[BUGFIX] Suppress no-properties warning when domain object is inline FK target

The validation warning added in #812 fired for all domain objects with no
own properties, including those that are the target of a ZeroToMany inline
relation. For these objects the template correctly generates a CREATE TABLE
(via the FK column condition added in the same PR), so the warning message
was factually incorrect.

Fix: only emit the warning when the domain object has neither own properties
nor any incoming inline FK relation.

Also adds a unit test covering the suppressed-warning case.

Author: PKuhlmay

Classes/Domain/Validator/ExtensionValidator.php

@@ -550,7 +550,7 @@ private function validateDomainObjects(Extension $extension): void
                 );
             }
 
-            if (!count($domainObject->getProperties())) {
+            if (!count($domainObject->getProperties()) && !$this->hasIncomingFkRelation($domainObject, $extension)) {
                 $this->validationResult['warnings'][] = new ExtensionException(
                     'Domain object "' . $domainObject->getName() . '" has no properties.' . LF
                     . 'Without properties, no CREATE TABLE statement will be generated in ext_tables.sql.' . LF
@@ -579,6 +579,26 @@ private function validateDomainObjects(Extension $extension): void
         }
     }
 
+    /**
+     * Returns true if any other domain object in the extension has an inline ZeroToMany relation
+     * pointing to $domainObject, meaning a FK column will be generated in ext_tables.sql even
+     * when $domainObject has no own properties.
+     */
+    private function hasIncomingFkRelation(DomainObject $domainObject, Extension $extension): bool
+    {
+        foreach ($extension->getDomainObjects() as $otherObject) {
+            foreach ($otherObject->getProperties() as $property) {
+                if ($property instanceof ZeroToManyRelation
+                    && $property->getRenderType() === 'inline'
+                    && $property->getForeignClassName() === $domainObject->getFullQualifiedClassName()
+                ) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     /**
      * cover all cases:
      * 1. extend TYPO3 class like fe_users (no mapping table needed)

Tests/Unit/Domain/Validator/ValidationServiceTest.php

@@ -18,6 +18,7 @@
 namespace EBT\ExtensionBuilder\Tests\Unit\Domain\Validator;
 
 use EBT\ExtensionBuilder\Domain\Exception\ExtensionException;
+use EBT\ExtensionBuilder\Domain\Model\DomainObject\Relation\ZeroToManyRelation;
 use EBT\ExtensionBuilder\Domain\Validator\ExtensionValidator;
 use EBT\ExtensionBuilder\Tests\BaseUnitTest;
 
@@ -51,6 +52,32 @@ public function validateExtensionWarnsForDomainObjectWithNoProperties(): void
         );
     }
 
+    /**
+     * @test
+     */
+    public function noWarningForDomainObjectWithNoPropertiesWhenItIsInlineFkTarget(): void
+    {
+        $ownerObject = $this->buildDomainObject('OwnerModel', true, true);
+        $childObject = $this->buildDomainObject('ChildModel', true);
+        // child has no own properties, but is target of an inline ZeroToMany relation
+        $relation = new ZeroToManyRelation('children');
+        $relation->setForeignModel($childObject);
+        $relation->setRenderType('inline');
+        $ownerObject->addProperty($relation);
+        $this->extension->addDomainObject($ownerObject);
+        $this->extension->addDomainObject($childObject);
+
+        $extensionValidator = new ExtensionValidator();
+        $result = $extensionValidator->validateExtension($this->extension);
+
+        $warningCodes = array_map(fn($w) => $w->getCode(), $result['warnings']);
+        self::assertNotContains(
+            ExtensionValidator::ERROR_DOMAINOBJECT_NO_PROPERTIES,
+            $warningCodes,
+            'No warning expected for child model that is target of an inline FK relation'
+        );
+    }
+
     /**
      * @test
      */