[Fix #1333] Fixing WorkflowModelCollection serialization/deserialization

experimental/model/src/main/java/io/serverlessworkflow/impl/model/func/JavaModelCollection.java

@@ -22,6 +22,7 @@
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 
 public class JavaModelCollection implements Collection<WorkflowModel>, WorkflowModelCollection {
@@ -156,4 +157,17 @@ public <T> Optional<T> as(Class<T> clazz) {
 
     return CollectionConversionUtils.as(object, clazz);
   }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(object);
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) return true;
+    if (!(obj instanceof JavaModelCollection)) return false;
+    JavaModelCollection other = (JavaModelCollection) obj;
+    return Objects.equals(object, other.object);
+  }
 }

experimental/model/src/main/java/io/serverlessworkflow/impl/model/func/JavaModelCollectionMarshaller.java

@@ -0,0 +1,45 @@
+/*
+ * 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.impl.model.func;
+
+import io.serverlessworkflow.impl.marshaller.CustomObjectMarshaller;
+import io.serverlessworkflow.impl.marshaller.WorkflowInputBuffer;
+import io.serverlessworkflow.impl.marshaller.WorkflowOutputBuffer;
+import java.util.Collection;
+
+public class JavaModelCollectionMarshaller implements CustomObjectMarshaller<JavaModelCollection> {
+
+  @Override
+  public void write(WorkflowOutputBuffer buffer, JavaModelCollection object) {
+    buffer.writeObject(object.asJavaObject());
+  }
+
+  @Override
+  public JavaModelCollection read(
+      WorkflowInputBuffer buffer, Class<? extends JavaModelCollection> clazz) {
+    return new JavaModelCollection((Collection<?>) buffer.readObject());
+  }
+
+  @Override
+  public Class<JavaModelCollection> getObjectClass() {
+    return JavaModelCollection.class;
+  }
+
+  @Override
+  public int priority() {
+    return Integer.MAX_VALUE;
+  }
+}

experimental/model/src/main/resources/META-INF/services/io.serverlessworkflow.impl.marshaller.CustomObjectMarshaller

@@ -1,2 +1,3 @@
 io.serverlessworkflow.impl.model.func.JavaModelMarshaller
+io.serverlessworkflow.impl.model.func.JavaModelCollectionMarshaller
 io.serverlessworkflow.impl.model.func.SerializableObjectMarshaller

experimental/model/src/test/java/io/serverlessworkflow/impl/model/func/JavaModelSerializationTest.java

@@ -23,6 +23,7 @@
 import io.serverlessworkflow.impl.marshaller.WorkflowOutputBuffer;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.util.List;
 import org.junit.jupiter.api.Test;
 
 class JavaModelSerializationTest {
@@ -33,6 +34,13 @@ void testSerializableJavaModel() {
         new JavaModel(new Person("Pepe Gotera", 32, new Address("Rue del Percebe", 13))));
   }
 
+  @Test
+  void testSerializableJavaModelCollection() {
+    testMarshallUnMarshall(
+        new JavaModelCollection(
+            List.of(new Person("Pepe Gotera", 32, new Address("Rue del Percebe", 13)))));
+  }
+
   private void testMarshallUnMarshall(Object object) {
     WorkflowBufferFactory factory = DefaultBufferFactory.factory();
     ByteArrayOutputStream output = new ByteArrayOutputStream();

impl/core/src/main/java/io/serverlessworkflow/impl/marshaller/AbstractOutputBuffer.java

@@ -15,6 +15,7 @@
  */
 package io.serverlessworkflow.impl.marshaller;
 
+import io.serverlessworkflow.impl.WorkflowModel;
 import java.time.Instant;
 import java.util.Collection;
 import java.util.Map;
@@ -64,6 +65,8 @@ public WorkflowOutputBuffer writeCollection(Collection<Object> col) {
   public WorkflowOutputBuffer writeObject(Object object) {
     if (object == null) {
       writeType(Type.NULL);
+    } else if (object instanceof WorkflowModel) {
+      internalWriteObject(object);
     } else if (object instanceof Short number) {
       writeType(Type.SHORT);
       writeShort(number);
@@ -101,8 +104,7 @@ public WorkflowOutputBuffer writeObject(Object object) {
       writeType(Type.BYTES);
       writeBytes(bytes);
     } else {
-      writeType(Type.CUSTOM);
-      writeCustomObject(object);
+      internalWriteObject(object);
     }
     return this;
   }
@@ -111,6 +113,11 @@ protected void writeClass(Class<?> objectClass) {
     writeString(objectClass.getCanonicalName());
   }
 
