Cast properties with self or parent type

src/Reflection/DataTransferObjectProperty.php

@@ -7,6 +7,7 @@
 use ReflectionClass;
 use ReflectionNamedType;
 use ReflectionProperty;
+use ReflectionType;
 use ReflectionUnionType;
 use Spatie\DataTransferObject\Attributes\CastWith;
 use Spatie\DataTransferObject\Attributes\DefaultCast;
@@ -84,19 +85,21 @@ private function resolveCaster(): ?Caster
         $attribute = $attributes[0]->newInstance();
 
         return new $attribute->casterClass(
-            array_map(fn ($type) => $type->getName(), $this->extractTypes()),
+            array_map(fn ($type) => $this->resolveTypeName($type), $this->extractTypes()),
             ...$attribute->args
         );
     }
 
     private function resolveCasterFromType(): array
     {
         foreach ($this->extractTypes() as $type) {
-            if (! class_exists($type->getName())) {
+            $name = $this->resolveTypeName($type);
+
+            if (! class_exists($name)) {
                 continue;
             }
 
-            $reflectionClass = new ReflectionClass($type->getName());
+            $reflectionClass = new ReflectionClass($name);
 
             do {
                 $attributes = $reflectionClass->getAttributes(CastWith::class);
@@ -167,4 +170,13 @@ private function extractTypes(): array
             ReflectionUnionType::class => $type->getTypes(),
         };
     }
+
+    private function resolveTypeName(ReflectionType $type): string
+    {
+        return match ($type->getName()) {
+            'self' => $this->dataTransferObject::class,
+            'parent' => get_parent_class($this->dataTransferObject),
+            default => $type->getName(),
+        };
+    }
 }

tests/DataTransferObjectTest.php

@@ -6,6 +6,8 @@
 use Spatie\DataTransferObject\Tests\Dummy\ComplexDto;
 use Spatie\DataTransferObject\Tests\Dummy\ComplexDtoWithCastedAttributeHavingCast;
 use Spatie\DataTransferObject\Tests\Dummy\ComplexDtoWithNullableProperty;
+use Spatie\DataTransferObject\Tests\Dummy\ComplexDtoWithParent;
+use Spatie\DataTransferObject\Tests\Dummy\ComplexDtoWithSelf;
 use Spatie\DataTransferObject\Tests\Dummy\ComplexStrictDto;
 use Spatie\DataTransferObject\Tests\Dummy\WithDefaultValueDto;
 
@@ -208,4 +210,34 @@ public function test_clone()
         $this->assertEquals('a', $clone->name);
         $this->assertEquals('a', $clone->other->name);
     }
+
+    /** @test */
+    public function create_with_nested_self()
+    {
+        $dto = new ComplexDtoWithSelf([
+            'name' => 'a',
+            'other' => [
+                'name' => 'b',
+            ],
+        ]);
+
+        $this->assertEquals('a', $dto->name);
+        $this->assertEquals('b', $dto->other->name);
+        $this->assertNull($dto->other->other);
+    }
+
+    /** @test */
+    public function create_with_nested_parent()
+    {
+        $dto = new ComplexDtoWithParent([
+            'name' => 'a',
+            'other' => [
+                'name' => 'b',
+            ],
+        ]);
+
+        $this->assertEquals('a', $dto->name);
+        $this->assertEquals('b', $dto->other->name);
+        $this->assertNull($dto->other->other);
+    }
 }

tests/Dummy/ComplexDtoWithParent.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Spatie\DataTransferObject\Tests\Dummy;
+
+class ComplexDtoWithParent extends ComplexDtoWithSelf
+{
+    public string $name;
+
+    public ?parent $other;
+}

tests/Dummy/ComplexDtoWithSelf.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace Spatie\DataTransferObject\Tests\Dummy;
+
+use Spatie\DataTransferObject\DataTransferObject;
+
+class ComplexDtoWithSelf extends DataTransferObject
+{
+    public string $name;
+
+    public ?self $other;
+}