Add helper function to facilitate use of library with oneOf types by selecting current type of item instead of checking all of them

Add Interface and Implement it

Add assignment on constructor

Author: uasouz

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

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.serverlessworkflow.api;
+
+public interface OneOfValueProvider {
+  Object get();
+}

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

@@ -34,12 +34,14 @@ 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");
+    if (task.get() instanceof CallTask) {
+      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");
+    }
   }
 }

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

@@ -31,6 +31,7 @@
 import com.sun.codemodel.JMod;
 import com.sun.codemodel.JPackage;
 import com.sun.codemodel.JType;
+import com.sun.codemodel.JVar;
 import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.net.URLDecoder;
@@ -102,13 +103,27 @@ private boolean isCandidateForCreation(Collection<JType> unionTypes) {
 
   private JDefinedClass populateClass(
       JDefinedClass definedClass, Optional<JType> refType, Collection<JType> unionTypes) {
-    unionTypes.forEach(unionType -> wrapIt(definedClass, unionType));
+    JType clazzClass = definedClass.owner()._ref(Object.class);
+
+    JFieldVar valueField =
+        definedClass.field(
+            JMod.PRIVATE,
+            clazzClass,
+            ruleFactory.getNameHelper().getPropertyName("value", null),
+            null);
+
+    definedClass._implements(
+        definedClass.owner().ref(GeneratorUtils.ONE_OF_VALUE_PROVIDER_INTERFACE_NAME));
+
+    GeneratorUtils.implementInterface(definedClass, valueField);
+
+    unionTypes.forEach(unionType -> wrapIt(definedClass, valueField, unionType));
     refType.ifPresent(
         type -> {
           if (type instanceof JClass) {
             definedClass._extends((JClass) type);
           } else {
-            wrapIt(definedClass, type);
+            wrapIt(definedClass, valueField, type);
           }
         });
     if (definedClass.constructors().hasNext()
@@ -166,23 +181,25 @@ private JDefinedClass createUnionClass(
       definedClass
           .annotate(JsonDeserialize.class)
           .param("using", generateDeserializer(definedClass, unionTypes));
+
       return populateClass(definedClass, refType, unionTypes);
     } catch (JClassAlreadyExistsException e) {
       throw new IllegalArgumentException(e);
     }
   }
 
-  private void wrapIt(JDefinedClass definedClass, JType unionType) {
+  private void wrapIt(JDefinedClass definedClass, JFieldVar valueField, JType unionType) {
     final String name = unionType.name();
     JFieldVar instanceField =
         definedClass.field(
             JMod.PRIVATE, unionType, ruleFactory.getNameHelper().getPropertyName(name, null));
     GeneratorUtils.buildMethod(definedClass, instanceField, ruleFactory.getNameHelper(), name);
     JMethod constructor = definedClass.constructor(JMod.PUBLIC);
+    JVar instanceParam = constructor.param(unionType, instanceField.name());
     constructor
         .body()
-        .assign(
-            JExpr._this().ref(instanceField), constructor.param(unionType, instanceField.name()));
+        .assign(JExpr._this().ref(valueField), instanceParam)
+        .assign(JExpr._this().ref(instanceField), instanceParam);
   }
 
   private void unionType(

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

@@ -36,6 +36,8 @@ public class GeneratorUtils {
       "io.serverlessworkflow.serialization.SerializeHelper";
   public static final String DESERIALIZE_HELPER_NAME =
       "io.serverlessworkflow.serialization.DeserializeHelper";
+  public static final String ONE_OF_VALUE_PROVIDER_INTERFACE_NAME =
+      "io.serverlessworkflow.api.OneOfValueProvider";
 
   @FunctionalInterface
   public interface SerializerFiller {
@@ -55,6 +57,13 @@ public static JDefinedClass deserializerClass(JDefinedClass relatedClass) {
     return createClass(relatedClass, JsonDeserializer.class, "Deserializer");
   }
 
+  public static JMethod implementInterface(JDefinedClass definedClass, JFieldVar valueField) {
+    JMethod method = definedClass.method(JMod.PUBLIC, Object.class, "get");
+    method.annotate(Override.class);
+    method.body()._return(valueField);
+    return method;
+  }
+
   public static JMethod buildMethod(
       JDefinedClass definedClass, JFieldVar instanceField, NameHelper nameHelper, String name) {
     JMethod method =