclipse/yasson/internal/serializer/types/OptionalLongSerializer.java

@@ -33,7 +33,7 @@ class OptionalLongSerializer implements ModelSerializer {
     @Override
     public void serialize(Object value, JsonGenerator generator, SerializationContextImpl context) {
         OptionalLong optionalLong = (OptionalLong) value;
-        if (optionalLong.isPresent()) {
+        if (optionalLong != null && optionalLong.isPresent()) {
             typeSerializer.serialize(optionalLong.getAsLong(), generator, context);
         } else {
             typeSerializer.serialize(null, generator, context);

src/test/java/org/eclipse/yasson/defaultmapping/specific/OptionalTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022 Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2019, 2020 Payara Foundation and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
@@ -13,7 +13,11 @@
 
 package org.eclipse.yasson.defaultmapping.specific;
 
+import org.eclipse.yasson.defaultmapping.specific.model.SpecificOptionalWrapper;
 import org.junit.jupiter.api.*;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.jupiter.api.Assertions.*;
 import static org.eclipse.yasson.Jsonbs.*;
 
@@ -189,6 +193,20 @@ public void testUnmarshalEmptyDouble() {
         assertEquals(OptionalDouble.empty(), bindingJsonb.fromJson("null", OptionalDouble.class));
     }
 
+    @Test
+    public void testNullInsteadOfOptional() {
+        OptionalWrapper optionalWrapper = new OptionalWrapper();
+        String expected = "{}";
+        assertThat(bindingJsonb.toJson(optionalWrapper), is(expected));
+    }
+
+    @Test
+    public void testNullInsteadOfOptionalInSpecificOptionals() {
+        SpecificOptionalWrapper optionalWrapper = new SpecificOptionalWrapper();
+        String expected = "{}";
+        assertThat(bindingJsonb.toJson(optionalWrapper), is(expected));
+    }
+
     public static class Customer {
         private int id;
         private String name;

src/test/java/org/eclipse/yasson/defaultmapping/specific/model/SpecificOptionalWrapper.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.yasson.defaultmapping.specific.model;
+
+import java.util.OptionalDouble;
+import java.util.OptionalInt;
+import java.util.OptionalLong;
+
+public class SpecificOptionalWrapper {
+
+    private OptionalInt optionalInt;
+    private OptionalLong optionalLong;
+    private OptionalDouble optionalDouble;
+
+    public OptionalInt optionalInt() {
+        return optionalInt;
+    }
+
+    public void setOptionalInt(OptionalInt optionalInt) {
+        this.optionalInt = optionalInt;
+    }
+
+    public OptionalLong optionalLong() {
+        return optionalLong;
+    }
+
+    public void setOptionalLong(OptionalLong optionalLong) {
+        this.optionalLong = optionalLong;
+    }
+
+    public OptionalDouble optionalDouble() {
+        return optionalDouble;
+    }
+
+    public void setOptionalDouble(OptionalDouble optionalDouble) {
+        this.optionalDouble = optionalDouble;
+    }
+
+}