fix: turn NewInstanceReturnedButCannotBeSetOnTargetException into a warning

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * feat: `Map` now accepts false, for the more expressive `#[Map(false)]`
 * refactor: remove property processor for easier future optimization
+* fix: turn `NewInstanceReturnedButCannotBeSetOnTargetException` into a warning
 
 ## 1.13.1
 

config/services.php

@@ -389,6 +389,7 @@
             '$subMapperFactory' => service('rekalogika.mapper.sub_mapper.factory'),
             '$proxyFactory' => service('rekalogika.mapper.proxy.factory'),
             '$propertyAccessor' => service(PropertyAccessorInterface::class),
+            '$logger' => service(LoggerInterface::class),
         ]);
 
     # sub mapper

src/MapperFactory.php

@@ -15,6 +15,8 @@
 
 use Psr\Cache\CacheItemPoolInterface;
 use Psr\Container\ContainerInterface;
+use Psr\Log\LoggerInterface;
+use Psr\Log\NullLogger;
 use Ramsey\Uuid\UuidInterface;
 use Rekalogika\Mapper\Command\MappingCommand;
 use Rekalogika\Mapper\Command\TryCommand;
@@ -209,6 +211,8 @@ class MapperFactory
 
     private ?Application $application = null;
 
+    private LoggerInterface $logger;
+
     /**
      * @param array<string,TransformerInterface> $additionalTransformers
      */
@@ -219,7 +223,10 @@ public function __construct(
         private readonly ?NormalizerInterface $normalizer = null,
         private readonly ?DenormalizerInterface $denormalizer = null,
         private readonly CacheItemPoolInterface $propertyInfoExtractorCache = new ArrayAdapter(),
-    ) {}
+        ?LoggerInterface $logger = null,
+    ) {
+        $this->logger = $logger ?? new NullLogger();
+    }
 
     /**
      * @param class-string $sourceClass
@@ -907,6 +914,7 @@ protected function getObjectProcessorFactory(): ObjectProcessorFactoryInterface
             subMapperFactory: $this->getSubMapperFactory(),
             proxyFactory: $this->getProxyFactory(),
             propertyAccessor: $this->getPropertyAccessor(),
+            logger: $this->logger,
         );
     }
 

src/Transformer/Processor/ObjectProcessor/DefaultObjectProcessorFactory.php

@@ -14,6 +14,7 @@
 namespace Rekalogika\Mapper\Transformer\Processor\ObjectProcessor;
 
 use Psr\Container\ContainerInterface;
+use Psr\Log\LoggerInterface;
 use Rekalogika\Mapper\Proxy\ProxyFactoryInterface;
 use Rekalogika\Mapper\SubMapper\SubMapperFactoryInterface;
 use Rekalogika\Mapper\Transformer\MainTransformerAwareTrait;
@@ -34,6 +35,7 @@ public function __construct(
         private readonly SubMapperFactoryInterface $subMapperFactory,
         private readonly ProxyFactoryInterface $proxyFactory,
         private readonly PropertyAccessorInterface $propertyAccessor,
+        private readonly LoggerInterface $logger,
     ) {}
 
     public function getObjectProcessor(
@@ -46,6 +48,7 @@ public function getObjectProcessor(
             subMapperFactory: $this->subMapperFactory,
             proxyFactory: $this->proxyFactory,
             propertyAccessor: $this->propertyAccessor,
+            logger: $this->logger,
         );
     }
 }

src/Transformer/Processor/ObjectProcessor/ObjectProcessor.php

@@ -14,6 +14,7 @@
 namespace Rekalogika\Mapper\Transformer\Processor\ObjectProcessor;
 
 use Psr\Container\ContainerInterface;
+use Psr\Log\LoggerInterface;
 use Rekalogika\Mapper\Context\Context;
 use Rekalogika\Mapper\Context\ExtraTargetValues;
 use Rekalogika\Mapper\Context\MapperOptions;
@@ -26,7 +27,6 @@
 use Rekalogika\Mapper\Transformer\Exception\ClassNotInstantiableException;
 use Rekalogika\Mapper\Transformer\Exception\ExtraTargetPropertyNotFoundException;
 use Rekalogika\Mapper\Transformer\Exception\InstantiationFailureException;
-use Rekalogika\Mapper\Transformer\Exception\NewInstanceReturnedButCannotBeSetOnTargetException;
 use Rekalogika\Mapper\Transformer\Exception\UnableToReadException;
 use Rekalogika\Mapper\Transformer\Exception\UnableToWriteException;
 use Rekalogika\Mapper\Transformer\Exception\UninitializedSourcePropertyException;
@@ -56,6 +56,7 @@ public function __construct(
         private SubMapperFactoryInterface $subMapperFactory,
         private ProxyFactoryInterface $proxyFactory,
         private PropertyAccessorInterface $propertyAccessor,
+        private LoggerInterface $logger,
     ) {}
 
     public function transform(
@@ -989,15 +990,17 @@ public function writeTargetProperty(
             $visibility !== Visibility::Public
             || $writeMode === WriteMode::None
         ) {
-            if ($silentOnError) {
-                return $target;
+            if (!$silentOnError) {
+                $this->logger->warning(
+                    'Transformation of property "{property}" on target class "{class}" results in a different object instance from the original instance, but the new instance cannot be set on the target object. To fix the problem, you may 1. make the property public, 2. add a setter method for the property, or 3. add "#[Map(false)]" attribute on the property to skip the mapping.',
+                    [
+                        'property' => $metadata->getTargetProperty(),
+                        'class' => get_debug_type($target),
+                    ],
+                );
             }
 
-            throw new NewInstanceReturnedButCannotBeSetOnTargetException(
-                target: $target,
-                propertyName: $metadata->getTargetProperty(),
-                context: $context,
-            );
+            return $target;
         }
 
         if ($accessorName === null) {