Fixes bug in java code generation in case an entity has no property, but extends another entity.

This leaded to an error in the hashCode generation.

Author: DvSmi

core/sds-aspect-model-java-generator/src/main/java/io/openmanufacturing/sds/aspectmodel/java/AspectModelJavaUtil.java

@@ -535,11 +535,15 @@ public static String objectEqualsExpression( final StructureElement element ) {
             .collect( Collectors.joining( " && " ) );
    }
 
-   public static String objectsHashCodeExpression( final StructureElement element ) {
-      return element.getProperties().stream()
+   public static String objectsHashCodeExpression( final StructureElement element, final boolean needsLeadingComma ) {
+      final String elementString = element.getProperties().stream()
             .filter( property -> !property.isAbstract() )
             .map( Property::getPayloadName )
             .collect( Collectors.joining( ", " ) );
+      if ( StringUtils.isNotBlank( elementString ) && needsLeadingComma ) {
+         return ", " + elementString;
+      }
+      return elementString;
    }
 
    /**

core/sds-aspect-model-java-generator/src/main/resources/java-pojo-hashcode-method-lib.vm

@@ -1,14 +1,18 @@
 #macro( javaPojoHashCodeMethod )
 @Override
 public int hashCode() {
-    return Objects.hash(
+return Objects.hash(
     #if ( $element.is( $ComplexType ) )
         #set( $complexElement = $ComplexType.cast( $element ) )
         #if ( $complexElement.getExtends().isPresent() )
-            super.hashCode(),
+        super.hashCode()
+            ${util.objectsHashCodeExpression( $element, true )}
+        #else
+            ${util.objectsHashCodeExpression( $element, false )}
         #end
+    #else
+        ${util.objectsHashCodeExpression( $element, false )}
     #end
-    ${util.objectsHashCodeExpression( $element )}
-    );
+);
 }
 #end

core/sds-test-aspect-models/src/main/java/io/openmanufacturing/sds/test/TestAspect.java

@@ -70,6 +70,7 @@ public enum TestAspect implements TestModel {
    ASPECT_WITH_ENGLISH_AND_GERMAN_DESCRIPTION,
    ASPECT_WITH_ENGLISH_DESCRIPTION,
    ASPECT_WITH_ENTITY,
+   ASPECT_WITH_ENTITY_WITHOUT_PROPERTY,
    ASPECT_WITH_ENTITY_COLLECTION,
    ASPECT_WITH_ENTITY_ENUMERATION,
    ASPECT_WITH_ENTITY_ENUMERATION_AND_LANG_STRING,

core/sds-test-aspect-models/src/main/resources/valid/bamm_2_0_0/io.openmanufacturing.test/1.0.0/AspectWithEntityWithoutProperty.ttl

@@ -0,0 +1,58 @@
+    # Copyright (c) 2021 Robert Bosch Manufacturing Solutions GmbH
+#
+# See the AUTHORS file(s) distributed with this work for additional
+# information regarding authorship.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# SPDX-License-Identifier: MPL-2.0
+
+@prefix :       <urn:bamm:io.openmanufacturing.test:1.0.0#> .
+@prefix bamm:   <urn:bamm:io.openmanufacturing:meta-model:2.0.0#> .
+@prefix bamm-c: <urn:bamm:io.openmanufacturing:characteristic:2.0.0#> .
+@prefix xsd:    <http://www.w3.org/2001/XMLSchema#> .
+@prefix unit:   <urn:bamm:io.openmanufacturing:unit:2.0.0#> .
+
+:AspectWithEntity
+    a                  bamm:Aspect ;
+    bamm:preferredName "Test Aspect"@en ;
+    bamm:description   "This is a test description"@en ;
+    bamm:see           <http://example.com/omp> ;
+    bamm:properties    ( :testProperty ) ;
+    bamm:operations    ( ) .
+
+:testProperty
+    a                   bamm:Property ;
+    bamm:preferredName  "Test Property"@en ;
+    bamm:description    "This is a test property."@en ;
+    bamm:see            <http://example.com/omp> ;
+    bamm:see            <http://example.com/me> ;
+    bamm:characteristic :EntityCharacteristic .
+
+:EntityCharacteristic
+    a                  bamm-c:SingleEntity ;
+    bamm:preferredName "Test Entity Characteristic"@en ;
+    bamm:description   "This is a test Entity Characteristic"@en ;
+    bamm:see           <http://example.com/omp> ;
+    bamm:dataType      :TestEntity .
+
+:TestEntity
+    a                  bamm:Entity ;
+    bamm:extends       :AbstractEntity ;
+    bamm:preferredName "Test Entity"@en ;
+    bamm:description   "This is a test entity"@en ;
+    bamm:properties    ( ) .
+
+:AbstractEntity
+    a                  bamm-c:AbstractEntity ;
+    bamm:preferredName "Abstract test Entity"@en ;
+    bamm:description   "This is an abstract test entity"@en ;
+    bamm:properties    ( :entityProperty ) .
+
+:entityProperty
+    a                   bamm:Property ;
+    bamm:preferredName  "Entity Property"@en ;
+    bamm:description    "This is a property for the test entity."@en ;
+    bamm:characteristic bamm-c:Text .