feat: If a transformer throws RefuseToHandleException, the `MainTra…

…nsformer` will try the next suitable transformer.

CHANGELOG.md

@@ -9,6 +9,8 @@
   exceptions.
 * feat: Main transformer's exception now accepts `$context` variable.
 * feat: More useful `TransformerReturnsUnexpectedValueException` exception message.
+* feat: If a transformer throws `RefuseToHandleException`, the `MainTransformer`
+  will try the next suitable transformer.
 
 ## 0.5.8
 

src/MainTransformer/MainTransformer.php

@@ -24,6 +24,7 @@
 use Rekalogika\Mapper\Transformer\Contracts\MainTransformerAwareInterface;
 use Rekalogika\Mapper\Transformer\Contracts\MixedType;
 use Rekalogika\Mapper\Transformer\Contracts\TransformerInterface;
+use Rekalogika\Mapper\Transformer\Exception\RefuseToHandleException;
 use Rekalogika\Mapper\TransformerRegistry\TransformerRegistryInterface;
 use Rekalogika\Mapper\TypeResolver\TypeResolverInterface;
 use Rekalogika\Mapper\Util\TypeCheck;
@@ -163,20 +164,23 @@ public function transform(
 
             // transform the source to the target
 
-            /** @var mixed */
-            $result = $transformer->transform(
-                source: $source,
-                target: $target,
-                sourceType: $sourceTypeForTransformer,
-                targetType: $targetTypeForTransformer,
-                context: $context
-            );
+            try {
+                /** @var mixed */
+                $result = $transformer->transform(
+                    source: $source,
+                    target: $target,
+                    sourceType: $sourceTypeForTransformer,
+                    targetType: $targetTypeForTransformer,
+                    context: $context
+                );
+            } catch (RefuseToHandleException) {
+                continue;
+            }
 
             // check the result type
 
             if (
                 !TypeCheck::isVariableInstanceOf($result, $targetType)
-                && $result !== null
             ) {
                 throw new TransformerReturnsUnexpectedValueException($source, $targetType, $result, $transformer, $context);
             }

src/Transformer/CopyTransformer.php

@@ -17,6 +17,8 @@
 use Rekalogika\Mapper\Transformer\Contracts\MixedType;
 use Rekalogika\Mapper\Transformer\Contracts\TransformerInterface;
 use Rekalogika\Mapper\Transformer\Contracts\TypeMapping;
+use Rekalogika\Mapper\Transformer\Exception\RefuseToHandleException;
+use Rekalogika\Mapper\Util\TypeCheck;
 use Symfony\Component\PropertyInfo\Type;
 
 final class CopyTransformer implements TransformerInterface
@@ -37,7 +39,14 @@ public function transform(
         if (!$clonable) {
             return $source;
         }
-        return clone $source;
+
+        $result = clone $source;
+
+        if ($targetType !== null && !TypeCheck::isVariableInstanceOf($result, $targetType)) {
+            throw new RefuseToHandleException();
+        }
+
+        return $result;
     }
 
     public function getSupportedTransformation(): iterable

src/Transformer/Exception/RefuseToHandleException.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of rekalogika/mapper package.
+ *
+ * (c) Priyadi Iman Nurcahyo <https://rekalogika.dev>
+ *
+ * For the full copyright and license information, please view the LICENSE file
+ * that was distributed with this source code.
+ */
+
+namespace Rekalogika\Mapper\Transformer\Exception;
+
+use Rekalogika\Mapper\Exception\RuntimeException;
+
+/**
+ * If a transformer throw this exception, it means that the transformer is not
+ * able to handle the given source type in an ad-hoc basis. The main transformer
+ * will try the next transformer for the task.
+ */
+class RefuseToHandleException extends RuntimeException
+{
+}