[Fix #380] oneOf as Optional

Author: fjtirado

api/pom.xml

@@ -29,6 +29,10 @@
             <groupId>com.fasterxml.jackson.dataformat</groupId>
             <artifactId>jackson-dataformat-yaml</artifactId>
         </dependency>
+        <dependency>
+           <groupId>com.fasterxml.jackson.datatype</groupId>
+           <artifactId>jackson-datatype-jdk8</artifactId>
+        </dependency>
         <dependency>
             <groupId>jakarta.validation</groupId>
             <artifactId>jakarta.validation-api</artifactId>

api/src/main/java/io/serverlessworkflow/api/ObjectMapperFactory.java

@@ -20,6 +20,7 @@
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator.Feature;
+import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
 import io.serverlessworkflow.api.types.CallTask;
 import io.serverlessworkflow.api.types.SwitchItem;
 import io.serverlessworkflow.api.types.Task;
@@ -55,7 +56,8 @@ private static ObjectMapper configure(ObjectMapper mapper) {
         .configure(SerializationFeature.INDENT_OUTPUT, true)
         .configure(SerializationFeature.WRITE_EMPTY_JSON_ARRAYS, false)
         .configure(SerializationFeature.WRITE_NULL_MAP_VALUES, false)
-        .registerModule(simpleModule);
+        .registerModule(simpleModule)
+        .registerModule(new Jdk8Module());
   }
 
   private ObjectMapperFactory() {}

api/src/main/java/io/serverlessworkflow/api/SerializeHelper.java

@@ -18,13 +18,14 @@
 import com.fasterxml.jackson.core.JsonGenerator;
 import java.io.IOException;
 import java.lang.reflect.Method;
+import java.util.Optional;
 
 public class SerializeHelper {
   public static void serializeOneOf(JsonGenerator jgen, Object item) throws IOException {
     try {
       for (Method m : item.getClass().getDeclaredMethods()) {
-        Object value = m.invoke(item);
-        if (value != null) {
+        Optional<?> value = (Optional<?>) m.invoke(item);
+        if (value.isPresent()) {
           jgen.writeObject(value);
           break;
         }

api/src/test/java/io/serverlessworkflow/api/ApiTest.java

@@ -23,6 +23,7 @@
 import io.serverlessworkflow.api.types.Task;
 import io.serverlessworkflow.api.types.Workflow;
 import java.io.IOException;
+import java.util.Optional;
 import org.junit.jupiter.api.Test;
 
 public class ApiTest {
@@ -34,12 +35,12 @@ void testCallHTTPAPI() throws IOException {
     assertThat(workflow.getDo().get(0).getName()).isNotNull();
     assertThat(workflow.getDo().get(0).getTask()).isNotNull();
     Task task = workflow.getDo().get(0).getTask();
-    CallTask callTask = task.getCallTask();
-    assertThat(callTask).isNotNull();
-    assertThat(task.getDoTask()).isNull();
-    CallHTTP httpCall = callTask.getCallHTTP();
-    assertThat(httpCall).isNotNull();
-    assertThat(callTask.getCallAsyncAPI()).isNull();
-    assertThat(httpCall.getWith().getMethod()).isEqualTo("get");
+    Optional<CallTask> callTask = task.getCallTask();
+    assertThat(callTask).isPresent();
+    assertThat(task.getDoTask()).isEmpty();
+    Optional<CallHTTP> httpCall = callTask.flatMap(CallTask::getCallHTTP);
+    assertThat(httpCall).isPresent();
+    assertThat(callTask.flatMap(CallTask::getCallAsyncAPI)).isEmpty();
+    assertThat(httpCall.get().getWith().getMethod()).isEqualTo("get");
   }
 }

custom-generator/src/main/java/io/serverlessworkflow/generator/AllAnyOneOfSchemaRule.java

@@ -125,7 +125,7 @@ private JDefinedClass createUnionClass(
 
   private void wrapIt(JDefinedClass definedClass, JType unionType) {
     JFieldVar instanceField =
-        GeneratorUtils.addGetter(
+        GeneratorUtils.addOptionalGetter(
             definedClass, unionType, ruleFactory.getNameHelper(), unionType.name());
     JMethod constructor = definedClass.constructor(JMod.PUBLIC);
     constructor

custom-generator/src/main/java/io/serverlessworkflow/generator/GeneratorUtils.java

@@ -15,11 +15,13 @@
  */
 package io.serverlessworkflow.generator;
 
+import com.sun.codemodel.JClass;
 import com.sun.codemodel.JDefinedClass;
 import com.sun.codemodel.JFieldVar;
 import com.sun.codemodel.JMethod;
 import com.sun.codemodel.JMod;
 import com.sun.codemodel.JType;
+import java.util.Optional;
 import org.jsonschema2pojo.util.NameHelper;
 
 public class GeneratorUtils {
@@ -34,5 +36,19 @@ public static JFieldVar addGetter(
     return instanceField;
   }
 
+  public static JFieldVar addOptionalGetter(
+      JDefinedClass definedClass, JType type, NameHelper nameHelper, String name) {
+    JFieldVar instanceField =
+        definedClass.field(JMod.PRIVATE, type, nameHelper.getPropertyName(name, null));
+    JClass optionalRef = definedClass.owner().ref(Optional.class).narrow(type);
+    JMethod method =
+        definedClass.method(JMod.PUBLIC, optionalRef, nameHelper.getGetterName(name, type, null));
+    method
+        .body()
+        ._return(
+            definedClass.owner().ref(Optional.class).staticInvoke("ofNullable").arg(instanceField));
+    return instanceField;
+  }
+
   private GeneratorUtils() {}
 }

pom.xml

@@ -114,6 +114,11 @@
         <artifactId>jackson-core</artifactId>
         <version>${version.com.fasterxml.jackson}</version>
       </dependency>
+      <dependency>
+        <groupId>com.fasterxml.jackson.datatype</groupId>
+        <artifactId>jackson-datatype-jdk8</artifactId>
+        <version>${version.com.fasterxml.jackson}</version>
+      </dependency>
       <dependency>
         <groupId>com.fasterxml.jackson.core</groupId>
         <artifactId>jackson-databind</artifactId>