Fix comma insertion processing nested Entities

Author: sekikn

core/esmf-aspect-model-document-generators/src/main/java/org/eclipse/esmf/aspectmodel/generator/sql/databricks/AspectModelDatabricksDenormalizedSqlVisitor.java

@@ -142,10 +142,12 @@ public String visitStructureElement( final StructureElement structureElement, fi
       final StringBuilder result = new StringBuilder();
       final Consumer<String> appendLine = line -> {
          if ( !line.isBlank() ) {
-            if ( !result.isEmpty() ) {
+            // Turning entire result into String for checking its contents can be ineffective,
+            // so we pick up the minimum substring here though it's verbose a bit.
+            if ( !result.isEmpty() && !result.substring( result.length() < 4 ? 0 : result.length() - 4 ).stripTrailing().endsWith( "," ) ) {
                result.append( ",\n" );
             }
-            if ( !line.startsWith( "  " ) ) {
+            if ( !line.startsWith( "  " ) && ( result.length() < 2 || !result.substring( result.length() - 2 ).equals( "  " ) ) ) {
                result.append( "  " );
             }
             result.append( line );
@@ -168,7 +170,10 @@ public String visitStructureElement( final StructureElement structureElement, fi
 
    @Override
    public String visitAspect( final Aspect aspect, final Context context ) {
-      final String columnDeclarations = visitStructureElement( aspect, context );
+      String columnDeclarations = visitStructureElement( aspect, context );
+      if ( columnDeclarations.endsWith( ",\n  " ) ) {
+         columnDeclarations = columnDeclarations.substring( 0, columnDeclarations.length() - 4 );
+      }
       final String comment = config.includeTableComment()
             ? Optional.ofNullable( aspect.getDescription( config.commentLanguage() ) ).map( description ->
             new DatabricksCommentDefinition( description ) + "\n" ).orElse( "" )
@@ -309,10 +314,6 @@ private String processComplexType( final ComplexType entity, final Context conte
          }
       } );
 
-      if ( !columns.isEmpty() && columns.toString().endsWith( ",\n  " ) ) {
-         columns.setLength( columns.length() - 4 ); // Remove last ",\n  "
-      }
-
       return columns.toString();
    }
 

core/esmf-aspect-model-document-generators/src/test/java/org/eclipse/esmf/aspectmodel/generator/sql/databricks/AspectModelDatabricksDenormalizedSqlVisitorTest.java

@@ -533,4 +533,16 @@ CREATE TABLE IF NOT EXISTS aspect_with_property_with_payload_name (
             TBLPROPERTIES ('x-samm-aspect-model-urn'='urn:samm:org.eclipse.esmf.test:1.0.0#AspectWithPropertyWithPayloadName');
             """ );
    }
+
+   @Test
+   void testAspectWithUpwardTransitionInNestedEntity() {
+      assertThat( sql( TestAspect.ASPECT_WITH_UPWARD_TRANSITION_IN_NESTED_ENTITY ) ).isEqualTo( """
+            CREATE TABLE IF NOT EXISTS aspect_with_upward_transition_in_nested_entity (
+              first_level_property__second_level_property1__third_level_property_id BIGINT NOT NULL,
+              first_level_property__second_level_property1__third_level_property STRING NOT NULL,
+              first_level_property__second_level_property2 STRING NOT NULL
+            )
+            TBLPROPERTIES ('x-samm-aspect-model-urn'='urn:samm:org.eclipse.esmf.test:1.0.0#AspectWithUpwardTransitionInNestedEntity');
+            """ );
+   }
 }

core/esmf-test-aspect-models/src/main/java/org/eclipse/esmf/test/TestAspect.java

@@ -192,6 +192,7 @@ public enum TestAspect implements TestModel {
    ASPECT_WITH_TWO_STRUCTURED_VALUES_AND_TRAIT,
    ASPECT_WITH_UMLAUT_DESCRIPTION,
    ASPECT_WITH_UNIT,
+   ASPECT_WITH_UPWARD_TRANSITION_IN_NESTED_ENTITY,
    ASPECT_WITH_USED_AND_UNUSED_CHARACTERISTIC,
    ASPECT_WITH_USED_AND_UNUSED_COLLECTION,
    ASPECT_WITH_USED_AND_UNUSED_CONSTRAINT,

core/esmf-test-aspect-models/src/main/resources/valid/org.eclipse.esmf.test/1.0.0/AspectWithUpwardTransitionInNestedEntity.ttl

@@ -0,0 +1,42 @@
+# Copyright (c) 2025 Contributors to the Eclipse Foundation
+#
+# 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:samm:org.eclipse.esmf.test:1.0.0#> .
+@prefix samm: <urn:samm:org.eclipse.esmf.samm:meta-model:2.2.0#> .
+@prefix samm-c: <urn:samm:org.eclipse.esmf.samm:characteristic:2.2.0#> .
+
+:AspectWithUpwardTransitionInNestedEntity a samm:Aspect ;
+   samm:properties ( :firstLevelProperty ) ;
+   samm:operations ( ) .
+
+:firstLevelProperty a samm:Property ;
+   samm:characteristic :FirstLevelCharacteristics .
+
+:FirstLevelCharacteristics a samm-c:List ;
+   samm:dataType :FirstLevelEntity .
+
+:FirstLevelEntity a samm:Entity ;
+   samm:properties ( :secondLevelProperty1 :secondLevelProperty2 ) .
+
+:secondLevelProperty1 a samm:Property ;
+   samm:characteristic :SecondLevelCharacteristics .
+
+:secondLevelProperty2 a samm:Property ;
+   samm:characteristic samm-c:Text .
+
+:SecondLevelCharacteristics a samm:Characteristic ;
+   samm:dataType :SecondLevelEntity .
+
+:SecondLevelEntity a samm:Entity ;
+   samm:properties ( :thirdLevelProperty ) .
+
+:thirdLevelProperty a samm:Property ;
+   samm:characteristic samm-c:Text .