fix(discriminator): don't use target to populate when there is a discriminator on target

Author: joelwurtz

src/Generator/CreateTargetStatementsGenerator.php

@@ -40,8 +40,10 @@ public function __construct(
      *    ... // create object statements
      * }
      * ```
+     *
+     * @return list<Stmt>
      */
-    public function generate(GeneratorMetadata $metadata, VariableRegistry $variableRegistry): Stmt
+    public function generate(GeneratorMetadata $metadata, VariableRegistry $variableRegistry): array
     {
         $createObjectStatements = [];
 
@@ -56,9 +58,18 @@ public function generate(GeneratorMetadata $metadata, VariableRegistry $variable
 
         $createObjectStatements = array_values(array_filter($createObjectStatements));
 
-        return new Stmt\If_(new Expr\BinaryOp\Identical(new Expr\ConstFetch(new Name('null')), $variableRegistry->getResult()), [
-            'stmts' => $createObjectStatements,
-        ]);
+        if ($this->canUseTargetToPopulate($metadata)) {
+            return [new Stmt\If_(new Expr\BinaryOp\Identical(new Expr\ConstFetch(new Name('null')), $variableRegistry->getResult()), [
+                'stmts' => $createObjectStatements,
+            ])];
+        }
+
+        return $createObjectStatements;
+    }
+
+    public function canUseTargetToPopulate(GeneratorMetadata $metadata): bool
+    {
+        return !$this->discriminatorStatementsGeneratorTarget->supports($metadata);
     }
 
     private function targetAsArray(GeneratorMetadata $metadata): ?Stmt

src/Generator/MapMethodStatementsGenerator.php

@@ -52,9 +52,13 @@ public function getStatements(GeneratorMetadata $metadata): array
 
         $statements = [$this->ifSourceIsNullReturnNull($metadata)];
         $statements = [...$statements, ...$this->handleCircularReference($metadata)];
-        $statements = [...$statements, ...$this->initializeTargetToPopulate($metadata)];
-        $statements = [...$statements, ...$this->initializeTargetFromProvider($metadata)];
-        $statements[] = $this->createObjectStatementsGenerator->generate($metadata, $variableRegistry);
+
+        if ($this->createObjectStatementsGenerator->canUseTargetToPopulate($metadata)) {
+            $statements = [...$statements, ...$this->initializeTargetToPopulate($metadata)];
+            $statements = [...$statements, ...$this->initializeTargetFromProvider($metadata)];
+        }
+
+        $statements = [...$statements, ...$this->createObjectStatementsGenerator->generate($metadata, $variableRegistry)];
 
         $addedDependenciesStatements = $this->handleDependencies($metadata);
 

src/Generator/Shared/DiscriminatorStatementsGenerator.php

@@ -122,8 +122,7 @@ public function createTargetStatements(GeneratorMetadata $metadata): array
         if (!$isDefinedExpression) {
             return $discriminateStatements;
         }
-        $cannotCreateTarget = ($metadata->mapperMetadata->targetReflectionClass?->isAbstract()
-            || $metadata->mapperMetadata->targetReflectionClass?->isInterface()) ?? false;
+        $cannotCreateTarget = !($metadata->mapperMetadata->targetReflectionClass === null) && !$metadata->mapperMetadata->targetReflectionClass->isInstantiable();
 
         $if = new Stmt\If_($isDefinedExpression, [
             'stmts' => $discriminateStatements,
@@ -140,7 +139,7 @@ public function createTargetStatements(GeneratorMetadata $metadata): array
         return $statements;
     }
 
-    private function supports(GeneratorMetadata $metadata): bool
+    public function supports(GeneratorMetadata $metadata): bool
     {
         if (!$this->classDiscriminatorResolver->hasClassDiscriminator($metadata, $this->fromSource)) {
             return false;

tests/AutoMapperTest/DiscriminatorPopulate/expected.data

@@ -0,0 +1,6 @@
+AutoMapper\Tests\AutoMapperTest\DiscriminatorPopulate\LinkWrapper {
+  +link: AutoMapper\Tests\AutoMapperTest\DiscriminatorPopulate\DefaultLinkType {
+    +link: "https://example.com/new"
+    +description: "description"
+  }
+}

tests/AutoMapperTest/DiscriminatorPopulate/map.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AutoMapper\Tests\AutoMapperTest\DiscriminatorPopulate;
+
+use AutoMapper\MapperContext;
+use AutoMapper\Tests\AutoMapperBuilder;
+use Symfony\Component\Serializer\Attribute\DiscriminatorMap;
+
+#[DiscriminatorMap('linkType', [
+    'default' => DefaultLinkType::class,
+])]
+abstract class LinkType
+{
+}
+
+class DefaultLinkType extends LinkType
+{
+    public function __construct(
+        public string $link,
+        public string $description = 'default',
+    ) {
+    }
+}
+
+class LinkWrapper
+{
+    public function __construct(
+        public LinkType $link,
+    ) {
+    }
+}
+
+$source = [
+    'link' => [
+        'linkType' => 'default',
+        'link' => 'https://example.com/new',
+    ],
+];
+
+$existingData = new LinkWrapper(new DefaultLinkType('https://example.com/old', 'description'));
+
+return AutoMapperBuilder::buildAutoMapper()->map($source, $existingData, [MapperContext::DEEP_TARGET_TO_POPULATE => true]);