Read #[Strict] also from parent classes

src/Reflection/DataTransferObjectClass.php

@@ -2,6 +2,7 @@
 
 namespace Spatie\DataTransferObject\Reflection;
 
+use ReflectionAttribute;
 use ReflectionClass;
 use ReflectionProperty;
 use Spatie\DataTransferObject\Attributes\Strict;
@@ -66,6 +67,22 @@ public function validate(): void
 
     public function isStrict(): bool
     {
-        return $this->isStrict ??= ! empty($this->reflectionClass->getAttributes(Strict::class));
+        return $this->isStrict ??= ! empty($this->getStrictAttributesWithParent($this->reflectionClass));
+    }
+
+    /**
+     * @param array<ReflectionAttribute> $attributes
+     *
+     * @return array<ReflectionAttribute>
+     */
+    private function getStrictAttributesWithParent(ReflectionClass $reflectionClass, array $attributes = []): array
+    {
+        $attributes = array_merge($attributes, $reflectionClass->getAttributes(Strict::class));
+        $parent = $reflectionClass->getParentClass();
+        if ($parent === false) {
+            return $attributes;
+        }
+
+        return $this->getStrictAttributesWithParent($parent, $attributes);
     }
 }

tests/StrictDtoTest.php

@@ -25,6 +25,17 @@ public function strict_test()
         $this->expectException(UnknownProperties::class);
 
         $dto = new StrictDto(
+            name:    'name',
+            unknown: 'unknown'
+        );
+    }
+
+    /** @test */
+    public function strict_child_test()
+    {
+        $this->expectException(UnknownProperties::class);
+
+        $dto = new ChildStrictDto(
             name: 'name',
             unknown: 'unknown'
         );
@@ -37,6 +48,9 @@ class StrictDto extends DataTransferObject
     public string $name;
 }
 
+final class ChildStrictDto extends StrictDto {}
+
+
 class NonStrictDto extends DataTransferObject
 {
     public string $name;