+  private void internalWriteObject(Object object) {
+    writeType(Type.CUSTOM);
+    writeCustomObject(object);
+  }
+
   @SuppressWarnings({"rawtypes", "unchecked"})
   protected void writeCustomObject(Object object) {
     Class<?> objectClass = object.getClass();

impl/model/src/main/java/io/serverlessworkflow/impl/model/jackson/JacksonModelCollection.java

@@ -16,6 +16,8 @@
 package io.serverlessworkflow.impl.model.jackson;
 
 import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import io.serverlessworkflow.impl.CollectionConversionUtils;
 import io.serverlessworkflow.impl.WorkflowModel;
@@ -25,11 +27,14 @@
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 
+@JsonSerialize(using = JacksonModelCollectionSerializer.class)
+@JsonDeserialize(using = JacksonModelCollectionDeserializer.class)
 public class JacksonModelCollection implements WorkflowModelCollection {
 
-  private ArrayNode node;
+  protected ArrayNode node;
 
   JacksonModelCollection() {
     this.node = JsonUtils.array();
@@ -164,4 +169,17 @@ public Object asJavaObject() {
   public Class<?> objectClass() {
     return ArrayNode.class;
   }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(node);
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) return true;
+    if (!(obj instanceof JacksonModelCollection)) return false;
+    JacksonModelCollection other = (JacksonModelCollection) obj;
+    return Objects.equals(node, other.node);
+  }
 }

impl/model/src/main/java/io/serverlessworkflow/impl/model/jackson/JacksonModelCollectionDeserializer.java

@@ -0,0 +1,37 @@
+/*
+ * 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.impl.model.jackson;
+
+import com.fasterxml.jackson.core.JacksonException;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import java.io.IOException;
+
+public class JacksonModelCollectionDeserializer extends StdDeserializer<JacksonModelCollection> {
+
+  private static final long serialVersionUID = 1L;
+
+  protected JacksonModelCollectionDeserializer() {
+    super(JacksonModelCollection.class);
+  }
+
+  @Override
+  public JacksonModelCollection deserialize(JsonParser p, DeserializationContext ctxt)
+      throws IOException, JacksonException {
+    return new JacksonModelCollection(p.readValueAsTree());
+  }
+}

impl/model/src/main/java/io/serverlessworkflow/impl/model/jackson/JacksonModelCollectionMarshaller.java

@@ -0,0 +1,25 @@
+/*
+ * 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.impl.model.jackson;
+
+public class JacksonModelCollectionMarshaller
+    extends AbstractJacksonMarshaller<JacksonModelCollection> {
+
+  @Override
+  public Class<JacksonModelCollection> getObjectClass() {
+    return JacksonModelCollection.class;
+  }
+}

impl/model/src/main/java/io/serverlessworkflow/impl/model/jackson/JacksonModelCollectionSerializer.java

@@ -0,0 +1,37 @@
+/*
+ * 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.impl.model.jackson;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import java.io.IOException;
+
+public class JacksonModelCollectionSerializer extends StdSerializer<JacksonModelCollection> {
+
+  private static final long serialVersionUID = 1L;
+
+  protected JacksonModelCollectionSerializer() {
+    super(JacksonModelCollection.class);
+  }
+
+  @Override
+  public void serialize(
+      JacksonModelCollection value, JsonGenerator gen, SerializerProvider provider)
+      throws IOException {
+    gen.writeTree(value.node);
+  }
+}

impl/model/src/main/resources/META-INF/services/io.serverlessworkflow.impl.marshaller.CustomObjectMarshaller

@@ -1,2 +1,3 @@
 io.serverlessworkflow.impl.model.jackson.JacksonModelMarshaller
+io.serverlessworkflow.impl.model.jackson.JacksonModelCollectionMarshaller
 io.serverlessworkflow.impl.model.jackson.JacksonObjectMarshaller

impl/model/src/test/java/io/serverlessworkflow/impl/model/jackson/JacksonModelSerializationTest.java

@@ -39,6 +39,16 @@ void testModel() {
         new JacksonModel(JsonUtils.mapper().createObjectNode().put("Mortadelo", "TIA")));
   }
 
+  @Test
+  void testCollectionModel() {
+    testMarshallUnMarshall(
+        new JacksonModelCollection(
+            JsonUtils.mapper()
+                .createArrayNode()
+                .add(JsonUtils.mapper().createObjectNode().put("Mortadelo", "TIA"))));
+    testMarshallUnMarshall(new JacksonModelCollection(JsonUtils.mapper().createArrayNode().add(1)));
+  }
+
   private void testMarshallUnMarshall(Object object) {
     WorkflowBufferFactory factory = DefaultBufferFactory.factory();
     ByteArrayOutputStream output = new ByteArrayOutputStream();