Fix SubmodelElement XML ordering and Operation entity serialization (#456, #390)

- Fix SubmodelElementMixin property order to match XSD requirements
- Change "hasExtensions" to "extensions" and "qualifier" to "qualifiers"
- Remove duplicate properties from SubmodelElement ordering
- Add OperationVariable empty list handling to prevent invalid XML
- Remove test skip logic as all 2,593 XML validation tests now pass

Signed-off-by: Hannes Stiebitzhofer <hannes@stiebitzhofer.com>

Author: stiebitzhofer

dataformat-xml/src/main/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/xml/internal/mixins/SubmodelElementMixin.java

@@ -18,7 +18,7 @@
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 @JsonPropertyOrder({
-  "hasExtensions",
+  "extensions",
   "category",
   "idShort",
   "displayName",
@@ -27,9 +27,7 @@
   "kind", // --> HasKind
   "semanticId",
   "supplementalSemanticIds",
-  "reference", // --> HasSemantics
-  "qualifier", // --> Qualifiable
-  "dataSpecifications",
+  "qualifiers", // --> Qualifiable
   "embeddedDataSpecifications", // --> HasDataSpecifications
   "orderRelevant",
   "semanticIdListElement",

dataformat-xml/src/main/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/xml/internal/serialization/OperationVariableSerializer.java

@@ -20,6 +20,8 @@
 import com.fasterxml.jackson.databind.SerializerProvider;
 import com.fasterxml.jackson.dataformat.xml.ser.ToXmlGenerator;
 import java.io.IOException;
+import java.util.List;
+import org.eclipse.digitaltwin.aas4j.v3.dataformat.core.internal.util.ReflectionHelper;
 import org.eclipse.digitaltwin.aas4j.v3.dataformat.xml.internal.SubmodelElementManager;
 import org.eclipse.digitaltwin.aas4j.v3.model.OperationVariable;
 
@@ -29,12 +31,15 @@ public void serialize(
       OperationVariable operationVariable, JsonGenerator gen, SerializerProvider serializers)
       throws IOException {
     ToXmlGenerator xgen = (ToXmlGenerator) gen;
+    List<Runnable> resetRunnables =
+        ReflectionHelper.setEmptyListsToNull(operationVariable.getValue());
     xgen.writeStartObject();
     xgen.writeFieldName("value");
     xgen.writeStartObject();
     xgen.writeFieldName(SubmodelElementManager.getXmlName(operationVariable.getValue().getClass()));
     xgen.writeObject(operationVariable.getValue());
     xgen.writeEndObject();
     xgen.writeEndObject();
+    resetRunnables.stream().forEach(r -> r.run());
   }
 }

dataformat-xml/src/test/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/xml/XmlSerializerTest.java

@@ -40,6 +40,7 @@
 import org.eclipse.digitaltwin.aas4j.v3.model.DataTypeDefXsd;
 import org.eclipse.digitaltwin.aas4j.v3.model.DataTypeIec61360;
 import org.eclipse.digitaltwin.aas4j.v3.model.DefaultDummyDataSpecification;
+import org.eclipse.digitaltwin.aas4j.v3.model.EntityType;
 import org.eclipse.digitaltwin.aas4j.v3.model.Environment;
 import org.eclipse.digitaltwin.aas4j.v3.model.KeyTypes;
 import org.eclipse.digitaltwin.aas4j.v3.model.ReferenceTypes;
@@ -48,6 +49,7 @@
 import org.eclipse.digitaltwin.aas4j.v3.model.impl.DefaultAssetInformation;
 import org.eclipse.digitaltwin.aas4j.v3.model.impl.DefaultDataSpecificationIec61360;
 import org.eclipse.digitaltwin.aas4j.v3.model.impl.DefaultEmbeddedDataSpecification;
+import org.eclipse.digitaltwin.aas4j.v3.model.impl.DefaultEntity;
 import org.eclipse.digitaltwin.aas4j.v3.model.impl.DefaultEnvironment;
 import org.eclipse.digitaltwin.aas4j.v3.model.impl.DefaultExtension;
 import org.eclipse.digitaltwin.aas4j.v3.model.impl.DefaultKey;
@@ -214,6 +216,32 @@ public void validateMinimalOperationAgainstXsdSchema()
     assertTrue(errors.isEmpty());
   }
 
+  @Test
+  public void validateOperationEntityWithoutStatementsAgainstXsdSchema()
+      throws SerializationException, SAXException {
+    Submodel object =
+        new DefaultSubmodel.Builder()
+            .id("testSubmodel")
+            .idShort("testSubmodel")
+            .submodelElements(
+                new DefaultOperation.Builder()
+                    .idShort("operationToTest")
+                    .inputVariables(
+                        new DefaultOperationVariable.Builder()
+                            .value(
+                                new DefaultEntity.Builder()
+                                    .idShort("entityInput")
+                                    .entityType(EntityType.SELF_MANAGED_ENTITY)
+                                    .build())
+                            .build())
+                    .build())
+            .build();
+    String xml =
+        new XmlSerializer().write(new DefaultEnvironment.Builder().submodels(object).build());
+    Set<String> errors = validateAgainstXsdSchema(xml);
+    assertTrue(errors.isEmpty());
+  }
+
   @Test
   public void validateOperationWithMetadataAgainstXsdSchema()
       throws SerializationException, SAXException {

dataformat-xml/src/test/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/xml/XmlValidationTest.java

@@ -17,13 +17,11 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assume.assumeFalse;
 
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.List;
 import java.util.Set;
 import java.util.stream.Stream;
 import junitparams.JUnitParamsRunner;
@@ -47,26 +45,6 @@ public class XmlValidationTest {
   private static XmlSchemaValidator validator;
   private static final String TEST_FILES_DIR = "target/test-classes/examples";
 
-  // List of tests that are known to have issues with EmbeddedDataSpecificationsDeserializer ->
-  // GitHub issue https://github.com/eclipse-aas4j/aas4j/issues/389 and
-  // https://github.com/eclipse-aas4j/aas4j/issues/390
-  private static final List<String> IGNORED_TESTS =
-      List.of(
-          "annotatedRelationshipElement",
-          "basicEventElement",
-          "blob",
-          "capability",
-          "entity",
-          "file",
-          "multiLanguageProperty",
-          "operation",
-          "property",
-          "range",
-          "referenceElement",
-          "relationshipElement",
-          "submodelElementCollection",
-          "submodelElementList");
-
   @BeforeClass
   public static void prepareValidator() throws SAXException {
     validator = new XmlSchemaValidator();
@@ -103,15 +81,6 @@ public void validateInvalidXml(String file) throws IOException {
   public void validateExampleXml(String filePath)
       throws DeserializationException, SerializationException, IOException {
 
-    // Skip tests that are known to have issues with EmbeddedDataSpecificationsDeserializer ->
-    // GitHub issue https://github.com/eclipse-aas4j/aas4j/issues/389 and
-    // https://github.com/eclipse-aas4j/aas4j/issues/390
-    boolean shouldSkip = IGNORED_TESTS.stream().anyMatch(filePath::contains);
-
-    assumeFalse(
-        "Skipping the tests because of EmbeddedDataSpecificationsDeserializer issue:" + filePath,
-        shouldSkip);
-
     String initialXml = new String(Files.readAllBytes(Paths.get(filePath)));
 
     Environment environment = new XmlDeserializer().read(initialXml);